| /** |
| * Copyright (C) 2010 Google, Inc. |
| * |
| * 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 com.google.inject.persist.jpa; |
| |
| import com.google.inject.Inject; |
| import com.google.inject.Singleton; |
| import com.google.common.collect.Lists; |
| import com.google.common.base.Preconditions; |
| import com.google.inject.persist.PersistModule; |
| import com.google.inject.persist.PersistService; |
| import com.google.inject.persist.UnitOfWork; |
| import com.google.inject.persist.finder.DynamicFinder; |
| import com.google.inject.persist.finder.Finder; |
| import com.google.inject.util.Providers; |
| import java.lang.reflect.AccessibleObject; |
| import java.lang.reflect.InvocationHandler; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Proxy; |
| import java.util.List; |
| import java.util.Properties; |
| import javax.persistence.EntityManager; |
| import javax.persistence.EntityManagerFactory; |
| import org.aopalliance.intercept.MethodInterceptor; |
| import org.aopalliance.intercept.MethodInvocation; |
| |
| /** |
| * JPA provider for guice persist. |
| * |
| * @author dhanji@gmail.com (Dhanji R. Prasanna) |
| */ |
| public final class JpaPersistModule extends PersistModule { |
| private final String jpaUnit; |
| |
| public JpaPersistModule(String jpaUnit) { |
| Preconditions.checkArgument(null != jpaUnit && jpaUnit.length() > 0, |
| "JPA unit name must be a non-empty string."); |
| this.jpaUnit = jpaUnit; |
| } |
| |
| private Properties properties; |
| private MethodInterceptor transactionInterceptor; |
| |
| @Override protected void configurePersistence() { |
| bindConstant().annotatedWith(Jpa.class).to(jpaUnit); |
| |
| if (null != properties) { |
| bind(Properties.class).annotatedWith(Jpa.class).toInstance(properties); |
| } else { |
| bind(Properties.class).annotatedWith(Jpa.class) |
| .toProvider(Providers.<Properties>of(null)); |
| } |
| |
| bind(JpaPersistService.class).in(Singleton.class); |
| |
| bind(PersistService.class).to(JpaPersistService.class); |
| bind(UnitOfWork.class).to(JpaPersistService.class); |
| bind(EntityManager.class).toProvider(JpaPersistService.class); |
| bind(EntityManagerFactory.class) |
| .toProvider(JpaPersistService.EntityManagerFactoryProvider.class); |
| |
| transactionInterceptor = new JpaLocalTxnInterceptor(); |
| requestInjection(transactionInterceptor); |
| |
| // Bind dynamic finders. |
| for (Class<?> finder : dynamicFinders) { |
| bindFinder(finder); |
| } |
| } |
| |
| @Override protected MethodInterceptor getTransactionInterceptor() { |
| return transactionInterceptor; |
| } |
| |
| /** |
| * Configures the JPA persistence provider with a set of properties. |
| * |
| * @param properties A set of name value pairs that configure a JPA persistence |
| * provider as per the specification. |
| */ |
| public JpaPersistModule properties(Properties properties) { |
| this.properties = properties; |
| return this; |
| } |
| |
| private final List<Class<?>> dynamicFinders = Lists.newArrayList(); |
| |
| /** |
| * Adds an interface to this module to use as a dynamic finder. |
| * |
| * @param iface Any interface type whose methods are all dynamic finders. |
| */ |
| public <T> JpaPersistModule addFinder(Class<T> iface) { |
| dynamicFinders.add(iface); |
| return this; |
| } |
| |
| private <T> void bindFinder(Class<T> iface) { |
| if (!isDynamicFinderValid(iface)) { |
| return; |
| } |
| |
| InvocationHandler finderInvoker = new InvocationHandler() { |
| @Inject JpaFinderProxy finderProxy; |
| |
| public Object invoke(final Object thisObject, final Method method, final Object[] args) |
| throws Throwable { |
| |
| // Don't intercept non-finder methods like equals and hashcode. |
| if (!method.isAnnotationPresent(Finder.class)) { |
| // NOTE(user): This is not ideal, we are using the invocation handler's equals |
| // and hashcode as a proxy (!) for the proxy's equals and hashcode. |
| return method.invoke(this, args); |
| } |
| |
| return finderProxy.invoke(new MethodInvocation() { |
| public Method getMethod() { |
| return method; |
| } |
| |
| public Object[] getArguments() { |
| return null == args ? new Object[0] : args; |
| } |
| |
| public Object proceed() throws Throwable { |
| return method.invoke(thisObject, args); |
| } |
| |
| public Object getThis() { |
| throw new UnsupportedOperationException("Bottomless proxies don't expose a this."); |
| } |
| |
| public AccessibleObject getStaticPart() { |
| throw new UnsupportedOperationException(); |
| } |
| }); |
| } |
| }; |
| requestInjection(finderInvoker); |
| |
| @SuppressWarnings("unchecked") // Proxy must produce instance of type given. |
| T proxy = (T) Proxy |
| .newProxyInstance(Thread.currentThread().getContextClassLoader(), new Class<?>[] { iface }, |
| finderInvoker); |
| |
| bind(iface).toInstance(proxy); |
| } |
| |
| private boolean isDynamicFinderValid(Class<?> iface) { |
| boolean valid = true; |
| if (!iface.isInterface()) { |
| addError(iface + " is not an interface. Dynamic Finders must be interfaces."); |
| valid = false; |
| } |
| |
| for (Method method : iface.getMethods()) { |
| DynamicFinder finder = DynamicFinder.from(method); |
| if (null == finder) { |
| addError("Dynamic Finder methods must be annotated with @Finder, but " + iface |
| + "." + method.getName() + " was not"); |
| valid = false; |
| } |
| } |
| return valid; |
| } |
| } |