Commons Net example source code file (FTPHTTPClient.java)

This example Commons Net source code file (FTPHTTPClient.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 - Commons Net tags/keywords

base64, bufferedreader, ftphttpclient, ftphttpclient, io, ioexception, ioexception, net, network, outputstream, override, socket, socket, string, string, stringbuilder, unsupportedencodingexception, util

The Commons Net FTPHTTPClient.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.commons.net.ftp;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.Socket;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.net.util.Base64;

/**
 * Experimental attempt at FTP client that tunnels over an HTTP proxy connection.
 *
 * @author rory
 * @since 2.2
 */
public class FTPHTTPClient extends FTPClient {
    private final String proxyHost;
    private final int proxyPort;
    private final String proxyUsername;
    private final String proxyPassword;
    private String host;
    private int port;

    private final byte[] CRLF;
    private final Base64 base64 = new Base64();

    public FTPHTTPClient(String proxyHost, int proxyPort, String proxyUser, String proxyPass) {
        this.proxyHost = proxyHost;
        this.proxyPort = proxyPort;
        this.proxyUsername = proxyUser;
        this.proxyPassword = proxyPass;

        try {
            CRLF = "\r\n".getBytes(getControlEncoding());
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }

    public FTPHTTPClient(String proxyHost, int proxyPort) {
        this(proxyHost, proxyPort, null, null);
    }


    @Override
    protected Socket _openDataConnection_(int command, String arg)
    throws IOException {
        Socket socket = new Socket(host, port);
        InputStream is = socket.getInputStream();
        OutputStream os = socket.getOutputStream();

        tunnelHandshake(host, port, is, os);

        return socket;
    }

    @Override
    public void connect(String host, int port) throws SocketException,
    IOException {
        this.host = host;
        this.port = port;

        _socket_ = new Socket(proxyHost, proxyPort);
        _input_ = _socket_.getInputStream();
        _output_ = _socket_.getOutputStream();
        try {
            tunnelHandshake(host, port, _input_, _output_);
        }
        catch (Exception e) {
            IOException ioe = new IOException("Could not connect to " + host);
            ioe.initCause(e);
            throw ioe;
        }
    }

    private void tunnelHandshake(String host, int port, InputStream input, OutputStream output) throws IOException,
    UnsupportedEncodingException {
        final String connectString = "CONNECT "  + host + ":" + port  + " HTTP/1.1";

        _output_.write(connectString.getBytes(getControlEncoding()));
        _output_.write(CRLF);

        if (proxyUsername != null && proxyPassword != null) {
            final String header = "Proxy-Authorization: Basic "
                + base64.encode(proxyUsername + ":" + proxyPassword) + "\r\n";
            _output_.write(header.getBytes("UTF-8"));
            _output_.write(CRLF);

            List<String> response = new ArrayList();
            BufferedReader reader = new BufferedReader(
                    new InputStreamReader(_input_));

            for (String line = reader.readLine(); line != null
            && line.length() > 0; line = reader.readLine()) {
                response.add(line);
            }

            int size = response.size();
            if (size == 0) {
                throw new IOException("No response from proxy");
            }

            String code = null;
            String resp = response.get(0);
            if (resp.startsWith("HTTP/") && resp.length() >= 12) {
                code = resp.substring(9, 12);
            } else {
                throw new IOException("Invalid response from proxy: " + resp);
            }

            if (!"200".equals(code)) {
                StringBuilder msg = new StringBuilder();
                msg.append("HTTPTunnelConnector: connection failed\r\n");
                msg.append("Response received from the proxy:\r\n");
                for (String line : response) {
                    msg.append(line);
                    msg.append("\r\n");
                }
                throw new IOException(msg.toString());
            }
        }
    }
}