1 files changed, 86 insertions, 0 deletions
diff --git a/sandbox/old/contrib/persistence/common/src/main/java/org/apache/tuscany/service/persistence/common/EntityManagerProxy.java b/sandbox/old/contrib/persistence/common/src/main/java/org/apache/tuscany/service/persistence/common/EntityManagerProxy.java
new file mode 100644
index 0000000000..492bd36689
--- /dev/null
+++ b/sandbox/old/contrib/persistence/common/src/main/java/org/apache/tuscany/service/persistence/common/EntityManagerProxy.java
@@ -0,0 +1,86 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tuscany.service.persistence.common;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.util.Properties;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.transaction.Synchronization;
+import javax.transaction.Transaction;
+import javax.transaction.TransactionManager;
+
+/**
+ * Proxy for entity manager.
+ *
+ * @version $Rev$ $Date$
+ */
+public class EntityManagerProxy implements InvocationHandler {
+    
+    // Thread local cache of entity managers
+    private ThreadLocal<EntityManager> entityManagers = new ThreadLocal<EntityManager>();
+
+    // Properties
+    private Properties prop;
+    
+    // Entity manager factory
+    private EntityManagerFactory emf;
+    
+    // Transaction manager
+    private TransactionManager txm;
+    
+    /**
+     * Initializes the artifacts required to create an EM.
+     * 
+     * @param prop EM creation porperty overrides.
+     * @param emf Entity manager factory to use.
+     * @param txm Transaction manager to use.
+     */
+    public EntityManagerProxy(Properties prop, EntityManagerFactory emf, TransactionManager txm) {
+        this.prop = prop;
+        this.txm = txm;
+        this.emf = emf;
+    }
+    
+    /**
+     * Proxies the entity manager.
+     */
+    public Object invoke(Object target, Method method, Object[] parameters) throws Throwable {
+        
+        EntityManager entityManager = entityManagers.get();
+        if(entityManager != null) {
+            entityManager = emf.createEntityManager(prop);
+            entityManagers.set(entityManager);
+            Transaction tx = txm.getTransaction();
+            if(tx != null) {
+                tx.registerSynchronization(new Synchronization() {
+                    public void afterCompletion(int arg0) {
+                        entityManagers.set(null);
+                    }
+                    public void beforeCompletion() {
+                    }
+                });
+            }
+        }
+        return method.invoke(entityManager, parameters);
+    }
+
+}