From 5689c7d239556a96218d13c1ba9702e6eb01deed Mon Sep 17 00:00:00 2001
From: tosmers <tosmers@8810af33-2d31-482b-a856-94f89814c4df>
Date: Thu, 23 Mar 2017 18:48:52 +0000
Subject: [PATCH] [UPDATE] - adds new export content for import to tests
 resources - exchanges Jackson back- and managed-reference annotations with
 identityInfo, ignore and identityReference annotations - adds necessary
 ObjectIdGenerator and ObjectIdResolver implementations - does not yet
 implement the generateId-Method of every ObjectIdResolver

git-svn-id: https://svn.libreccm.org/ccm/ccm_ng@4640 8810af33-2d31-482b-a856-94f89814c4df
---
 .../categorization/Categorization.java        |  8 +-
 .../CategorizationIdGenerator.java            | 69 +++++++++++++++
 .../org/libreccm/categorization/Category.java | 32 +++----
 .../categorization/CategoryIdResolver.java    | 58 +++++++++++++
 .../java/org/libreccm/core/CcmObject.java     | 12 ++-
 .../libreccm/core/CcmObjectIdResolver.java    | 51 ++++++++++++
 .../java/org/libreccm/security/Group.java     | 10 ++-
 .../libreccm/security/GroupIdResolver.java    | 51 ++++++++++++
 .../libreccm/security/GroupMarshaller.java    |  1 +
 .../libreccm/security/GroupMembership.java    | 10 ++-
 .../security/GroupMembershipIdGenerator.java  | 69 +++++++++++++++
 .../security/GroupMembershipMarshaller.java   |  7 +-
 .../java/org/libreccm/security/Party.java     | 10 ++-
 .../libreccm/security/PartyIdResolver.java    | 52 ++++++++++++
 .../org/libreccm/security/Permission.java     | 14 ++--
 .../security/PermissionIdGenerator.java       | 83 +++++++++++++++++++
 .../security/PermissionIdResolver.java        | 52 ++++++++++++
 .../main/java/org/libreccm/security/Role.java | 45 +++++-----
 .../org/libreccm/security/RoleIdResolver.java | 52 ++++++++++++
 .../org/libreccm/security/RoleMembership.java | 10 ++-
 .../security/RoleMembershipIdGenerator.java   | 69 +++++++++++++++
 .../security/RoleMembershipMarshaller.java    |  3 -
 .../main/java/org/libreccm/security/User.java |  9 +-
 .../org/libreccm/security/UserIdResolver.java | 52 ++++++++++++
 .../org/libreccm/workflow/AssignableTask.java | 10 ++-
 .../workflow/AssignableTaskIdResolver.java    | 52 ++++++++++++
 .../main/java/org/libreccm/workflow/Task.java | 16 ++--
 .../org/libreccm/workflow/TaskAssignment.java | 10 ++-
 .../workflow/TaskAssignmentIdGenerator.java   | 69 +++++++++++++++
 .../org/libreccm/workflow/TaskIdResolver.java | 52 ++++++++++++
 .../java/org/libreccm/workflow/Workflow.java  | 29 ++++---
 .../libreccm/workflow/WorkflowIdResolver.java | 52 ++++++++++++
 .../portation/CoreDataImportTest.java         | 41 ++++-----
 .../org/libreccm/portation/ImportHelper.java  | 48 +++++------
 34 files changed, 1062 insertions(+), 146 deletions(-)
 create mode 100644 ccm-core/src/main/java/org/libreccm/categorization/CategorizationIdGenerator.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/categorization/CategoryIdResolver.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/core/CcmObjectIdResolver.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/security/GroupIdResolver.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/security/GroupMembershipIdGenerator.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/security/PartyIdResolver.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/security/PermissionIdGenerator.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/security/PermissionIdResolver.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/security/RoleIdResolver.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/security/RoleMembershipIdGenerator.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/security/UserIdResolver.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/workflow/AssignableTaskIdResolver.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/workflow/TaskAssignmentIdGenerator.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/workflow/TaskIdResolver.java
 create mode 100644 ccm-core/src/main/java/org/libreccm/workflow/WorkflowIdResolver.java

diff --git a/ccm-core/src/main/java/org/libreccm/categorization/Categorization.java b/ccm-core/src/main/java/org/libreccm/categorization/Categorization.java
index a86d0a234..51cb96e39 100644
--- a/ccm-core/src/main/java/org/libreccm/categorization/Categorization.java
+++ b/ccm-core/src/main/java/org/libreccm/categorization/Categorization.java
@@ -19,6 +19,8 @@
 package org.libreccm.categorization;
 
 import com.fasterxml.jackson.annotation.JsonBackReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIdentityReference;
 import org.libreccm.core.CcmObject;
 import org.libreccm.portation.Portable;
 
@@ -96,6 +98,8 @@ import javax.persistence.FetchType;
                             + "WHERE c.category = :category "
                             + "AND c.index = TRUE")
 })
+@JsonIdentityInfo(generator = CategorizationIdGenerator.class,
+                  property = "customCatId")
 public class Categorization implements Serializable, Relation, Portable {
 
     private static final long serialVersionUID = 201504301320L;
@@ -113,7 +117,7 @@ public class Categorization implements Serializable, Relation, Portable {
      */
     @ManyToOne
     @JoinColumn(name = "CATEGORY_ID")
-    @JsonBackReference(value = "category-categorization")
+    @JsonIdentityReference(alwaysAsId = true)
     private Category category;
 
     /**
@@ -121,7 +125,7 @@ public class Categorization implements Serializable, Relation, Portable {
      */
     @ManyToOne
     @JoinColumn(name = "OBJECT_ID")
-    @JsonBackReference(value = "object-categorization")
+    @JsonIdentityReference(alwaysAsId = true)
     private CcmObject categorizedObject;
 
     /**
diff --git a/ccm-core/src/main/java/org/libreccm/categorization/CategorizationIdGenerator.java b/ccm-core/src/main/java/org/libreccm/categorization/CategorizationIdGenerator.java
new file mode 100644
index 000000000..ea1d12d4b
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/categorization/CategorizationIdGenerator.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.categorization;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class CategorizationIdGenerator extends ObjectIdGenerator<String> {
+    @Override
+    public Class<?> getScope() {
+        return Categorization.class;
+    }
+
+    @Override
+    public boolean canUseFor(ObjectIdGenerator<?> gen) {
+        return gen instanceof CategorizationIdGenerator;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> forScope(Class<?> scope) {
+        return this;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> newForSerialization(Object context) {
+        return this;
+    }
+
+    @Override
+    public IdKey key(Object key) {
+        if (key == null) {
+            return null;
+        }
+        return new IdKey(Categorization.class, Categorization.class, key);
+    }
+
+    @Override
+    public String generateId(Object forPojo) {
+        if (!(forPojo instanceof Categorization)) {
+            throw new IllegalArgumentException(
+                "Only Categorization instances are supported.");
+        }
+
+        final Categorization categorization = (Categorization) forPojo;
+
+        return String.format("{%s}{%s}",
+                categorization.getCategory().getUuid(),
+                categorization.getCategorizedObject().getUuid());
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/categorization/Category.java b/ccm-core/src/main/java/org/libreccm/categorization/Category.java
index e5a659ffa..202404be3 100644
--- a/ccm-core/src/main/java/org/libreccm/categorization/Category.java
+++ b/ccm-core/src/main/java/org/libreccm/categorization/Category.java
@@ -18,23 +18,16 @@
  */
 package org.libreccm.categorization;
 
