Java tutorial
/** * The software subject to this notice and license includes both human readable * source code form and machine readable, binary, object code form. The nci-commons * Software was developed in conjunction with the National Cancer Institute * (NCI) by NCI employees and 5AM Solutions, Inc. (5AM). To the extent * government employees are authors, any rights in such works shall be subject * to Title 17 of the United States Code, section 105. * * This nci-commons Software License (the License) is between NCI and You. You (or * Your) shall mean a person or an entity, and all other entities that control, * are controlled by, or are under common control with the entity. 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This License is granted at no charge to You. * * Your redistributions of the source code for the Software must retain the * above copyright notice, this list of conditions and the disclaimer and * limitation of liability of Article 6, below. Your redistributions in object * code form must reproduce the above copyright notice, this list of conditions * and the disclaimer of Article 6 in the documentation and/or other materials * provided with the distribution, if any. * * Your end-user documentation included with the redistribution, if any, must * include the following acknowledgment: This product includes software * developed by 5AM and the National Cancer Institute. If You do not include * such end-user documentation, You shall include this acknowledgment in the * Software itself, wherever such third-party acknowledgments normally appear. * * You may not use the names "The National Cancer Institute", "NCI", or "5AM" * to endorse or promote products derived from this Software. 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In the event that You fail to obtain such permissions, You agree * to indemnify NCI for any claims against NCI by such third parties, except to * the extent prohibited by law, resulting from Your failure to obtain such * permissions. * * For sake of clarity, and not by way of limitation, You may add Your own * copyright statement to Your modifications and to the derivative works, and * You may provide additional or different license terms and conditions in Your * sublicenses of modifications of the Software, or any derivative works of the * Software as a whole, provided Your use, reproduction, and distribution of the * Work otherwise complies with the conditions stated in this License. * * THIS SOFTWARE IS PROVIDED "AS IS," AND ANY EXPRESSED OR IMPLIED WARRANTIES, * (INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, * NON-INFRINGEMENT AND FITNESS FOR A PARTICULAR PURPOSE) ARE DISCLAIMED. IN NO * EVENT SHALL THE NATIONAL CANCER INSTITUTE, 5AM SOLUTIONS, INC. OR THEIR * AFFILIATES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package gov.nih.nci.firebird.proxy; import com.google.inject.Provider; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Proxy; import java.util.ArrayList; import java.util.List; import org.apache.commons.pool.ObjectPool; import org.apache.commons.pool.PoolableObjectFactory; import org.apache.commons.pool.impl.StackObjectPool; import org.junit.After; import org.junit.Test; import org.mockito.invocation.InvocationOnMock; import org.mockito.stubbing.Answer; import static org.junit.Assert.*; import static org.mockito.Mockito.*; /** * test PoolingHandler */ public class PoolingHandlerTest { private final static List<Thread> threads = new ArrayList<Thread>(5); @After public void resetThreads() throws InterruptedException { threads.clear(); synchronized (BaseClient.class) { BaseClient.class.notifyAll(); } for (Thread t : threads) { t.join(); } } @Test public void testProvider() { @SuppressWarnings("unchecked") Provider<ITestClient> provider = mock(Provider.class); when(provider.get()).thenAnswer(new Answer<ITestClient>() { @Override public ITestClient answer(InvocationOnMock invocation) throws Throwable { return makeBaseMockClient(); } }); InvocationHandler handler = new PoolingHandler(provider, 3, 3); ITestClient proxy = (ITestClient) Proxy.newProxyInstance(this.getClass().getClassLoader(), new Class<?>[] { ITestClient.class }, handler); proxy.doSomethingUseful(null); verify(provider, times(1)).get(); } @Test @SuppressWarnings("unchecked") public void testNormalInvocation() throws Exception { final ITestClient rootMock = makeBaseMockClient(); PoolableObjectFactory<Object> factory = mock(PoolableObjectFactory.class); when(factory.validateObject(any())).thenReturn(Boolean.TRUE); when(factory.makeObject()).thenAnswer(new Answer<ITestClient>() { @Override public ITestClient answer(InvocationOnMock invocation) throws Throwable { return new RelayClient(rootMock); } }); ITestClient proxy = newProxy(factory); assertEquals(1, proxy.doSomethingUseful("foo")); try { proxy.doSomethingBad(1); fail(); } catch (IllegalArgumentException e) { // expected } try { proxy.doSomethingWorse(false); fail(); } catch (UnsupportedOperationException e) { // expected } verify(rootMock).doSomethingUseful("foo"); verify(rootMock).doSomethingBad(1); verify(rootMock).doSomethingWorse(false); verifyNoMoreInteractions(rootMock); } @Test public void testPoolUse() throws Exception { PoolableObjectFactory<Object> factory = makeMockFactory(); ObjectPool<Object> pool = spy(new StackObjectPool<Object>(factory)); InvocationHandler handler = new PoolingHandler(pool); ITestClient proxy = (ITestClient) Proxy.newProxyInstance(this.getClass().getClassLoader(), new Class<?