From: erik Date: Sat, 17 Jul 2010 20:31:56 +0000 (+0000) Subject: (no commit message) X-Git-Tag: wamblee-utils-0.3~27 X-Git-Url: http://wamblee.org/gitweb/?a=commitdiff_plain;h=e166aef739852408410043333880c2392f925f80;p=utils --- diff --git a/support/general/src/main/java/org/wamblee/general/ThreadSpecificProxyFactory.java b/support/general/src/main/java/org/wamblee/general/ThreadSpecificProxyFactory.java new file mode 100644 index 00000000..f7087296 --- /dev/null +++ b/support/general/src/main/java/org/wamblee/general/ThreadSpecificProxyFactory.java @@ -0,0 +1,112 @@ +/* + * 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.general; + +import java.lang.reflect.InvocationHandler; +import java.lang.reflect.InvocationTargetException; +import java.lang.reflect.Method; +import java.lang.reflect.Proxy; + +/** + * Thread-specific proxy is used to create implementations of interfaces that + * delegate to a thread-specific implementation of the service. + * + * It is used for instance to pass a transaction scoped entity manager around. + * + * The {@link #set(Object)} method sets the current service instance for the current thread. + * The {@link #get()} method gets the current service instance for the current thread. + * The {@link #getProxy()} method gets a proxy that will delegate at runtime to the thread-specific + * instance. The result from this method can be passed at construction of an object that will be used + * by multiple threads. + * + * This class is mostly used by other test tools. + * + * @param T + * Interface to proxy. + * @author Erik Brakkee + * + */ +public class ThreadSpecificProxyFactory { + private class ThreadSpecificInvocationHandler implements InvocationHandler { + + @Override + public Object invoke(Object aProxy, Method aMethod, Object[] aArgs) + throws Throwable { + try { + return aMethod.invoke(svc.get(), aArgs); + } catch (InvocationTargetException e) { + throw e.getCause(); + } + } + } + + private ThreadLocal svc = new ThreadLocal(); + private Class clazz; + + /** + * Constructs the factory. + * + * @param aClass + * Interface class of the service to proxy. + */ + public ThreadSpecificProxyFactory(Class aClass) { + if (!aClass.isInterface()) { + throw new IllegalArgumentException("Class " + aClass.getName() + + " is not an interface"); + } + clazz = aClass; + } + + /** + * Sets the thread-specific service. + * + * @param aService + * Service, use null value to reset. + */ + public void set(T aService) { + svc.set(aService); + } + + /** + * Gets the current thread-specific service. + * @return Service. + */ + public T get() { + return svc.get(); + } + + /** + * Gets the proxy that delegates to the thread-specific instance set by + * {@link #set(Object)} + * + * @return Proxy. + */ + public T getProxy() { + InvocationHandler handler = new ThreadSpecificInvocationHandler(); + 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); + } + } +} diff --git a/support/general/src/test/java/org/wamblee/general/ThreadSpecificProxyFactoryTest.java b/support/general/src/test/java/org/wamblee/general/ThreadSpecificProxyFactoryTest.java new file mode 100644 index 00000000..310e47a7 --- /dev/null +++ b/support/general/src/test/java/org/wamblee/general/ThreadSpecificProxyFactoryTest.java @@ -0,0 +1,107 @@ +/* + * 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.general; + +import static junit.framework.Assert.*; +import static org.mockito.Matchers.*; +import static org.mockito.Mockito.*; + +import org.junit.After; +import org.junit.Before; +import org.junit.Test; +import org.wamblee.general.ThreadSpecificProxyFactory; + +public class ThreadSpecificProxyFactoryTest { + + private static interface Service { + int execute(int aX) throws Exception; + } + + private ThreadSpecificProxyFactory factory; + private Service proxy; + + @Before + public void setUp() { + factory = new ThreadSpecificProxyFactory(Service.class); + proxy = factory.getProxy(); + } + + @After + public void tearDown() { + // Empty. + } + + @Test(expected = NullPointerException.class) + public void testNoSvcDefined() throws Exception { + proxy.execute(10); + } + + @Test + public void testInvokeThroughProxy() throws Exception { + Service svc = mock(Service.class); + when(svc.execute(anyInt())).thenReturn(50); + factory.set(svc); + assertEquals(50, proxy.execute(10)); + verify(svc).execute(10); + } + + @Test + public void testInvokeThroughProxyWithException() throws Exception { + Service svc = mock(Service.class); + try { + when(svc.execute(anyInt())).thenThrow( + new RuntimeException("exception thrown")); + factory.set(svc); + svc.execute(10); + fail(); + } catch (RuntimeException e) { + assertEquals("exception thrown", e.getMessage()); + } + } + + private int returnFromThread; + + @Test + public void testVerifyThreadSpecificUsingTwoThreads() throws Exception { + Service svc1 = mock(Service.class); + final Service svc2 = mock(Service.class); + when(svc1.execute(anyInt())).thenReturn(10); + when(svc2.execute(anyInt())).thenReturn(20); + + factory.set(svc1); + assertEquals(10, svc1.execute(10)); + Thread t = new Thread() { + public void run() { + factory.set(svc2); + try { + returnFromThread = proxy.execute(100); + } catch (Exception e) { + returnFromThread = 100000; + } + }; + }; + t.start(); + t.join(); + assertEquals(20, returnFromThread); + assertEquals(10, proxy.execute(100)); + + } + + @Test(expected = IllegalArgumentException.class) + public void testNotAnInterface() { + ThreadSpecificProxyFactory f = new ThreadSpecificProxyFactory(String.class); + } +}