-import static org.libreccm.categorization.CategorizationConstants.*;
-import static org.libreccm.core.CoreConstants.*;
-
-import com.fasterxml.jackson.annotation.JsonBackReference;
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIdentityReference;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
 import org.hibernate.validator.constraints.NotBlank;
 import org.libreccm.core.CcmObject;
 import org.libreccm.l10n.LocalizedString;
 import org.libreccm.portation.Portable;
 import org.libreccm.security.RecursivePermissions;
 
-import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Objects;
-
 import javax.persistence.AssociationOverride;
 import javax.persistence.Column;
 import javax.persistence.Embedded;
@@ -54,6 +47,14 @@ import javax.validation.constraints.Pattern;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlElementWrapper;
 import javax.xml.bind.annotation.XmlRootElement;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+import static org.libreccm.categorization.CategorizationConstants.CAT_XML_NS;
+import static org.libreccm.core.CoreConstants.DB_SCHEMA;
 
 /**
  * The category entity represents a single category. Each category is part of a
@@ -138,6 +139,9 @@ import javax.xml.bind.annotation.XmlRootElement;
     )
 })
 @XmlRootElement(name = "category", namespace = CAT_XML_NS)
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
+                  resolver = CategoryIdResolver.class,
+                  property = "uuid")
 public class Category extends CcmObject implements Serializable, Portable {
 
     private static final long serialVersionUID = -7250208963391878547L;
@@ -218,7 +222,7 @@ public class Category extends CcmObject implements Serializable, Portable {
     @RecursivePermissions
     @OneToMany(mappedBy = "category", fetch = FetchType.LAZY)
     @XmlElementWrapper(name = "objects", namespace = CAT_XML_NS)
-    @JsonManagedReference(value = "category-categorization")
+    @JsonIgnore
     private List<Categorization> objects;
 
     /**
@@ -228,7 +232,7 @@ public class Category extends CcmObject implements Serializable, Portable {
     @OneToMany(mappedBy = "parentCategory", fetch = FetchType.LAZY)
     @XmlElementWrapper(name = "subcategories", namespace = CAT_XML_NS)
     @XmlElement(name = "category")
-    @JsonManagedReference(value = "subcategory-parentcategory")
+    @JsonIgnore
     private List<Category> subCategories;
 
     /**
@@ -237,7 +241,7 @@ public class Category extends CcmObject implements Serializable, Portable {
      */
     @ManyToOne(fetch = FetchType.LAZY)
     @JoinColumn(name = "PARENT_CATEGORY_ID")
-    @JsonBackReference(value = "subcategory-parentcategory")
+    @JsonIdentityReference(alwaysAsId = true)
     private Category parentCategory;
 
     /**
diff --git a/ccm-core/src/main/java/org/libreccm/categorization/CategoryIdResolver.java b/ccm-core/src/main/java/org/libreccm/categorization/CategoryIdResolver.java
new file mode 100644
index 000000000..ab2c23d68
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/categorization/CategoryIdResolver.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.categorization;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+import javax.enterprise.context.RequestScoped;
+import javax.inject.Inject;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+@RequestScoped
+public class CategoryIdResolver implements ObjectIdResolver {
+    @Inject
+    private CategoryRepository categoryRepository;
+
+    @Override
+    public void bindItem(ObjectIdGenerator.IdKey idKey,
+                         Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(ObjectIdGenerator.IdKey id) {
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(Object context) {
+        return new CategoryIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(ObjectIdResolver resolverType) {
+        return resolverType instanceof CategoryIdResolver;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/core/CcmObject.java b/ccm-core/src/main/java/org/libreccm/core/CcmObject.java
index a7a914b4f..d4a722d0c 100644
--- a/ccm-core/src/main/java/org/libreccm/core/CcmObject.java
+++ b/ccm-core/src/main/java/org/libreccm/core/CcmObject.java
@@ -18,8 +18,9 @@
  */
 package org.libreccm.core;
 
-import com.fasterxml.jackson.annotation.JsonBackReference;
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
 import org.hibernate.envers.Audited;
 import org.hibernate.search.annotations.Field;
 import org.hibernate.search.annotations.IndexedEmbedded;
@@ -83,6 +84,9 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
 //persistence system we can't yet refactor it to make PMD happy. Also I think
 //this is a false warning.
 @SuppressWarnings("PMD.TooManyMethods")
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
+                  resolver = CcmObjectIdResolver.class,
+                  property = "uuid")
 public class CcmObject implements Identifiable, Serializable {
 
     private static final long serialVersionUID = 201504261329L;
@@ -122,7 +126,7 @@ public class CcmObject implements Identifiable, Serializable {
     @IndexedEmbedded(includePaths = {"grantedPrivilege", "grantee.name"})
     @XmlElementWrapper(name = "permissions", namespace = CORE_XML_NS)
     @XmlElement(name = "permission", namespace = CORE_XML_NS)
-    @JsonManagedReference(value = "object-permission")
+    @JsonIgnore
     private List<Permission> permissions;
 
     /**
@@ -131,7 +135,7 @@ public class CcmObject implements Identifiable, Serializable {
     @OneToMany(mappedBy = "categorizedObject")
     @XmlElementWrapper(name = "categories", namespace = CORE_XML_NS)
     @XmlElement(name = "category", namespace = CORE_XML_NS)
-    @JsonManagedReference(value = "object-categorization")
+    @JsonIgnore
     private List<Categorization> categories;
 
     public CcmObject() {
diff --git a/ccm-core/src/main/java/org/libreccm/core/CcmObjectIdResolver.java b/ccm-core/src/main/java/org/libreccm/core/CcmObjectIdResolver.java
new file mode 100644
index 000000000..9aca9e336
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/core/CcmObjectIdResolver.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.core;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class CcmObjectIdResolver implements ObjectIdResolver {
+    @Override
+    public void bindItem(ObjectIdGenerator.IdKey idKey,
+                         Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(ObjectIdGenerator.IdKey id) {
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(Object context) {
+        return new CcmObjectIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(ObjectIdResolver resolverType) {
+        return resolverType instanceof CcmObjectIdResolver;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/security/Group.java b/ccm-core/src/main/java/org/libreccm/security/Group.java
index 6ba0ffe31..a22055d15 100644
--- a/ccm-core/src/main/java/org/libreccm/security/Group.java
+++ b/ccm-core/src/main/java/org/libreccm/security/Group.java
@@ -18,7 +18,9 @@
  */
 package org.libreccm.security;
 
