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Commons Net example source code file (FTPSClient.java)

This example Commons Net source code file (FTPSClient.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

bufferedwriter, default_prot, deprecated, ftpsclient, io, ioexception, ioexception, net, network, override, socket, ssl, sslexception, sslexception, sslsocket, sslsocket, string, string

The Commons Net FTPSClient.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.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import javax.net.ssl.KeyManager;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;

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

/**
 * FTP over SSL processing. If desired, the JVM property -Djavax.net.debug=all can be used to
 * see wire-level SSL details.
 *
 * @version $Id: FTPSClient.java 1125962 2011-05-22 13:34:53Z sebb $
 * @since 2.0
 */
public class FTPSClient extends FTPClient {

// From http://www.iana.org/assignments/port-numbers

//    ftps-data   989/tcp    ftp protocol, data, over TLS/SSL
//    ftps-data   989/udp    ftp protocol, data, over TLS/SSL
//    ftps        990/tcp    ftp protocol, control, over TLS/SSL
//    ftps        990/udp    ftp protocol, control, over TLS/SSL

    public static final int DEFAULT_FTPS_DATA_PORT = 989;
    public static final int DEFAULT_FTPS_PORT = 990;

    /** The value that I can set in PROT command  (C = Clear, P = Protected) */
    private static final String[] PROT_COMMAND_VALUE = {"C","E","S","P"};
    /** Default PROT Command */
    private static final String DEFAULT_PROT = "C";
    /** Default secure socket protocol name, i.e. TLS */
    private static final String DEFAULT_PROTOCOL = "TLS";

    /** The AUTH (Authentication/Security Mechanism) command. */
    private static final String CMD_AUTH = "AUTH";
    /**  The ADAT (Authentication/Security Data) command. */
    private static final String CMD_ADAT = "ADAT";
    /**  The PROT (Data Channel Protection Level) command. */
    private static final String CMD_PROT = "PROT";
    /**  The PBSZ (Protection Buffer Size) command. */
    private static final String CMD_PBSZ = "PBSZ";
    /**  The MIC (Integrity Protected Command) command. */
    private static final String CMD_MIC = "MIC";
    /**  The CONF (Confidentiality Protected Command) command. */
    private static final String CMD_CONF = "CONF";
    /**  The ENC (Privacy Protected Command) command. */
    private static final String CMD_ENC = "ENC";
    /**  The CCC (Clear Command Channel) command. */
    private static final String CMD_CCC = "CCC";

    /** The security mode. (True - Implicit Mode / False - Explicit Mode) */
    private final boolean isImplicit;
    /** The secure socket protocol to be used, e.g. SSL/TLS. */
    private final String protocol;
    /** The AUTH Command value */
    private String auth = DEFAULT_PROTOCOL;
    /** The context object. */
    private SSLContext context;
    /** The socket object. */
    private Socket plainSocket;
    /** Controls whether a new SSL session may be established by this socket. Default true. */
    private boolean isCreation = true;
    /** The use client mode flag. */
    private boolean isClientMode = true;
    /** The need client auth flag. */
    private boolean isNeedClientAuth = false;
    /** The want client auth flag. */
    private boolean isWantClientAuth = false;
    /** The cipher suites */
    private String[] suites = null;
    /** The protocol versions */
    private String[] protocols = null;

    /** The FTPS {@link TrustManager} implementation, default validate only: {@link TrustManagerUtils#getValidateServerCertificateTrustManager()}. */
    private TrustManager trustManager = TrustManagerUtils.getValidateServerCertificateTrustManager();

    /** The {@link KeyManager}, default null (i.e. use system default). */
    private KeyManager keyManager = null;

    /**
     * Constructor for FTPSClient.
     * Sets protocol to {@link #DEFAULT_PROTOCOL} - i.e. TLS - and security mode to explicit (isImplicit = false)
     */
    public FTPSClient() {
        this(DEFAULT_PROTOCOL, false);
    }

    /**
     * Constructor for FTPSClient, using {@link #DEFAULT_PROTOCOL} - i.e. TLS
     * @param isImplicit The security mode (Implicit/Explicit).
     */
    public FTPSClient(boolean isImplicit) {
        this(DEFAULT_PROTOCOL, isImplicit);
    }

    /**
     * Constructor for FTPSClient, using explict mode
     * @param protocol the protocol to use
     */
    public FTPSClient(String protocol) {
        this(protocol, false);
    }

    /**
     * Constructor for FTPSClient allowing specification of protocol
     * and security mode. If isImplicit is true, the port is set to
     * {@link #DEFAULT_FTPS_PORT} i.e. 990.
     *
     * @param protocol the protocol
     * @param isImplicit The security mode(Implicit/Explicit).
     */
    public FTPSClient(String protocol, boolean isImplicit) {
        super();
        this.protocol = protocol;
        this.isImplicit = isImplicit;
        if (isImplicit) {
            setDefaultPort(DEFAULT_FTPS_PORT);
        }
    }