>[] { ITestClient.class }, handler); proxy.doSomethingUseful(null); verify(pool, times(1)).borrowObject(); verify(pool, times(1)).returnObject(any()); } @Test public void testExpectedSuperExceptionHandeling() throws Exception { PoolableObjectFactory<Object> factory = makeMockFactory(); ObjectPool<Object> pool = spy(new StackObjectPool<Object>(factory)); PoolingHandler handler = new PoolingHandler(pool); handler.getValidExceptions().add(RuntimeException.class); assertTrue(new IllegalArgumentException() instanceof RuntimeException); ITestClient proxy = (ITestClient) Proxy.newProxyInstance(this.getClass().getClassLoader(), new Class<?>[] { ITestClient.class }, handler); try { proxy.doSomethingBad(0); fail(); } catch (IllegalArgumentException ex) { } verify(pool, times(1)).borrowObject(); verify(pool, times(1)).returnObject(any()); verify(factory, times(0)).destroyObject(any()); } @Test public void testExpectedSubExceptionHandling() throws Exception { PoolableObjectFactory<Object> factory = makeMockFactory(); ObjectPool<Object> pool = spy(new StackObjectPool<Object>(factory)); PoolingHandler handler = new PoolingHandler(pool); class SubException extends IllegalArgumentException { private static final long serialVersionUID = 1L; } handler.getValidExceptions().add(SubException.class); ITestClient proxy = (ITestClient) Proxy.newProxyInstance(this.getClass().getClassLoader(), new Class<?>[] { ITestClient.class }, handler); try { proxy.doSomethingBad(0); fail(); } catch (IllegalArgumentException ex) { } verify(pool, times(1)).borrowObject(); verify(pool, times(0)).returnObject(any()); verify(factory, times(1)).destroyObject(any()); } @Test public void testPoolDepletion() throws InterruptedException { Provider<BaseClient> provider = new Provider<BaseClient>() { @Override public BaseClient get() { return new BaseClient(); } }; PoolingHandler handler = new PoolingHandler(provider, 3, 0); final ITestClient proxy = (ITestClient) Proxy.newProxyInstance(this.getClass().getClassLoader(), new Class<?>[] { ITestClient.class }, handler); for (int i = 0; i < 5; i++) { Thread t = new Thread() { @Override public void run() { proxy.block(); } }; t.start(); } synchronized (threads) { while (threads.size() < 5) { threads.wait(500L); } } // all threads started assertEquals(0, handler.getPool().getNumIdle()); assertEquals(5, handler.getPool().getNumActive()); // let threads resume. synchronized (BaseClient.class) { BaseClient.class.notifyAll(); } for (Thread t : threads) { t.join(); } assertEquals(3, handler.getPool().getNumIdle()); } @SuppressWarnings("unchecked") private PoolableObjectFactory<Object> makeMockFactory() { PoolableObjectFactory<Object> factory = mock(PoolableObjectFactory.class); when(factory.validateObject(any())).thenReturn(Boolean.TRUE); try { when(factory.makeObject()).thenAnswer(new Answer<ITestClient>() { @Override public ITestClient answer(InvocationOnMock invocation) throws Throwable { return makeBaseMockClient(); } }); } catch (Exception e) { //will never happen here. } return factory; } private ITestClient newProxy(PoolableObjectFactory<Object> factory) { PoolingHandler handler = new PoolingHandler(factory, 5, 1); handler.getValidExceptions().add(IllegalArgumentException.class); return (ITestClient) Proxy.newProxyInstance(this.getClass().getClassLoader(), new Class<?>[] { ITestClient.class }, handler); } private ITestClient makeBaseMockClient() { return spy(new BaseClient()); } public static interface ITestClient { int doSomethingUseful(String param); void doSomethingBad(int param) throws IllegalArgumentException; void doSomethingWorse(boolean param); void block(); } private static class BaseClient implements ITestClient { @Override public int doSomethingUseful(String param) { return 1; } @Override public void doSomethingBad(int param) throws IllegalArgumentException { throw new IllegalArgumentException(); } @Override public void doSomethingWorse(boolean param) { throw new UnsupportedOperationException(); } @Override public void block() { try { synchronized (BaseClient.class) { synchronized (threads) { threads.add(Thread.currentThread()); threads.notify(); } BaseClient.class.wait(); } } catch (InterruptedException e) { e.printStackTrace(); } } } private static class RelayClient implements ITestClient { private final ITestClient target; public RelayClient(ITestClient target) { this.target = target; } @Override public int doSomethingUseful(String param) { return target.doSomethingUseful(param); } @Override public void doSomethingBad(int param) throws IllegalArgumentException { target.doSomethingBad(param); } @Override public void doSomethingWorse(boolean param) { target.doSomethingWorse(param); } @Override public void block() { target.block(); } } }