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
 import org.libreccm.portation.Portable;
 
 import javax.persistence.Entity;
@@ -33,7 +35,6 @@ import javax.persistence.Table;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlElementWrapper;
 import javax.xml.bind.annotation.XmlRootElement;
-
 import java.io.Serializable;
 import java.util.Collections;
 import java.util.HashSet;
@@ -89,6 +90,9 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
         })
 })
 @XmlRootElement(name = "user-group", namespace = CORE_XML_NS)
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
+                  resolver = GroupIdResolver.class,
+                  property = "name")
 public class Group extends Party implements Serializable, Portable {
 
     private static final long serialVersionUID = -4800759206452780739L;
@@ -100,7 +104,7 @@ public class Group extends Party implements Serializable, Portable {
     @OneToMany(mappedBy = "group")
     @XmlElementWrapper(name = "group-memberships", namespace = CORE_XML_NS)
     @XmlElement(name = "group-membership", namespace = CORE_XML_NS)
-    @JsonManagedReference(value = "group-groupmembership")
+    @JsonIgnore
     private Set<GroupMembership> memberships = new HashSet<>();
 
     public Group() {
diff --git a/ccm-core/src/main/java/org/libreccm/security/GroupIdResolver.java b/ccm-core/src/main/java/org/libreccm/security/GroupIdResolver.java
new file mode 100644
index 000000000..d531f4f31
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/security/GroupIdResolver.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.security;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class GroupIdResolver implements ObjectIdResolver {
+    @Override
+    public void bindItem(final ObjectIdGenerator.IdKey id,
+                         final Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(final ObjectIdGenerator.IdKey id) {
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(final Object context) {
+        return new GroupIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdResolver objectIdResolver) {
+        return objectIdResolver instanceof GroupIdResolver;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/security/GroupMarshaller.java b/ccm-core/src/main/java/org/libreccm/security/GroupMarshaller.java
index ed31d08e5..e841b2eb5 100644
--- a/ccm-core/src/main/java/org/libreccm/security/GroupMarshaller.java
+++ b/ccm-core/src/main/java/org/libreccm/security/GroupMarshaller.java
@@ -44,6 +44,7 @@ public class GroupMarshaller extends AbstractMarshaller<Group> {
     @Override
     @Transactional(Transactional.TxType.REQUIRED)
     protected void insertIntoDb(Group portableObject) {
+        portableObject.setPartyId(portableObject.getPartyId() * -1);
         groupRepository.save(portableObject);
     }
 }
diff --git a/ccm-core/src/main/java/org/libreccm/security/GroupMembership.java b/ccm-core/src/main/java/org/libreccm/security/GroupMembership.java
index 02fd2048f..fe2d3b07b 100644
--- a/ccm-core/src/main/java/org/libreccm/security/GroupMembership.java
+++ b/ccm-core/src/main/java/org/libreccm/security/GroupMembership.java
@@ -18,8 +18,8 @@
  */
 package org.libreccm.security;
 
-import com.fasterxml.jackson.annotation.JsonBackReference;
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIdentityReference;
 import org.libreccm.portation.Portable;
 
 import javax.persistence.Column;
@@ -54,6 +54,8 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
                 query = "SELECT m FROM GroupMembership m "
                             + "WHERE m.member = :member AND m.group = :group")})
 @XmlRootElement(name = "group-membership", namespace = CORE_XML_NS)
+@JsonIdentityInfo(generator = GroupMembershipIdGenerator.class,
+                  property = "customMemId")
 public class GroupMembership implements Serializable, Portable {
 
     private static final long serialVersionUID = 83192968306850665L;
@@ -67,13 +69,13 @@ public class GroupMembership implements Serializable, Portable {
     @ManyToOne
     @JoinColumn(name = "GROUP_ID")
     @XmlTransient
-    @JsonBackReference(value = "group-groupmembership")
+    @JsonIdentityReference(alwaysAsId = true)
     private Group group;
 
     @ManyToOne
     @JoinColumn(name = "MEMBER_ID")
     @XmlTransient
-    @JsonBackReference(value = "user-groupmembership")
+    @JsonIdentityReference(alwaysAsId = true)
     private User member;
 
     public long getMembershipId() {
diff --git a/ccm-core/src/main/java/org/libreccm/security/GroupMembershipIdGenerator.java b/ccm-core/src/main/java/org/libreccm/security/GroupMembershipIdGenerator.java
new file mode 100644
index 000000000..5393ce43a
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/security/GroupMembershipIdGenerator.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.security;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class GroupMembershipIdGenerator extends ObjectIdGenerator<String> {
+    @Override
+    public Class<?> getScope() {
+        return GroupMembership.class;
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdGenerator<?> gen) {
+        return gen instanceof GroupMembershipIdGenerator;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> forScope(final Class<?> scope) {
+        return this;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> newForSerialization(final Object context) {
+        return this;
+    }
+
+    @Override
+    public IdKey key(final Object key) {
+        if (key == null) {
+            return null;
+        }
+        return new IdKey(GroupMembership.class, GroupMembership.class, key);
+    }
+
+    @Override
+    public String generateId(final Object forPojo) {
+        if (!(forPojo instanceof GroupMembership)) {
+            throw new IllegalArgumentException(
+                    "Only GroupMembership instances are supported.");
+        }
+
+        final GroupMembership membership = (GroupMembership) forPojo;
+
+        return String.format("{%s}{%s}",
+                membership.getGroup().getName(),
+                membership.getMember().getName());
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/security/GroupMembershipMarshaller.java b/ccm-core/src/main/java/org/libreccm/security/GroupMembershipMarshaller.java
index 0b8c76c80..27439e01f 100644
--- a/ccm-core/src/main/java/org/libreccm/security/GroupMembershipMarshaller.java
+++ b/ccm-core/src/main/java/org/libreccm/security/GroupMembershipMarshaller.java
@@ -45,10 +45,7 @@ public class GroupMembershipMarshaller extends AbstractMarshaller<GroupMembershi
     @Override
     @Transactional(Transactional.TxType.REQUIRED)
     protected void insertIntoDb(GroupMembership portableObject) {
-        if (portableObject.getMembershipId() == 0) {
-            entityManager.persist(portableObject);
-        } else {
-            entityManager.merge(portableObject);
-        }
+        portableObject.setMembershipId(portableObject.getMembershipId() * -1);
+        entityManager.merge(portableObject);
     }
 }
diff --git a/ccm-core/src/main/java/org/libreccm/security/Party.java b/ccm-core/src/main/java/org/libreccm/security/Party.java
index fac24c0e5..2b84f2aa3 100644
--- a/ccm-core/src/main/java/org/libreccm/security/Party.java
+++ b/ccm-core/src/main/java/org/libreccm/security/Party.java
@@ -18,7 +18,9 @@
  */
 package org.libreccm.security;
 
