Added process diagram REST resource (ACT-959)

modules/activiti-webapp-rest2/src/main/java/org/activiti/rest/api/process/ProcessDefinitionDiagramResource.java

+package org.activiti.rest.api.process;
+
+import java.io.InputStream;
+
+import org.activiti.engine.ActivitiException;
+import org.activiti.engine.RepositoryService;
+import org.activiti.engine.repository.ProcessDefinition;
+import org.activiti.rest.api.ActivitiUtil;
+import org.activiti.rest.api.SecuredResource;
+import org.restlet.data.MediaType;
+import org.restlet.representation.InputRepresentation;
+import org.restlet.resource.Get;
+
+public class ProcessDefinitionDiagramResource extends SecuredResource {
+
+	@Get
+	public InputRepresentation getDiagram() {
+		if (authenticate() == false)
+			return null;
+
+		String processDefinitionId = (String) getRequest().getAttributes().get("processDefinitionId");
+
+		if (processDefinitionId == null) {
+			throw new ActivitiException("No process definition id provided");
+		}
+
+		RepositoryService repositoryService = ActivitiUtil.getRepositoryService();
+		ProcessDefinition processDefinition = repositoryService.createProcessDefinitionQuery()
+		    .processDefinitionId(processDefinitionId).singleResult();
+
+		if (processDefinition == null) {
+			throw new ActivitiException("Process definition " + processDefinitionId + " could not be found");
+		}
+
+		if (processDefinition.getDiagramResourceName() == null) {
+			throw new ActivitiException("Diagram resource could not be found");
+		}
+		final InputStream definitionImageStream = repositoryService.getResourceAsStream(
+		    processDefinition.getDeploymentId(), processDefinition.getDiagramResourceName());
+
+		if (definitionImageStream == null) {
+			throw new ActivitiException("Diagram resource could not be found");
+		}
+		return new InputRepresentation(definitionImageStream, MediaType.IMAGE_PNG);
+	}
+
+}

modules/activiti-webapp-rest2/src/main/java/org/activiti/rest/application/ActivitiRestApplication.java

@@ -34,6 +34,7 @@ import org.activiti.rest.api.management.JobsResource;
 import org.activiti.rest.api.management.TableDataResource;
 import org.activiti.rest.api.management.TableResource;
 import org.activiti.rest.api.management.TablesResource;
+import org.activiti.rest.api.process.ProcessDefinitionDiagramResource;
 import org.activiti.rest.api.process.ProcessDefinitionFormResource;
 import org.activiti.rest.api.process.ProcessDefinitionPropertiesResource;
 import org.activiti.rest.api.process.ProcessDefinitionsResource;
@@ -128,6 +129,7 @@ public class ActivitiRestApplication extends Application {
     router.attach("/processInstance/{processInstanceId}", ProcessInstanceResource.class);
     router.attach("/processInstance/{processInstanceId}/diagram", ProcessInstanceDiagramResource.class);
     router.attach("/process-definition/{processDefinitionId}/form", ProcessDefinitionFormResource.class);
+    router.attach("/process-definition/{processDefinitionId}/diagram", ProcessDefinitionDiagramResource.class);
     router.attach("/process-definition/{processDefinitionId}/properties", ProcessDefinitionPropertiesResource.class);
     
     router.attach("/tasks", TasksResource.class);