# LoggingNHttpServiceHandler.java

    /*
     *  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.http.conn;

    import java.io.IOException;

    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.apache.http.ConnectionClosedException;
    import org.apache.http.HttpException;
    import org.apache.http.HttpRequest;
    import org.apache.http.nio.ContentDecoder;
    import org.apache.http.nio.ContentEncoder;
    import org.apache.http.nio.NHttpServerConnection;
    import org.apache.http.nio.NHttpServerEventHandler;
    /**
     * Decorator class intended to transparently extend an {@link NHttpServerEventHandler}
     * with basic event logging capabilities using Commons Logging.
     */
    class LoggingNHttpServiceHandler implements NHttpServerEventHandler {

        private final Log log;
        private final NHttpServerEventHandler handler;

        public LoggingNHttpServiceHandler(
                final Log log,
                final NHttpServerEventHandler handler) {
            super();
            if (handler == null) {
                throw new IllegalArgumentException("HTTP service handler may not be null");
            }
            this.handler = handler;
            this.log = LogFactory.getLog(handler.getClass());
        }

        public void connected(
                final NHttpServerConnection conn) throws IOException, HttpException {
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": Connected");
            }
            this.handler.connected(conn);
        }

        public void closed(final NHttpServerConnection conn) {
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": Closed");
            }
            this.handler.closed(conn);
        }

        public void exception(final NHttpServerConnection conn, final Exception ex) {
            String msg = ex.getMessage();
            if (msg == null) {
                msg = "";
            }
            if (ex instanceof ConnectionClosedException ||
                    msg.contains("Connection reset by peer") ||
                    msg.contains("forcibly closed")) {
                if (this.log.isDebugEnabled()) {
                    this.log.debug(conn + ": " + msg +
                            " (Probably the keepalive connection was closed)");
                }
            } else {
                this.log.error(conn + ": " + msg, ex);
            }
            this.handler.exception(conn, ex);
        }

        public void requestReceived(
                final NHttpServerConnection conn) throws IOException, HttpException {
            HttpRequest request = conn.getHttpRequest();
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": " + request.getRequestLine());
            }
            this.handler.requestReceived(conn);
        }

        public void outputReady(
                final NHttpServerConnection conn,
                final ContentEncoder encoder) throws IOException, HttpException {
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": Output ready");
            }
            this.handler.outputReady(conn, encoder);
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": Content encoder " + encoder);
            }
        }

        public void responseReady(
                final NHttpServerConnection conn) throws IOException, HttpException {
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": Response ready");
            }
            this.handler.responseReady(conn);
        }

        public void inputReady(
                final NHttpServerConnection conn,
                final ContentDecoder decoder) throws IOException, HttpException {
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": Input ready");
            }
            this.handler.inputReady(conn, decoder);
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": Content decoder " + decoder);
            }
        }

        public void timeout(
                final NHttpServerConnection conn) throws IOException {
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": Timeout");
            }
            this.handler.timeout(conn);
        }

        public void endOfInput(
                final NHttpServerConnection conn) throws IOException {
            if (this.log.isDebugEnabled()) {
                this.log.debug(conn + ": End of input");
            }
            this.handler.endOfInput(conn);
        }

    }