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
 
 import javax.persistence.Column;
 import javax.persistence.Entity;
@@ -38,7 +40,6 @@ import javax.validation.constraints.NotNull;
 import javax.validation.constraints.Pattern;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlElementWrapper;
-
 import java.io.Serializable;
 import java.util.Collections;
 import java.util.HashSet;
@@ -73,6 +74,9 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
                       attributeNodes = @NamedAttributeNode(
                           value = "roleMemberships"))
 })
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
+                  resolver = PartyIdResolver.class,
+                  property = "name")
 public class Party implements Serializable {
 
     private static final long serialVersionUID = 3319997992281332204L;
@@ -97,7 +101,7 @@ public class Party implements Serializable {
     @OneToMany(mappedBy = "member")
     @XmlElementWrapper(name = "role-memberships", namespace = CORE_XML_NS)
     @XmlElement(name = "role-membership", namespace = CORE_XML_NS)
-    @JsonManagedReference(value = "party-rolemembership")
+    @JsonIgnore
     private Set<RoleMembership> roleMemberships = new HashSet<>();
 
     protected Party() {
diff --git a/ccm-core/src/main/java/org/libreccm/security/PartyIdResolver.java b/ccm-core/src/main/java/org/libreccm/security/PartyIdResolver.java
new file mode 100644
index 000000000..7192059c9
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/security/PartyIdResolver.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.security;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class PartyIdResolver implements ObjectIdResolver {
+    @Override
+    public void bindItem(final ObjectIdGenerator.IdKey id,
+                         final Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(final ObjectIdGenerator.IdKey id) {
+        // Find the user for the id (don't confuse that with the primary key!).
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(final Object context) {
+        return new PartyIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdResolver resolverType) {
+        return resolverType instanceof PartyIdResolver;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/security/Permission.java b/ccm-core/src/main/java/org/libreccm/security/Permission.java
index 0d08fb2ea..187430fe0 100644
--- a/ccm-core/src/main/java/org/libreccm/security/Permission.java
+++ b/ccm-core/src/main/java/org/libreccm/security/Permission.java
@@ -18,7 +18,8 @@
  */
 package org.libreccm.security;
 
-import com.fasterxml.jackson.annotation.JsonBackReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIdentityReference;
 import org.hibernate.search.annotations.ContainedIn;
 import org.hibernate.search.annotations.Field;
 import org.hibernate.search.annotations.IndexedEmbedded;
@@ -34,6 +35,7 @@ import javax.persistence.JoinColumn;
 import javax.persistence.ManyToOne;
 import javax.persistence.NamedQueries;
 import javax.persistence.NamedQuery;
+import javax.persistence.OneToOne;
 import javax.persistence.Table;
 import javax.persistence.Temporal;
 import javax.persistence.TemporalType;
@@ -41,7 +43,6 @@ import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlRootElement;
-
 import java.io.Serializable;
 import java.util.Date;
 import java.util.Objects;
@@ -49,8 +50,6 @@ import java.util.Objects;
 import static org.libreccm.core.CoreConstants.CORE_XML_NS;
 import static org.libreccm.core.CoreConstants.DB_SCHEMA;
 
-import javax.persistence.OneToOne;
-
 /**
  * A permission grants a privilege on an object or system wide to {@link Role}.
  *
@@ -100,6 +99,9 @@ import javax.persistence.OneToOne;
 })
 @XmlRootElement(name = "permission", namespace = CORE_XML_NS)
 @XmlAccessorType(XmlAccessType.FIELD)
+@JsonIdentityInfo(generator = PermissionIdGenerator.class,
+                  resolver = PermissionIdResolver.class,
+                  property = "customPermId")
 public class Permission implements Serializable, Portable {
 
     private static final long serialVersionUID = -5178045844045517958L;
@@ -127,7 +129,7 @@ public class Permission implements Serializable, Portable {
     @ManyToOne
     @JoinColumn(name = "OBJECT_ID")
     @ContainedIn
-    @JsonBackReference(value = "object-permission")
+    @JsonIdentityReference(alwaysAsId = true)
     private CcmObject object;
 
     /**
@@ -136,7 +138,7 @@ public class Permission implements Serializable, Portable {
     @ManyToOne
     @IndexedEmbedded
     @JoinColumn(name = "GRANTEE_ID")
-    @JsonBackReference(value = "role-permission")
+    @JsonIdentityReference(alwaysAsId = true)
     private Role grantee;
 
     /**
diff --git a/ccm-core/src/main/java/org/libreccm/security/PermissionIdGenerator.java b/ccm-core/src/main/java/org/libreccm/security/PermissionIdGenerator.java
new file mode 100644
index 000000000..34f062763
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/security/PermissionIdGenerator.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.security;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class PermissionIdGenerator extends ObjectIdGenerator<String> {
+    @Override
+    public Class<?> getScope() {
+        return Permission.class;
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdGenerator<?> gen) {
+        return gen instanceof PermissionIdGenerator;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> forScope(final Class<?> scope) {
+        return this;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> newForSerialization(final Object context) {
+        return this;
+    }
+
+    @Override
+    public IdKey key(final Object key) {
+        if (key == null) {
+            return null;
+        }
+        return new IdKey(Permission.class, Permission.class, key);
+    }
+
+    @Override
+    public String generateId(final Object forPojo) {
+        if (!(forPojo instanceof Permission)) {
+            throw new IllegalArgumentException(
+                    "Only Permission instances are supported.");
+        }
+
+        final Permission permission = (Permission) forPojo;
+
+        String id = permission.getGrantedPrivilege() +
+                permission.getPermissionId();
+        boolean a = false, b = false;
+        if (permission.getObject() != null) {
+            id += permission.getObject().getUuid();
+            a = true;
+        }
+        if (permission.getGrantee() != null) {
+            id += permission.getGrantee().getName();
+            b = true;
+        }
+
+//        if (!(a || b)) {
+//            throw new IllegalStateException();
+//        }
+
+        return id;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/security/PermissionIdResolver.java b/ccm-core/src/main/java/org/libreccm/security/PermissionIdResolver.java
new file mode 100644
index 000000000..58897b63c
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/security/PermissionIdResolver.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.security;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class PermissionIdResolver implements ObjectIdResolver {
+    @Override
+    public void bindItem(final ObjectIdGenerator.IdKey id,
+                         final Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(final ObjectIdGenerator.IdKey id) {
+        // Find the user for the id (don't confuse that with the primary key!).
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(final Object context) {
+        return new PermissionIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdResolver resolverType) {
+        return resolverType instanceof PermissionIdResolver;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/security/Role.java b/ccm-core/src/main/java/org/libreccm/security/Role.java
index 30618a2e1..2bc4e95eb 100644
--- a/ccm-core/src/main/java/org/libreccm/security/Role.java
+++ b/ccm-core/src/main/java/org/libreccm/security/Role.java
@@ -18,7 +18,10 @@
  */
 package org.libreccm.security;
 
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
+import org.hibernate.search.annotations.Field;
 import org.hibernate.validator.constraints.NotBlank;
 import org.libreccm.l10n.LocalizedString;
 import org.libreccm.portation.Portable;
@@ -46,7 +49,6 @@ import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlElementWrapper;
 import javax.xml.bind.annotation.XmlRootElement;
-
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -55,8 +57,6 @@ import java.util.List;
 import java.util.Objects;
 import java.util.Set;
 
-import org.hibernate.search.annotations.Field;
-
 import static org.libreccm.core.CoreConstants.CORE_XML_NS;
 import static org.libreccm.core.CoreConstants.DB_SCHEMA;
 
