Java tutorial
/* * Copyright 2010-2014 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"). * You may not use this file except in compliance with the License. * A copy of the License is located at * * http://aws.amazon.com/apache2.0 * * or in the "license" file accompanying this file. This file 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.amazonaws.http.conn; import java.lang.reflect.InvocationHandler; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.lang.reflect.Proxy; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.conn.ClientConnectionRequest; import com.amazonaws.metrics.AwsSdkMetrics; import com.amazonaws.metrics.ServiceLatencyProvider; import com.amazonaws.util.AWSServiceMetrics; class ClientConnectionRequestFactory { private static final Log log = LogFactory.getLog(ClientConnectionRequestFactory.class); private static final Class<?>[] interfaces = { ClientConnectionRequest.class, Wrapped.class }; /** * Returns a wrapped instance of {@link ClientConnectionRequest} * to capture the necessary performance metrics. * @param orig the target instance to be wrapped */ static ClientConnectionRequest wrap(ClientConnectionRequest orig) { if (orig instanceof Wrapped) throw new IllegalArgumentException(); return (ClientConnectionRequest) Proxy.newProxyInstance( // https://github.com/aws/aws-sdk-java/pull/48#issuecomment-29454423 ClientConnectionRequestFactory.class.getClassLoader(), interfaces, new Handler(orig)); } /** * The handler behind the dynamic proxy for {@link ClientConnectionRequest} * so that the latency of the * {@link ClientConnectionRequest#getConnection(long, java.util.concurrent.TimeUnit)} * can be captured. */ private static class Handler implements InvocationHandler { private final ClientConnectionRequest orig; Handler(ClientConnectionRequest orig) { this.orig = orig; } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { try { if ("getConnection".equals(method.getName())) { ServiceLatencyProvider latencyProvider = new ServiceLatencyProvider( AWSServiceMetrics.HttpClientGetConnectionTime); try { return method.invoke(orig, args); } finally { AwsSdkMetrics.getServiceMetricCollector().collectLatency(latencyProvider.endTiming()); } } return method.invoke(orig, args); } catch (InvocationTargetException e) { log.debug("", e); throw e.getCause(); } } } }