Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.synapse.transport.utils.logging; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.HttpException; import org.apache.http.HttpResponse; import org.apache.http.nio.ContentDecoder; import org.apache.http.nio.ContentEncoder; import org.apache.http.nio.NHttpClientConnection; import org.apache.http.nio.NHttpClientEventHandler; import java.io.IOException; /** * A decorator (wrapper) for NHttpClientEventHandler instances. This decorator * logs additional debug information regarding each of the events triggered on the * actual NHttpClientEventHandler instance. Most events are logged 'before' they are * dispatched to the wrapped NHttpClientEventHandler, but this implementation does * not modify the event arguments by any means. In that sense this decorator is * read-only and safe. This implementation does not log the exception event. It is * expected that the actual NHttpClientEventHandler will take the necessary steps to * log exceptions. */ public class LoggingClientEventHandler implements NHttpClientEventHandler { private final Log log; private final NHttpClientEventHandler handler; /** * Create a new instance of the decorator. * * @param handler The instance of NHttpClientEventHandler to be decorated (wrapped) */ public LoggingClientEventHandler(final NHttpClientEventHandler handler) { if (handler == null) { throw new IllegalArgumentException("HTTP client handler must not be null"); } this.handler = handler; this.log = LogFactory.getLog(handler.getClass()); } public void connected(final NHttpClientConnection conn, final Object attachment) throws IOException, HttpException { if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + ": Connected (" + attachment + ")"); } this.handler.connected(conn, attachment); } public void closed(final NHttpClientConnection conn) { if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + ": Closed"); } this.handler.closed(conn); } public void endOfInput(NHttpClientConnection conn) throws IOException { if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + ": Closed at remote end"); } this.handler.endOfInput(conn); } public void exception(NHttpClientConnection conn, Exception ex) { // Do not log errors at this level - Actual handler implementation should do that this.handler.exception(conn, ex); } public void requestReady(final NHttpClientConnection conn) throws IOException, HttpException { if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + ": InRequest ready"); } this.handler.requestReady(conn); } public void outputReady(final NHttpClientConnection conn, final ContentEncoder encoder) throws IOException, HttpException { if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + ": Output ready"); } this.handler.outputReady(conn, encoder); if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + ": Content encoder " + encoder); } } public void responseReceived(final NHttpClientConnection conn) throws IOException, HttpException { HttpResponse response = conn.getHttpResponse(); if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + " : " + response.getStatusLine()); } this.handler.responseReceived(conn); } public void inputReady(final NHttpClientConnection conn, final ContentDecoder decoder) throws IOException, HttpException { if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + ": Input ready"); } this.handler.inputReady(conn, decoder); if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + ": Content decoder " + decoder); } } public void timeout(final NHttpClientConnection conn) throws IOException, HttpException { if (this.log.isDebugEnabled()) { this.log.debug("HTTP connection " + conn + ": Timeout"); } this.handler.timeout(conn); } }