@@ -134,6 +134,9 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
 @XmlRootElement(name = "role", namespace = CORE_XML_NS)
 @XmlAccessorType(XmlAccessType.FIELD)
 @SuppressWarnings({"PMD.ShortClassName", "PMD.TooManyMethods"})
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
+                  resolver = RoleIdResolver.class,
+                  property = "name")
 public class Role implements Serializable, Portable {
 
     private static final long serialVersionUID = -7121296514181469687L;
@@ -160,13 +163,27 @@ public class Role implements Serializable, Portable {
     @XmlElement(name = "name", namespace = CORE_XML_NS)
     private String name;
 
+    /**
+     * An optional description for a role.
+     */
+    @Embedded
+    @AssociationOverride(
+            name = "values",
+            joinTable = @JoinTable(name = "ROLE_DESCRIPTIONS",
+                    schema = DB_SCHEMA,
+                    joinColumns = {
+                            @JoinColumn(name = "ROLE_ID")
+                    }))
+    @XmlElement(name = "description", namespace = CORE_XML_NS)
+    private LocalizedString description = new LocalizedString();
+
     /**
      * All memberships of the roles.
      */
     @OneToMany(mappedBy = "role")
     @XmlElementWrapper(name = "role-memberships", namespace = CORE_XML_NS)
     @XmlElement(name = "role-membership", namespace = CORE_XML_NS)
-    @JsonManagedReference(value = "role-rolemembership")
+    @JsonIgnore
     private Set<RoleMembership> memberships = new HashSet<>();
 
     /**
@@ -175,27 +192,13 @@ public class Role implements Serializable, Portable {
     @OneToMany(mappedBy = "grantee")
     @XmlElementWrapper(name = "permissions", namespace = CORE_XML_NS)
     @XmlElement(name = "permission", namespace = CORE_XML_NS)
-    @JsonManagedReference(value = "role-permission")
+    @JsonIgnore
     private List<Permission> permissions = new ArrayList<>();
 
     @OneToMany(mappedBy = "role")
-    @JsonManagedReference(value = "role-taskassignment")
+    @JsonIgnore
     private List<TaskAssignment> assignedTasks = new ArrayList<>();
 
-    /**
-     * An optional description for a role.
-     */
-    @Embedded
-    @AssociationOverride(
-            name = "values",
-            joinTable = @JoinTable(name = "ROLE_DESCRIPTIONS",
-                                   schema = DB_SCHEMA,
-                                   joinColumns = {
-                                       @JoinColumn(name = "ROLE_ID")
-                                   }))
-    @XmlElement(name = "description", namespace = CORE_XML_NS)
-    private LocalizedString description = new LocalizedString(); 
-
     public Role() {
         super();
     }
diff --git a/ccm-core/src/main/java/org/libreccm/security/RoleIdResolver.java b/ccm-core/src/main/java/org/libreccm/security/RoleIdResolver.java
new file mode 100644
index 000000000..061cca93a
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/security/RoleIdResolver.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.security;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class RoleIdResolver implements ObjectIdResolver {
+    @Override
+    public void bindItem(final ObjectIdGenerator.IdKey id,
+                         final Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(final ObjectIdGenerator.IdKey id) {
+        // Find the user for the id (don't confuse that with the primary key!).
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(final Object context) {
+        return new RoleIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdResolver resolverType) {
+        return resolverType instanceof RoleIdResolver;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/security/RoleMembership.java b/ccm-core/src/main/java/org/libreccm/security/RoleMembership.java
index a3a467305..81a5e3979 100644
--- a/ccm-core/src/main/java/org/libreccm/security/RoleMembership.java
+++ b/ccm-core/src/main/java/org/libreccm/security/RoleMembership.java
@@ -18,8 +18,8 @@
  */
 package org.libreccm.security;
 
-import com.fasterxml.jackson.annotation.JsonBackReference;
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIdentityReference;
 import org.libreccm.portation.Portable;
 
 import javax.persistence.Column;
@@ -55,6 +55,8 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
                             + "WHERE m.member = :member AND m.role = :role")
 })
 @XmlRootElement(name = "role-membership", namespace = CORE_XML_NS)
+@JsonIdentityInfo(generator = RoleMembershipIdGenerator.class,
+                  property = "customMemId")
 public class RoleMembership implements Serializable, Portable {
 
     private static final long serialVersionUID = -3049727720697964793L;
@@ -68,13 +70,13 @@ public class RoleMembership implements Serializable, Portable {
     @ManyToOne
     @JoinColumn(name = "ROLE_ID")
     @XmlTransient
-    @JsonBackReference(value = "role-rolemembership")
+    @JsonIdentityReference(alwaysAsId = true)
     private Role role;
 
     @ManyToOne
     @JoinColumn(name = "MEMBER_ID")
     @XmlTransient
-    @JsonBackReference(value = "party-rolemembership")
+    @JsonIdentityReference(alwaysAsId = true)
     private Party member;
 
     public long getMembershipId() {
diff --git a/ccm-core/src/main/java/org/libreccm/security/RoleMembershipIdGenerator.java b/ccm-core/src/main/java/org/libreccm/security/RoleMembershipIdGenerator.java
new file mode 100644
index 000000000..1bf194747
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/security/RoleMembershipIdGenerator.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.security;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class RoleMembershipIdGenerator extends ObjectIdGenerator<String> {
+    @Override
+    public Class<?> getScope() {
+        return RoleMembership.class;
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdGenerator<?> gen) {
+        return gen instanceof RoleMembershipIdGenerator;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> forScope(final Class<?> scope) {
+        return this;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> newForSerialization(final Object context) {
+        return this;
+    }
+
+    @Override
+    public IdKey key(final Object key) {
+        if (key == null) {
+            return null;
+        }
+        return new IdKey(RoleMembership.class, RoleMembership.class, key);
+    }
+
+    @Override
+    public String generateId(final Object forPojo) {
+        if (!(forPojo instanceof RoleMembership)) {
+            throw new IllegalArgumentException(
+                    "Only RoleMembership instances are supported.");
+        }
+
+        final RoleMembership membership = (RoleMembership) forPojo;
+
+        return String.format("{%s}{%s}",
+                membership.getRole().getName(),
+                membership.getMember().getName());
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/security/RoleMembershipMarshaller.java b/ccm-core/src/main/java/org/libreccm/security/RoleMembershipMarshaller.java
index 26d90fb70..0efcd0eac 100644
--- a/ccm-core/src/main/java/org/libreccm/security/RoleMembershipMarshaller.java
+++ b/ccm-core/src/main/java/org/libreccm/security/RoleMembershipMarshaller.java
@@ -59,9 +59,6 @@ public class RoleMembershipMarshaller extends AbstractMarshaller<RoleMembership>
             final RoleMembership roleMembership = save(portableObject);
         LOGGER.debug("Saved RoleMembership with id {}.",
                      roleMembership.getMembershipId());
-//        } else {
-//            entityManager.merge(portableObject);
-//        }
     }
     
     @Transactional(Transactional.TxType.REQUIRES_NEW)
diff --git a/ccm-core/src/main/java/org/libreccm/security/User.java b/ccm-core/src/main/java/org/libreccm/security/User.java
index c7a437b8e..a678bce96 100644
--- a/ccm-core/src/main/java/org/libreccm/security/User.java
+++ b/ccm-core/src/main/java/org/libreccm/security/User.java
@@ -18,7 +18,10 @@
  */
 package org.libreccm.security;
 