    /**
     * Constructor for FTPSClient, using {@link #DEFAULT_PROTOCOL} - i.e. TLS
     * @param isImplicit The security mode(Implicit/Explicit).
     * @param context A pre-configured SSL Context
     */
    public FTPSClient(boolean isImplicit, SSLContext context) {
        this(DEFAULT_PROTOCOL, isImplicit);
        this.context = context;
    }

    /**
     * Constructor for FTPSClient, using {@link #DEFAULT_PROTOCOL} - i.e. TLS
     * and isImplicit {@code false}
     *
     * @param context A pre-configured SSL Context
     */
    public FTPSClient(SSLContext context) {
        this(false, context);
    }


    /**
     * Set AUTH command use value.
     * This processing is done before connected processing.
     * @param auth AUTH command use value.
     */
    public void setAuthValue(String auth) {
        this.auth = auth;
    }

    /**
     * Return AUTH command use value.
     * @return AUTH command use value.
     */
    public String getAuthValue() {
        return this.auth;
    }


    /**
     * Because there are so many connect() methods,
     * the _connectAction_() method is provided as a means of performing
     * some action immediately after establishing a connection,
     * rather than reimplementing all of the connect() methods.
     * @throws IOException If it throw by _connectAction_.
     * @see org.apache.commons.net.SocketClient#_connectAction_()
     */
    @Override
    protected void _connectAction_() throws IOException {
        // Implicit mode.
        if (isImplicit) sslNegotiation();
        super._connectAction_();
        // Explicit mode.
        if (!isImplicit) {
            execAUTH();
            sslNegotiation();
        }
    }

    /**
     * AUTH command.
     * @throws SSLException If it server reply code not equal "234" and "334".
     * @throws IOException If an I/O error occurs while either sending
     * the command.
     */
    protected void execAUTH() throws SSLException, IOException {
        int replyCode = sendCommand(CMD_AUTH, auth);
        if (FTPReply.SECURITY_MECHANISM_IS_OK == replyCode) {
            // replyCode = 334
            // I carry out an ADAT command.
        } else if (FTPReply.SECURITY_DATA_EXCHANGE_COMPLETE != replyCode) {
            throw new SSLException(getReplyString());
        }
    }

    /**
     * Performs a lazy init of the SSL context
     * @throws IOException
     */
    private void initSslContext() throws IOException {
        if(context == null) {
            context = SSLContextUtils.createSSLContext(protocol, getKeyManager(), getTrustManager());
        }
    }

    /**
     * SSL/TLS negotiation. Acquires an SSL socket of a control
     * connection and carries out handshake processing.
     * @throws IOException If server negotiation fails
     */
    protected void sslNegotiation() throws IOException {
        plainSocket = _socket_;
        initSslContext();

        SSLSocketFactory ssf = context.getSocketFactory();
        String ip = _socket_.getInetAddress().getHostAddress();
        int port = _socket_.getPort();
        SSLSocket socket =
            (SSLSocket) ssf.createSocket(_socket_, ip, port, false);
        socket.setEnableSessionCreation(isCreation);
        socket.setUseClientMode(isClientMode);
        // server mode
        if (!isClientMode) {
            socket.setNeedClientAuth(isNeedClientAuth);
            socket.setWantClientAuth(isWantClientAuth);
        }

        if (protocols != null) socket.setEnabledProtocols(protocols);
        if (suites != null) socket.setEnabledCipherSuites(suites);
        socket.startHandshake();

        _socket_ = socket;
        _controlInput_ = new BufferedReader(new InputStreamReader(
                socket .getInputStream(), getControlEncoding()));
        _controlOutput_ = new BufferedWriter(new OutputStreamWriter(
                socket.getOutputStream(), getControlEncoding()));
    }

    /**
     * Get the {@link KeyManager} instance.
     * @return The {@link KeyManager} instance
     */
    private KeyManager getKeyManager() {
        return keyManager;
    }

    /**
    * Set a {@link KeyManager} to use
    *
    * @param keyManager The KeyManager implementation to set.
    * @see org.apache.commons.net.util.KeyManagerUtils
    */
    public void setKeyManager(KeyManager keyManager) {
        this.keyManager = keyManager;
    }

    /**
     * Controls whether a new SSL session may be established by this socket.
     * @param isCreation The established socket flag.
     */
    public void setEnabledSessionCreation(boolean isCreation) {
        this.isCreation = isCreation;
    }

    /**
     * Returns true if new SSL sessions may be established by this socket.
     * When the underlying {@link Socket} instance is not SSL-enabled (i.e. an
     * instance of {@link SSLSocket} with {@link SSLSocket}{@link #getEnableSessionCreation()}) enabled,
     * this returns False.
     * @return true - Indicates that sessions may be created;
     * this is the default.
     * false - indicates that an existing session must be resumed.
     */
    public boolean getEnableSessionCreation() {
        if (_socket_ instanceof SSLSocket)
            return ((SSLSocket)_socket_).getEnableSessionCreation();
        return false;
    }

