Optmiziations for the RESTful API managing containers of page models

ccm-core/src/main/java/org/libreccm/api/pagemodels/Containers.java

@@ -18,6 +18,8 @@
  */
 package org.libreccm.api.pagemodels;
 
+import org.libreccm.api.dto.ListView;
+import org.libreccm.api.pagemodels.dto.ContainerModelDto;
 import org.libreccm.core.CoreConstants;
 import org.libreccm.pagemodel.ContainerModel;
 import org.libreccm.pagemodel.ContainerModelRepository;
@@ -29,21 +31,20 @@ import org.libreccm.web.CcmApplication;
 
 import java.net.URI;
 import java.util.Optional;
+import java.util.stream.Collectors;
 
 import javax.enterprise.context.RequestScoped;
 import javax.inject.Inject;
-import javax.json.Json;
-import javax.json.JsonArray;
-import javax.json.JsonArrayBuilder;
-import javax.json.JsonObject;
 import javax.transaction.Transactional;
 import javax.ws.rs.Consumes;
 import javax.ws.rs.DELETE;
+import javax.ws.rs.DefaultValue;
 import javax.ws.rs.GET;
 import javax.ws.rs.PUT;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
+import javax.ws.rs.QueryParam;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 
@@ -73,6 +74,8 @@ public class Containers {
      *                      which the {@link PageModel} belongs.
      * @param pageModelName The name of the {@link PageModel} of which the
      *                      containers are retrieved.
+     * @param limit
+     * @param offset
      *
      * @return A JSON array containing the data of all {@link ContainerModel}s
      *         of the {@link PageModel} identified by {@code pageModelName} of
@@ -84,9 +87,11 @@ public class Containers {
     @Transactional(Transactional.TxType.REQUIRED)
     @AuthorizationRequired
     @RequiresPrivilege(CoreConstants.PRIVILEGE_ADMIN)
-    public JsonArray getContainers(
+    public ListView<ContainerModelDto> getContainers(
         @PathParam("appName") final String appName,
-        @PathParam("pageModelName") final String pageModelName
+        @PathParam("pageModelName") final String pageModelName,
+        @QueryParam("limit") @DefaultValue("20") final int limit,
+        @QueryParam("offset") @DefaultValue("0") final int offset
     ) {
         final CcmApplication app = controller.findCcmApplication(
             String.format("/%s/", appName)
@@ -96,14 +101,15 @@ public class Containers {
             app, pageModelName
         );
 
-        final JsonArrayBuilder arrayBuilder = Json.createArrayBuilder();
+        return new ListView<>(
-        pageModel
+            containerModelRepo
-            .getContainers()
+                .findContainersOfPageModelAsStream(pageModel, 0, 0)
-            .stream()
+                .map(model -> new ContainerModelDto(model))
-            .map(containerModel -> mapContainerModelToJson(containerModel))
+                .collect(Collectors.toList()),
-            .forEach(arrayBuilder::add);
+            containerModelRepo.countContainersOfPageModel(pageModel),
-
+            limit,
-        return arrayBuilder.build();
+            offset
+        );
     }
 
     /**
@@ -124,7 +130,7 @@ public class Containers {
     @Transactional(Transactional.TxType.REQUIRED)
     @AuthorizationRequired
     @RequiresPrivilege(CoreConstants.PRIVILEGE_ADMIN)
-    public JsonObject getContainer(
+    public ContainerModelDto getContainer(
         @PathParam("appName") final String appName,
         @PathParam("pageModelName") final String pageModelName,
         @PathParam("containerKey") final String containerKey
@@ -141,7 +147,7 @@ public class Containers {
             app, pageModel, containerKey
         );
 
-        return mapContainerModelToJson(container);
+        return new ContainerModelDto(container);
     }
 