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
 import org.libreccm.core.EmailAddress;
 import org.libreccm.portation.Portable;
 
@@ -46,7 +49,6 @@ import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.XmlElementWrapper;
 import javax.xml.bind.annotation.XmlRootElement;
 import javax.xml.bind.annotation.XmlTransient;
-
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -126,6 +128,9 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
 //Supressing a few warnings from PMD because they misleading here.
 //User is perfectly fine class name, and the complexity is not to high...
 @SuppressWarnings({"PMD.ShortClassName", "PMD.LongVariable"})
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
+                  resolver = UserIdResolver.class,
+                  property = "name")
 public class User extends Party implements Serializable, Portable {
 
     private static final long serialVersionUID = 4035223413596611393L;
@@ -203,7 +208,7 @@ public class User extends Party implements Serializable, Portable {
     @OneToMany(mappedBy = "member")
     @XmlElementWrapper(name = "group-memberships", namespace = CORE_XML_NS)
     @XmlElement(name = "group-membership", namespace = CORE_XML_NS)
-    @JsonManagedReference(value = "user-groupmembership")
+    @JsonIgnore
     private Set<GroupMembership> groupMemberships = new HashSet<>();
 
     protected User() {
diff --git a/ccm-core/src/main/java/org/libreccm/security/UserIdResolver.java b/ccm-core/src/main/java/org/libreccm/security/UserIdResolver.java
new file mode 100644
index 000000000..cea3c2768
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/security/UserIdResolver.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.security;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class UserIdResolver implements ObjectIdResolver {
+    @Override
+    public void bindItem(final ObjectIdGenerator.IdKey id,
+                         final Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(final ObjectIdGenerator.IdKey id) {
+        // Find the user for the id (don't confuse that with the primary key!).
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(final Object context) {
+        return new UserIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdResolver resolverType) {
+        return resolverType instanceof UserIdResolver;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/workflow/AssignableTask.java b/ccm-core/src/main/java/org/libreccm/workflow/AssignableTask.java
index c04be08a0..0e0af38f0 100644
--- a/ccm-core/src/main/java/org/libreccm/workflow/AssignableTask.java
+++ b/ccm-core/src/main/java/org/libreccm/workflow/AssignableTask.java
@@ -18,8 +18,9 @@
  */
 package org.libreccm.workflow;
 
-import com.fasterxml.jackson.annotation.JsonBackReference;
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
 import org.libreccm.portation.Portable;
 import org.libreccm.security.User;
 
@@ -81,6 +82,9 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
 @SuppressWarnings({"PMD.CyclomaticComplexity",
                    "PMD.StdCyclomaticComplexity",
                    "PMD.ModifiedCyclomaticComplexity"})
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
+                  resolver = AssignableTaskIdResolver.class,
+                  property = "uuid")
 public class AssignableTask extends Task implements Serializable, Portable {
 
     private static final long serialVersionUID = 4188064584389893019L;
@@ -130,7 +134,7 @@ public class AssignableTask extends Task implements Serializable, Portable {
      * The roles to which task is assigned.
      */
     @OneToMany(mappedBy = "task")
-    @JsonManagedReference(value = "assignabletask-taskassignment")
+    @JsonIgnore
     private List<TaskAssignment> assignments;
 
     public AssignableTask() {
diff --git a/ccm-core/src/main/java/org/libreccm/workflow/AssignableTaskIdResolver.java b/ccm-core/src/main/java/org/libreccm/workflow/AssignableTaskIdResolver.java
new file mode 100644
index 000000000..c1bb90df4
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/workflow/AssignableTaskIdResolver.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.workflow;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class AssignableTaskIdResolver implements ObjectIdResolver {
+    @Override
+    public void bindItem(final ObjectIdGenerator.IdKey id,
+                         final Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(final ObjectIdGenerator.IdKey id) {
+        // Find the user for the id (don't confuse that with the primary key!).
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(final Object context) {
+        return new AssignableTaskIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdResolver resolverType) {
+        return resolverType instanceof AssignableTaskIdResolver;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/workflow/Task.java b/ccm-core/src/main/java/org/libreccm/workflow/Task.java
index ba7c9426b..5fa2b3771 100644
--- a/ccm-core/src/main/java/org/libreccm/workflow/Task.java
+++ b/ccm-core/src/main/java/org/libreccm/workflow/Task.java
@@ -18,8 +18,9 @@
  */
 package org.libreccm.workflow;
 
-import com.fasterxml.jackson.annotation.JsonBackReference;
 import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIdentityReference;
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.ObjectIdGenerators;
 import org.libreccm.core.CcmObject;
 import org.libreccm.core.Identifiable;
@@ -98,6 +99,9 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
                     + "WHERE t.workflow = :workflow "
                     + "AND t.taskState = org.libreccm.workflow.TaskState.FINISHED")
 })
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
+                  resolver = TaskIdResolver.class,
+                  property = "uuid")
 public class Task implements Identifiable, Serializable {
 
     private static final long serialVersionUID = 8161343036908150426L;
@@ -159,16 +163,14 @@ public class Task implements Identifiable, Serializable {
      */
     @ManyToOne
     @JoinColumn(name = "WORKFLOW_ID")
-    @JsonBackReference(value = "workflow-task")
+    @JsonIdentityReference(alwaysAsId = true)
     private Workflow workflow;
 
     /**
      * Tasks which the depends of this task.
      */
     @ManyToMany(mappedBy = "dependsOn")
-    @JsonIdentityInfo(
-            generator = ObjectIdGenerators.PropertyGenerator.class,
-            property = "taskId")
+    @JsonIgnore
     private List<Task> dependentTasks;
 
     /**
@@ -181,9 +183,7 @@ public class Task implements Identifiable, Serializable {
                    @JoinColumn(name = "DEPENDS_ON_TASK_ID")},
                inverseJoinColumns = {
                    @JoinColumn(name = "DEPENDENT_TASK_ID")})
-    @JsonIdentityInfo(
-            generator = ObjectIdGenerators.PropertyGenerator.class,
-            property = "taskId")
+    @JsonIdentityReference(alwaysAsId = true)
     private List<Task> dependsOn;
 
     /**
diff --git a/ccm-core/src/main/java/org/libreccm/workflow/TaskAssignment.java b/ccm-core/src/main/java/org/libreccm/workflow/TaskAssignment.java
index e6bd89be6..e55b1016d 100644
--- a/ccm-core/src/main/java/org/libreccm/workflow/TaskAssignment.java
+++ b/ccm-core/src/main/java/org/libreccm/workflow/TaskAssignment.java
@@ -18,8 +18,8 @@
  */
 package org.libreccm.workflow;
 
-import com.fasterxml.jackson.annotation.JsonBackReference;
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIdentityReference;
 import org.libreccm.portation.Portable;
 import org.libreccm.security.Role;
 
