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ActiveMQ example source code file (HttpTransport.java)

This example ActiveMQ source code file (HttpTransport.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - ActiveMQ tags/keywords

callback, command, exception, exception, failed, get, get, httptransport, httpurlconnection, httpurlconnection, io, ioexception, ioexception, net, network, string, uri

The ActiveMQ HttpTransport.java source code

/**
 * 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.activemq.transport.http;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;

import org.apache.activemq.command.Command;
import org.apache.activemq.command.ConnectionInfo;
import org.apache.activemq.transport.util.TextWireFormat;
import org.apache.activemq.util.ByteArrayOutputStream;
import org.apache.activemq.util.ByteSequence;
import org.apache.activemq.util.Callback;
import org.apache.activemq.util.IOExceptionSupport;
import org.apache.activemq.util.ServiceStopper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 * @deprecated
 * @see HttpClientTransport
 */
@Deprecated
public class HttpTransport extends HttpTransportSupport {
    
    private static final Logger LOG = LoggerFactory.getLogger(HttpTransport.class);
    
    private HttpURLConnection sendConnection;
    private HttpURLConnection receiveConnection;
    private URL url;
    private String clientID;
    private volatile int receiveCounter;
    
    // private String sessionID;

    public HttpTransport(TextWireFormat wireFormat, URI remoteUrl) throws MalformedURLException {
        super(wireFormat, remoteUrl);
        url = new URL(remoteUrl.toString());
    }

    public void oneway(Object o) throws IOException {
        final Command command = (Command)o;
        try {
            if (command.getDataStructureType() == ConnectionInfo.DATA_STRUCTURE_TYPE) {
                boolean startGetThread = clientID == null;
                clientID = ((ConnectionInfo)command).getClientId();
                if (startGetThread && isStarted()) {
                    try {
                        super.doStart();
                    } catch (Exception e) {
                        throw IOExceptionSupport.create(e);
                    }
                }
            }

            HttpURLConnection connection = getSendConnection();
            String text = getTextWireFormat().marshalText(command);
            Writer writer = new OutputStreamWriter(connection.getOutputStream());
            writer.write(text);
            writer.flush();
            int answer = connection.getResponseCode();
            if (answer != HttpURLConnection.HTTP_OK) {
                throw new IOException("Failed to post command: " + command + " as response was: " + answer);
            }
            // checkSession(connection);
        } catch (IOException e) {
            throw IOExceptionSupport.create("Could not post command: " + command + " due to: " + e, e);
        }
    }

    public void run() {
        LOG.trace("HTTP GET consumer thread starting for transport: " + this);
        URI remoteUrl = getRemoteUrl();
        while (!isStopped()) {
            try {
                HttpURLConnection connection = getReceiveConnection();
                int answer = connection.getResponseCode();
                if (answer != HttpURLConnection.HTTP_OK) {
                    if (answer == HttpURLConnection.HTTP_CLIENT_TIMEOUT) {
                        LOG.trace("GET timed out");
                    } else {
                        LOG.warn("Failed to perform GET on: " + remoteUrl + " as response was: " + answer);
                    }
                } else {
                    // checkSession(connection);

                    // Create a String for the UTF content
                    receiveCounter++;
                    InputStream is = connection.getInputStream();
                    ByteArrayOutputStream baos = new ByteArrayOutputStream(connection.getContentLength() > 0 ? connection.getContentLength() : 1024);
                    int c = 0;
                    while ((c = is.read()) >= 0) {
                        baos.write(c);
                    }
                    ByteSequence sequence = baos.toByteSequence();
                    String data = new String(sequence.data, sequence.offset, sequence.length, "UTF-8");

                    Command command = (Command)getTextWireFormat().unmarshalText(data);

                    if (command == null) {
                        LOG.warn("Received null packet from url: " + remoteUrl);
                    } else {
                        doConsume(command);
                    }
                }
            } catch (Throwable e) {
                if (!isStopped()) {
                    LOG.error("Failed to perform GET on: " + remoteUrl + " due to: " + e, e);
                } else {
                    LOG.trace("Caught error after closed: " + e, e);
                }
            } finally {
                safeClose(receiveConnection);
                receiveConnection = null;
            }
        }
    }

    // Implementation methods
    // -------------------------------------------------------------------------
    protected HttpURLConnection createSendConnection() throws IOException {
        HttpURLConnection conn = (HttpURLConnection)getRemoteURL().openConnection();
        conn.setDoOutput(true);
        conn.setRequestMethod("POST");
        configureConnection(conn);
        conn.connect();
        return conn;
    }

    protected HttpURLConnection createReceiveConnection() throws IOException {
        HttpURLConnection conn = (HttpURLConnection)getRemoteURL().openConnection();
        conn.setDoOutput(false);
        conn.setDoInput(true);
        conn.setRequestMethod("GET");
        configureConnection(conn);
        conn.connect();
        return conn;
    }

    // protected void checkSession(HttpURLConnection connection)
    // {
    // String set_cookie=connection.getHeaderField("Set-Cookie");
    // if (set_cookie!=null && set_cookie.startsWith("JSESSIONID="))
    // {
    // String[] bits=set_cookie.split("[=;]");
    // sessionID=bits[1];
    // }
    // }

    protected void configureConnection(HttpURLConnection connection) {
        // if (sessionID !=null) {
        // connection.addRequestProperty("Cookie", "JSESSIONID="+sessionID);
        // }
        // else
        if (clientID != null) {
            connection.setRequestProperty("clientID", clientID);
        }
    }

    protected URL getRemoteURL() {
        return url;
    }

    protected HttpURLConnection getSendConnection() throws IOException {
        setSendConnection(createSendConnection());
        return sendConnection;
    }

    protected HttpURLConnection getReceiveConnection() throws IOException {
        setReceiveConnection(createReceiveConnection());
        return receiveConnection;
    }

    protected void setSendConnection(HttpURLConnection conn) {
        safeClose(sendConnection);
        sendConnection = conn;
    }

    protected void setReceiveConnection(HttpURLConnection conn) {
        safeClose(receiveConnection);
        receiveConnection = conn;
    }

    protected void doStart() throws Exception {
        // Don't start the background thread until the clientId has been
        // established.
        if (clientID != null) {
            super.doStart();
        }
    }

    protected void doStop(ServiceStopper stopper) throws Exception {
        stopper.run(new Callback() {
            public void execute() throws Exception {
                safeClose(sendConnection);
            }
        });
        sendConnection = null;
        stopper.run(new Callback() {
            public void execute() {
                safeClose(receiveConnection);
            }
        });
    }

    /**
     * @param connection TODO
     */
    private void safeClose(HttpURLConnection connection) {
        if (connection != null) {
            connection.disconnect();
        }
    }

    public int getReceiveCounter() {
        return receiveCounter;
    }

}

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