     /**
@@ -176,7 +182,7 @@ public class Containers {
         @PathParam("appName") final String appName,
         @PathParam("pageModelName") final String pageModelName,
         @PathParam("containerKey") final String containerKey,
-        final JsonObject containerModelData
+        final ContainerModelDto containerModelData
     ) {
         final CcmApplication app = controller.findCcmApplication(
             String.format("/%s/", appName)
@@ -277,25 +283,4 @@ public class Containers {
             )
         ).build();
     }
-
-    /**
-     * Helper method for mapping a {@link ContainerModel} to JSON:
-     *
-     * @param containerModel The {@link ContainerModel} to map.
-     *
-     * @return A {@link JsonObject} containing the data of the
-     *         {@link ContainerModel}.
-     */
-    private JsonObject mapContainerModelToJson(
-        final ContainerModel containerModel) {
-
-        return Json
-            .createObjectBuilder()
-            .add("containerId", Long.toString(containerModel.getContainerId()))
-            .add("uuid", containerModel.getUuid())
-            .add("containerUuid", containerModel.getContainerUuid())
-            .add("key", containerModel.getKey())
-            .build();
-    }
-
 }

ccm-core/src/main/java/org/libreccm/api/pagemodels/dto/ContainerModelDto.java

@@ -45,6 +45,14 @@ public class ContainerModelDto {
         this.key = fromContainerModel.getKey();
     }
     
+    public long getContainerId() {
+        return containerId;
+    }
+    
+    public void setContainerId(final long containerId) {
+        this.containerId = containerId;
+    }
+    
     public String getUuid() {
         return uuid;
     }

ccm-core/src/main/java/org/libreccm/pagemodel/ContainerModel.java

@@ -59,10 +59,21 @@ import javax.xml.bind.annotation.XmlTransient;
 @Entity
 @Table(name = "PAGE_MODEL_CONTAINER_MODELS", schema = CoreConstants.DB_SCHEMA)
 @NamedQueries({
-    @NamedQuery(name = "ContainerModel.findByKeyAndPage",
+    @NamedQuery(
+        name = "ContainerModel.findContainersOfPageModel",
+        query = "SELECT c FROM ContainerModel c WHERE c.pageModel = :pageModel"
+    ),
+    @NamedQuery(
+        name = "ContainerModel.countContainersOfPageModel",
+        query = "SELECT COUNT(c) FROM ContainerModel c "
+                    + "WHERE c.pageModel = :pageModel"
+    ),
+    @NamedQuery(
+        name = "ContainerModel.findByKeyAndPage",
         query = "SELECT c FROM ContainerModel c "
                     + "WHERE c.key = :key "
-                            + "AND c.pageModel = :pageModel")
+                    + "AND c.pageModel = :pageModel"
+    )
 })
 @XmlRootElement(name = "container-model")
 public class ContainerModel implements Serializable {

ccm-core/src/main/java/org/libreccm/pagemodel/ContainerModelRepository.java

@@ -23,8 +23,10 @@ import org.libreccm.core.CoreConstants;
 import org.libreccm.security.AuthorizationRequired;
 import org.libreccm.security.RequiresPrivilege;
 
+import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
+import java.util.stream.Stream;
 
 import javax.enterprise.context.RequestScoped;
 import javax.persistence.NoResultException;
@@ -83,6 +85,53 @@ public class ContainerModelRepository
         }
     }
 
+    @Transactional(Transactional.TxType.REQUIRED)
+    public List<ContainerModel> findContainersOfPageModelAsList(
+        final PageModel pageModel,
+        final int limit,
+        final int offset
+    ) {
+        return getEntityManager()
+            .createNamedQuery(
+                "ContainerModel.findContainersOfPageModel",
+                ContainerModel.class
+            )
+            .setParameter("pageModel", pageModel)
+            .setMaxResults(limit)
+            .setFirstResult(offset)
+            .getResultList();
+    }
+
+    @Transactional(Transactional.TxType.REQUIRED)
+    public Stream<ContainerModel> findContainersOfPageModelAsStream(
+        final PageModel pageModel,
+        final int limit,
+        final int offset
+    ) {
+        return getEntityManager()
+            .createNamedQuery(
+                "ContainerModel.findContainersOfPageModel",
+                ContainerModel.class
+            )
+            .setParameter("pageModel", pageModel)
+            .setMaxResults(limit)
+            .setFirstResult(offset)
+            .getResultStream();
+    }
+
+    @Transactional(Transactional.TxType.REQUIRED)
+    public long countContainersOfPageModel(
+        final PageModel pageModel
+    ) {
+        return getEntityManager()
+            .createNamedQuery(
+                "ContainerModel.countContainersOfPageModel",
+                Long.class
+            )
+            .setParameter("pageModel", pageModel)
+            .getSingleResult();
+    }
+
     @Transactional(Transactional.TxType.REQUIRED)
     public Optional<ContainerModel> findContainerByKeyAndPageModel(
         final String key, final PageModel pageModel) {