@@ -43,6 +43,8 @@ import static org.libreccm.core.CoreConstants.DB_SCHEMA;
  */
 @Entity
 @Table(name = "WORKFLOW_TASK_ASSIGNMENTS", schema = DB_SCHEMA)
+@JsonIdentityInfo(generator = TaskAssignmentIdGenerator.class,
+                  property = "customAssignId")
 public class TaskAssignment implements Serializable, Portable {
 
     private static final long serialVersionUID = -4427537363301565707L;
@@ -60,7 +62,7 @@ public class TaskAssignment implements Serializable, Portable {
      */
     @ManyToOne
     @JoinColumn(name = "TASK_ID")
-    @JsonBackReference(value = "assignabletask-taskassignment")
+    @JsonIdentityReference(alwaysAsId = true)
     private AssignableTask task;
 
     /**
@@ -68,7 +70,7 @@ public class TaskAssignment implements Serializable, Portable {
      */
     @ManyToOne
     @JoinColumn(name = "ROLE_ID")
-    @JsonBackReference(value = "role-taskassignment")
+    @JsonIdentityReference(alwaysAsId = true)
     private Role role;
 
     public long getTaskAssignmentId() {
diff --git a/ccm-core/src/main/java/org/libreccm/workflow/TaskAssignmentIdGenerator.java b/ccm-core/src/main/java/org/libreccm/workflow/TaskAssignmentIdGenerator.java
new file mode 100644
index 000000000..c59574c8e
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/workflow/TaskAssignmentIdGenerator.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.workflow;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class TaskAssignmentIdGenerator extends ObjectIdGenerator<String> {
+    @Override
+    public Class<?> getScope() {
+        return TaskAssignment.class;
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdGenerator<?> gen) {
+        return gen instanceof TaskAssignmentIdGenerator;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> forScope(final Class<?> scope) {
+        return this;
+    }
+
+    @Override
+    public ObjectIdGenerator<String> newForSerialization(final Object context) {
+        return this;
+    }
+
+    @Override
+    public IdKey key(final Object key) {
+        if (key == null) {
+            return null;
+        }
+        return new IdKey(TaskAssignment.class, TaskAssignment.class, key);
+    }
+
+    @Override
+    public String generateId(final Object forPojo) {
+        if (!(forPojo instanceof TaskAssignment)) {
+            throw new IllegalArgumentException(
+                    "Only RoleMembership instances are supported.");
+        }
+
+        final TaskAssignment assignment = (TaskAssignment) forPojo;
+
+        return String.format("{%s}{%s}",
+                assignment.getTask().getUuid(),
+                assignment.getRole().getName());
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/workflow/TaskIdResolver.java b/ccm-core/src/main/java/org/libreccm/workflow/TaskIdResolver.java
new file mode 100644
index 000000000..f48f4f587
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/workflow/TaskIdResolver.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.workflow;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class TaskIdResolver implements ObjectIdResolver {
+    @Override
+    public void bindItem(final ObjectIdGenerator.IdKey id,
+                         final Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(final ObjectIdGenerator.IdKey id) {
+        // Find the user for the id (don't confuse that with the primary key!).
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(final Object context) {
+        return new TaskIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdResolver resolverType) {
+        return resolverType instanceof TaskIdResolver;
+    }
+}
diff --git a/ccm-core/src/main/java/org/libreccm/workflow/Workflow.java b/ccm-core/src/main/java/org/libreccm/workflow/Workflow.java
index 6749796b0..1e2329325 100644
--- a/ccm-core/src/main/java/org/libreccm/workflow/Workflow.java
+++ b/ccm-core/src/main/java/org/libreccm/workflow/Workflow.java
@@ -18,18 +18,13 @@
  */
 package org.libreccm.workflow;
 
-import static org.libreccm.core.CoreConstants.*;
-
-import com.fasterxml.jackson.annotation.JsonBackReference;
-import com.fasterxml.jackson.annotation.JsonManagedReference;
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
 import org.libreccm.core.CcmObject;
+import org.libreccm.core.Identifiable;
 import org.libreccm.l10n.LocalizedString;
-
-import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Objects;
+import org.libreccm.portation.Portable;
 
 import javax.persistence.AssociationOverride;
 import javax.persistence.Column;
@@ -51,8 +46,13 @@ import javax.persistence.OneToMany;
 import javax.persistence.OneToOne;
 import javax.persistence.Table;
 import javax.validation.constraints.NotNull;
-import org.libreccm.core.Identifiable;
-import org.libreccm.portation.Portable;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+import static org.libreccm.core.CoreConstants.DB_SCHEMA;
 
 /**
  * A workflow is a collection of tasks which are performed on an object. Tasks
@@ -73,6 +73,9 @@ import org.libreccm.portation.Portable;
         query = "SELECT w FROM Workflow w "
                     + "WHERE W.object = :object")
 })
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
+                  resolver = WorkflowIdResolver.class,
+                  property = "uuid")
 public class Workflow implements Identifiable, Serializable, Portable {
 
     private static final long serialVersionUID = 4322500264543325829L;
@@ -157,7 +160,7 @@ public class Workflow implements Identifiable, Serializable, Portable {
      * The tasks belonging to this workflow.
      */
     @OneToMany(mappedBy = "workflow")
-    @JsonManagedReference(value = "workflow-task")
+    @JsonIgnore
     private List<Task> tasks;
 
     public Workflow() {
diff --git a/ccm-core/src/main/java/org/libreccm/workflow/WorkflowIdResolver.java b/ccm-core/src/main/java/org/libreccm/workflow/WorkflowIdResolver.java
new file mode 100644
index 000000000..65de496ef
--- /dev/null
+++ b/ccm-core/src/main/java/org/libreccm/workflow/WorkflowIdResolver.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2015 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.libreccm.workflow;
+
+import com.fasterxml.jackson.annotation.ObjectIdGenerator;
+import com.fasterxml.jackson.annotation.ObjectIdResolver;
+
+/**
+ * @author <a href="mailto:tosmers@uni-bremen.de>Tobias Osmers</a>
+ * @version created on 3/23/17
+ */
+public class WorkflowIdResolver implements ObjectIdResolver {
+    @Override
+    public void bindItem(final ObjectIdGenerator.IdKey id,
+                         final Object pojo) {
+        // According to the Jackson JavaDoc, this method can be used to keep
+        // track of objects directly in a resolver implementation. We don't need
+        // this here therefore this method is empty.
+    }
+
+    @Override
+    public Object resolveId(final ObjectIdGenerator.IdKey id) {
+        // Find the user for the id (don't confuse that with the primary key!).
+        return null;
+    }
+
+    @Override
+    public ObjectIdResolver newForDeserialization(final Object context) {
+        return new WorkflowIdResolver();
+    }
+
+    @Override
+    public boolean canUseFor(final ObjectIdResolver resolverType) {
+        return resolverType instanceof WorkflowIdResolver;
+    }
+}
diff --git a/ccm-core/src/test/java/org/libreccm/portation/CoreDataImportTest.java b/ccm-core/src/test/java/org/libreccm/portation/CoreDataImportTest.java
index f8a336f13..73c2305cd 100644
--- a/ccm-core/src/test/java/org/libreccm/portation/CoreDataImportTest.java
+++ b/ccm-core/src/test/java/org/libreccm/portation/CoreDataImportTest.java
@@ -24,6 +24,7 @@ import org.jboss.arquillian.junit.InSequence;
 import org.jboss.arquillian.persistence.CleanupUsingScript;
 import org.jboss.arquillian.persistence.CreateSchema;
 import org.jboss.arquillian.persistence.PersistenceTest;
+import org.jboss.arquillian.persistence.TestExecutionPhase;
 import org.jboss.arquillian.transaction.api.annotation.TransactionMode;
 import org.jboss.arquillian.transaction.api.annotation.Transactional;
 import org.jboss.shrinkwrap.api.ShrinkWrap;
@@ -39,9 +40,7 @@ import org.junit.experimental.categories.Category;
 import org.junit.runner.RunWith;
 import org.libreccm.tests.categories.IntegrationTest;
 
