+++ /dev/null
-/*
- * Copyright 2005-2010 the original author or authors.
- *
- * Licensed 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.wamblee.test.persistence;
-
-
-import java.lang.reflect.InvocationHandler;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.lang.reflect.Proxy;
-
-import javax.persistence.EntityManager;
-
-import org.wamblee.test.persistence.JpaBuilder.JpaUnitOfWork;
-import org.wamblee.test.transactions.ThreadSpecificProxyFactory;
-
-/**
- * This utility makes sure that each invocation on a certain interface is
- * carried out within a JPA unit of work. Note that this is equivalent
- * to the sementics of a requiresNew transaction attribute.
- *
- * Use {@link #getTransactionScopedEntityManager()} to get the transaction
- * scoped entity manager to pass to services.
- *
- *
- * For example:
- * <pre>
- * JpaBuilder builder = ...
- * TransactionProxyFactory<Service> factory = new TransactionProxyFactory<Service>(
- * builder, Service.class);
- * Service service = new JpaService(factory.getTransactionScopedEntityManager());
- * Service proxy = factory.getProxy(service);
- * proxy.executeMethod(...);
- * </pre>
- * The above example executes the executeMethod() call on the service object within an active transaction.
- * In the constructor of the service a transaction scoped entity manager is passed.
- *
- * @param T
- * Type of interface to proxy.
- *
- * @author Erik Brakkee
- */
-public class TransactionProxyFactory<T> {
-
- /**
- * Executes the call on the service within a new transaction.
- *
- * @author Erik Brakkee
- *
- * @param <T> Type of the service interface.
- */
- private class UnitOfWorkInvocationHandler<T> implements InvocationHandler {
-
- private T service;
-
- public UnitOfWorkInvocationHandler(T aService) {
- service = aService;
- }
-
- @Override
- public Object invoke(Object aProxy, final Method aMethod,
- final Object[] aArgs) throws Throwable {
- return TransactionProxyFactory.this.jpaBuilder
- .execute(new JpaUnitOfWork<Object>() {
- @Override
- public Object execute(EntityManager aEm) throws Exception {
- EntityManager oldEm = ENTITY_MANAGER.get();
- try {
- ENTITY_MANAGER.set(aEm);
- return aMethod.invoke(service, aArgs);
- } catch (InvocationTargetException e) {
- Throwable cause = e.getCause();
- if (cause instanceof Exception) {
- throw (Exception) cause;
- } else if (cause instanceof Error) {
- throw (Error) cause;
- }
- // last resort.
- throw new RuntimeException(e);
- } finally {
- ENTITY_MANAGER.set(oldEm);
- }
- }
- });
- }
-
- }
-
- private static final ThreadSpecificProxyFactory<EntityManager> ENTITY_MANAGER = new ThreadSpecificProxyFactory<EntityManager>(
- EntityManager.class);
-
- private JpaBuilder jpaBuilder;
- private Class<T> clazz;
-
- /**
- * Constructs the transaction proxy.
- *
- * @param aJpaBuilder
- */
- public TransactionProxyFactory(JpaBuilder aJpaBuilder, Class<T> aClass) {
- jpaBuilder = aJpaBuilder;
- clazz = aClass;
- }
-
- public EntityManager getTransactionScopedEntityManager() {
- return ENTITY_MANAGER.getProxy();
- }
-
- public T getProxy(T aService) {
- InvocationHandler handler = new UnitOfWorkInvocationHandler<T>(aService);
- Class proxyClass = Proxy.getProxyClass(clazz.getClassLoader(),
- new Class[] { clazz });
- T proxy;
- try {
- proxy = (T) proxyClass.getConstructor(
- new Class[] { InvocationHandler.class }).newInstance(
- new Object[] { handler });
- return proxy;
- } catch (Exception e) {
- throw new RuntimeException("Could not create proxy for " +
- clazz.getName(), e);
- }
- }
-}