public static SocksProxySocket connectViaSocks4Proxy(String remoteHost,
    int remotePort,
    String proxyHost,
    int proxyPort,
    String userId) throws UnknownHostException, IOException 
{
        SocksProxySocket proxySocket = new SocksProxySocket(remoteHost,
                remotePort, proxyHost, proxyPort);
        try {
            InputStream proxyIn = proxySocket.getInputStream();
            OutputStream proxyOut = proxySocket.getOutputStream();
            InetAddress hostAddr = InetAddress.getByName(remoteHost);
            proxyOut.write(SOCKS4);
            proxyOut.write(CONNECT);
            proxyOut.write((remotePort  > > > 8) & 0xff);
            proxyOut.write(remotePort & 0xff);
            proxyOut.write(hostAddr.getAddress());
            proxyOut.write(userId.getBytes());
            proxyOut.write(NULL_TERMINATION);
            proxyOut.flush();
            int res = proxyIn.read();
            if (res == -1) {
                throw new IOException("SOCKS4 server " + proxyHost + ":" +
                    proxyPort + " disconnected");
            }
            if (res != 0x00) {
                throw new IOException("Invalid response from SOCKS4 server (" +
                    res + ") " + proxyHost + ":" + proxyPort);
            }
            int code = proxyIn.read();
            if (code != 90) {
                if ((code  > 90) && (code <  93)) {
                    throw new IOException(
                        "SOCKS4 server unable to connect, reason: " +
                        SOCKSV4_ERROR[code - 91]);
                } else {
                    throw new IOException(
                        "SOCKS4 server unable to connect, reason: " + code);
                }
            }
            byte[] data = new byte[6];
            if (proxyIn.read(data, 0, 6) != 6) {
                throw new IOException(
                    "SOCKS4 error reading destination address/port");
            }
            proxySocket.providerDetail = data[2] + "." + data[3] + "." +
                data[4] + "." + data[5] + ":" + ((data[0] < <  8) | data[1]);
        } catch (SocketException e) {
            throw new SocketException("Error communicating with SOCKS4 server " +
                proxyHost + ":" + proxyPort + ", " + e.getMessage());
        }
        return proxySocket;
}

 public static SocksProxySocket connectViaSocks5Proxy(String remoteHost,
    int remotePort,
    String proxyHost,
    int proxyPort,
    String username,
    String password) throws UnknownHostException, IOException 
{
        return connectViaSocks5Proxy(remoteHost, remotePort, proxyHost,
            proxyPort, false, username, password);
}

 public static SocksProxySocket connectViaSocks5Proxy(String remoteHost,
    int remotePort,
    String proxyHost,
    int proxyPort,
    boolean localLookup,
    String username,
    String password) throws UnknownHostException, IOException 
{
        SocksProxySocket proxySocket = new SocksProxySocket(remoteHost,
                remotePort, proxyHost, proxyPort);
        try {
            InputStream proxyIn = proxySocket.getInputStream();
            OutputStream proxyOut = proxySocket.getOutputStream();
            byte[] request = {
                (byte) SOCKS5, (byte) 0x02, (byte) 0x00, (byte) 0x02
            };
            byte[] reply = new byte[2];
            proxyOut.write(request);
            proxyOut.flush();
            int res = proxyIn.read();
            if (res == -1) {
                throw new IOException("SOCKS5 server " + proxyHost + ":" +
                    proxyPort + " disconnected");
            }
            if (res != 0x05) {
                throw new IOException("Invalid response from SOCKS5 server (" +
                    res + ") " + proxyHost + ":" + proxyPort);
            }
            int method = proxyIn.read();
            switch (method) {
            case 0x00:
                break;
            case 0x02:
                performAuthentication(proxyIn, proxyOut, username, password,
                    proxyHost, proxyPort);
                break;
            default:
                throw new IOException(
                    "SOCKS5 server does not support our authentication methods");
            }
            if (localLookup) {
                InetAddress hostAddr;
                try {
                    hostAddr = InetAddress.getByName(remoteHost);
                } catch (UnknownHostException e) {
                    throw new IOException("Can't do local lookup on: " +
                        remoteHost + ", try socks5 without local lookup");
                }
                request = new byte[] {
                        (byte) SOCKS5, (byte) 0x01, (byte) 0x00, (byte) 0x01
                    };
                proxyOut.write(request);
                proxyOut.write(hostAddr.getAddress());
            } else {
                request = new byte[] {
                        (byte) SOCKS5, (byte) 0x01, (byte) 0x00, (byte) 0x03
                    };
                proxyOut.write(request);
                proxyOut.write(remoteHost.length());
                proxyOut.write(remoteHost.getBytes());
            }
            proxyOut.write((remotePort  > > > 8) & 0xff);
            proxyOut.write(remotePort & 0xff);
            proxyOut.flush();
            res = proxyIn.read();
            if (res != 0x05) {
                throw new IOException("Invalid response from SOCKS5 server (" +
                    res + ") " + proxyHost + ":" + proxyPort);
            }
            int status = proxyIn.read();
            if (status != 0x00) {
                if ((status  > 0) && (status <  9)) {
                    throw new IOException(
                        "SOCKS5 server unable to connect, reason: " +
                        SOCKSV5_ERROR[status]);
                } else {
                    throw new IOException(
                        "SOCKS5 server unable to connect, reason: " + status);
                }
            }
            proxyIn.read();
            int aType = proxyIn.read();
            byte[] data = new byte[255];
            switch (aType) {
            case 0x01:
                if (proxyIn.read(data, 0, 4) != 4) {
                    throw new IOException("SOCKS5 error reading address");
                }
                proxySocket.providerDetail = data[0] + "." + data[1] + "." +
                    data[2] + "." + data[3];
                break;
            case 0x03:
                int n = proxyIn.read();
                if (proxyIn.read(data, 0, n) != n) {
                    throw new IOException("SOCKS5 error reading address");
                }
                proxySocket.providerDetail = new String(data);
                break;
            default:
                throw new IOException("SOCKS5 gave unsupported address type: " +
                    aType);
            }
            if (proxyIn.read(data, 0, 2) != 2) {
                throw new IOException("SOCKS5 error reading port");
            }
            proxySocket.providerDetail += (":" + ((data[0] < <  8) | data[1]));
        } catch (SocketException e) {
            throw new SocketException("Error communicating with SOCKS5 server " +
                proxyHost + ":" + proxyPort + ", " + e.getMessage());
        }
        return proxySocket;
}

 public String getProviderDetail() 
{
        return providerDetail;
}

 public String toString() 
{
        return "SocksProxySocket[addr=" + getInetAddress() + ",port=" +
        getPort() + ",localport=" + getLocalPort() + "]";
}