-import javax.faces.bean.RequestScoped;
 import javax.inject.Inject;
-import org.jboss.arquillian.persistence.TestExecutionPhase;
 
 import static org.libreccm.testutils.DependenciesHelpers.getModuleDependencies;
 
@@ -127,79 +126,75 @@ public class CoreDataImportTest {
     // TEST SECTION
 
     @Test
-    @InSequence(105)
-    public void categoriesShouldBeImported() {
+    @InSequence(115)
+    public void  roleMembershipsShouldBeImported() {
         Assert.assertFalse(importHelper.importRoleMemberships());
     }
 
-    //@Test
+    @Test
     @InSequence(110)
-    public void categorizationsShouldBeImported() {
-        importHelper.importGroupMemberships();
+    public void groupMembershipsShouldBeImported() {
+        Assert.assertFalse(importHelper.importGroupMemberships());
     }
 
-    //@Test
+    @Test
     @InSequence(115)
-    public void usersShouldBeImported() {
-        importHelper.importGroups();
+    public void groupsShouldBeImported() {
+        Assert.assertFalse(importHelper.importGroups());
     }
 
     //@Test
     @InSequence(120)
-    public void groupsShouldBeImported() {
+    public void usersShouldBeImported() {
         importHelper.importUsers();
     }
 
     //@Test
     @InSequence(125)
-    public void groupMembershipsShouldBeImported() {
+    public void taskAssignmentsMembershipsShouldBeImported() {
         importHelper.importTaskAssignments();
     }
 
     //@Test
     @InSequence(130)
-    public void rolesShouldBeImported() {
+    public void assignableTasksShouldBeImported() {
         importHelper.importAssignableTasks();
     }
 
     //@Test
     @InSequence(135)
-    public void roleMembershipsShouldBeImported() {
+    public void workflowTemplatesShouldBeImported() {
         importHelper.importWorkflowTemplates();
     }
 
     //@Test
     @InSequence(140)
-    public void workflowTemplatesShouldBeImported() {
+    public void workflowsShouldBeImported() {
         importHelper.importWorkflows();
     }
 
-
-
-
     //@Test
     @InSequence(145)
-    public void workflowsShouldBeImported() {
+    public void categorizationsShouldBeImported() {
         importHelper.importCategorizations();
     }
 
     //@Test
     @InSequence(150)
-    public void assignableTasksShouldBeImported() {
+    public void PermissionsShouldBeImported() {
         importHelper.importPermissions();
     }
 
     //@Test
     @InSequence(155)
-    public void taskAssignmentsShouldBeImported() {
+    public void categoriesShouldBeImported() {
         importHelper.importCategories();
     }
 
     //@Test
     @InSequence(160)
-    public void permissionsShouldBeImported() {
+    public void rolesShouldBeImported() {
         importHelper.importRoles();
     }
 
-
 }
diff --git a/ccm-core/src/test/java/org/libreccm/portation/ImportHelper.java b/ccm-core/src/test/java/org/libreccm/portation/ImportHelper.java
index 5bbf65d22..15e2e4c9c 100644
--- a/ccm-core/src/test/java/org/libreccm/portation/ImportHelper.java
+++ b/ccm-core/src/test/java/org/libreccm/portation/ImportHelper.java
@@ -55,8 +55,8 @@ import javax.inject.Inject;
  */
 @RequestScoped
 class ImportHelper {
-    private String repoPath = "/home/jensp/pwi/libreccm/ccm/";
-    //private String repoPath = "";
+    //private String repoPath = "/home/jensp/pwi/libreccm/ccm/";
+    private String repoPath = "/home/tosmers/Svn/libreccm/";
     private String projectPath = "ccm_ng/ccm-core/src/test/resources/" +
                     "portation/trunk-iaw-exports";
     private boolean indentation = false;
@@ -99,40 +99,40 @@ class ImportHelper {
     private PermissionMarshaller permissionMarshaller;
 
 
-    void importCategories() {
+    boolean importCategories() {
         categoryMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "categories.xml", indentation);
-        categoryMarshaller.importFile();
+        return categoryMarshaller.importFile();
     }
 
-    void importCategorizations() {
+    boolean importCategorizations() {
         categorizationMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "categorizations.xml", indentation);
-        categorizationMarshaller.importFile();
+        return categorizationMarshaller.importFile();
     }
 
-    void importUsers() {
+    boolean importUsers() {
         userMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "users.xml", indentation);
-        userMarshaller.importFile();
+        return userMarshaller.importFile();
     }
 
-    void importGroups() {
+    boolean importGroups() {
         groupMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "groups.xml", indentation);
-        groupMarshaller.importFile();
+        return groupMarshaller.importFile();
     }
 
-    void importGroupMemberships() {
+    boolean importGroupMemberships() {
         groupMembershipMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "groupMemberships.xml", indentation);
-        groupMembershipMarshaller.importFile();
+        return groupMembershipMarshaller.importFile();
     }
 
-    void importRoles() {
+    boolean importRoles() {
         roleMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "roles.xml", indentation);
-        roleMarshaller.importFile();
+        return roleMarshaller.importFile();
     }
 
     boolean importRoleMemberships() {
@@ -141,34 +141,34 @@ class ImportHelper {
         return roleMembershipMarshaller.importFile();
     }
 
-    void importWorkflowTemplates() {
+    boolean importWorkflowTemplates() {
         workflowTemplateMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "workflowTemplates.xml", indentation);
-        workflowTemplateMarshaller.importFile();
+        return workflowTemplateMarshaller.importFile();
     }
 
-    void importWorkflows() {
+    boolean importWorkflows() {
         workflowMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "workflows.xml", indentation);
-        workflowMarshaller.importFile();
+        return workflowMarshaller.importFile();
     }
 
-    void importAssignableTasks() {
+    boolean importAssignableTasks() {
         assignableTaskMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "assignableTasks.xml", indentation);
-        assignableTaskMarshaller.importFile();
+        return assignableTaskMarshaller.importFile();
     }
 
-    void importTaskAssignments() {
+    boolean importTaskAssignments() {
         taskAssignmentMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "taskAssignments.xml", indentation);
-        taskAssignmentMarshaller.importFile();
+        return taskAssignmentMarshaller.importFile();
     }
 
-    void importPermissions() {
+    boolean importPermissions() {
         permissionMarshaller.prepare(Format.XML, repoPath + projectPath,
                 "permissions.xml", indentation);
-        permissionMarshaller.importFile();
+        return permissionMarshaller.importFile();
     }
 
 }