    /**
     * Configures the socket to require client authentication.
     * @param isNeedClientAuth The need client auth flag.
     */
    public void setNeedClientAuth(boolean isNeedClientAuth) {
        this.isNeedClientAuth = isNeedClientAuth;
    }

    /**
     * Returns true if the socket will require client authentication.
     * When the underlying {@link Socket} is not an {@link SSLSocket} instance, returns false.
     * @return true - If the server mode socket should request
     * that the client authenticate itself.
     */
    public boolean getNeedClientAuth() {
        if (_socket_ instanceof SSLSocket)
            return ((SSLSocket)_socket_).getNeedClientAuth();
        return false;
    }

    /**
     * Configures the socket to request client authentication,
     * but only if such a request is appropriate to the cipher
     * suite negotiated.
     * @param isWantClientAuth The want client auth flag.
     */
    public void setWantClientAuth(boolean isWantClientAuth) {
        this.isWantClientAuth = isWantClientAuth;
    }

    /**
     * Returns true if the socket will request client authentication.
     * When the underlying {@link Socket} is not an {@link SSLSocket} instance, returns false.
     * @return true - If the server mode socket should request
     * that the client authenticate itself.
     */
    public boolean getWantClientAuth() {
        if (_socket_ instanceof SSLSocket)
            return ((SSLSocket)_socket_).getWantClientAuth();
        return false;
    }

    /**
     * Configures the socket to use client (or server) mode in its first
     * handshake.
     * @param isClientMode The use client mode flag.
     */
    public void setUseClientMode(boolean isClientMode) {
        this.isClientMode = isClientMode;
    }

    /**
     * Returns true if the socket is set to use client mode
     * in its first handshake.
     * When the underlying {@link Socket} is not an {@link SSLSocket} instance, returns false.
     * @return true - If the socket should start its first handshake
     * in "client" mode.
     */
    public boolean getUseClientMode() {
        if (_socket_ instanceof SSLSocket)
            return ((SSLSocket)_socket_).getUseClientMode();
        return false;
    }

    /**
     * Controls which particular cipher suites are enabled for use on this
     * connection. Called before server negotiation.
     * @param cipherSuites The cipher suites.
     */
    public void setEnabledCipherSuites(String[] cipherSuites) {
        suites = new String[cipherSuites.length];
        System.arraycopy(cipherSuites, 0, suites, 0, cipherSuites.length);
    }

    /**
     * Returns the names of the cipher suites which could be enabled
     * for use on this connection.
     * When the underlying {@link Socket} is not an {@link SSLSocket} instance, returns null.
     * @return An array of cipher suite names, or <code>null
     */
    public String[] getEnabledCipherSuites() {
        if (_socket_ instanceof SSLSocket)
            return ((SSLSocket)_socket_).getEnabledCipherSuites();
        return null;
    }

    /**
     * Controls which particular protocol versions are enabled for use on this
     * connection. I perform setting before a server negotiation.
     * @param protocolVersions The protocol versions.
     */
    public void setEnabledProtocols(String[] protocolVersions) {
        protocols = new String[protocolVersions.length];
        System.arraycopy(protocolVersions, 0, protocols, 0, protocolVersions.length);
    }

    /**
     * Returns the names of the protocol versions which are currently
     * enabled for use on this connection.
     * When the underlying {@link Socket} is not an {@link SSLSocket} instance, returns null.
     * @return An array of protocols, or <code>null
     */
    public String[] getEnabledProtocols() {
        if (_socket_ instanceof SSLSocket)
            return ((SSLSocket)_socket_).getEnabledProtocols();
        return null;
    }

    /**
     * PBSZ command. pbsz value: 0 to (2^32)-1 decimal integer.
     * @param pbsz Protection Buffer Size.
     * @throws SSLException If the server reply code does not equal "200".
     * @throws IOException If an I/O error occurs while sending
     * the command.
     * @see #parsePBSZ(long)
     */
    public void execPBSZ(long pbsz) throws SSLException, IOException {
        if (pbsz < 0 || 4294967295L < pbsz) // 32-bit unsigned number
            throw new IllegalArgumentException();
        int status = sendCommand(CMD_PBSZ, String.valueOf(pbsz));
        if (FTPReply.COMMAND_OK != status) {
            throw new SSLException(getReplyString());
        }
    }

    /**
     * PBSZ command. pbsz value: 0 to (2^32)-1 decimal integer.
     * Issues the command and parses the response to return the negotiated value.
     * 
     * @param pbsz Protection Buffer Size.
     * @throws SSLException If the server reply code does not equal "200".
     * @throws IOException If an I/O error occurs while sending
     * the command.
     * @return the negotiated value.
     * @see #execPBSZ(long)
     * @since 3.0
     */
    public long parsePBSZ(long pbsz) throws SSLException, IOException {
        execPBSZ(pbsz);
        long minvalue = pbsz;
        String remainder = extractPrefixedData("PBSZ=", getReplyString());
        if (remainder != null) {
            long replysz = Long.parseLong(remainder);
            if (replysz < minvalue) {
                minvalue = replysz;
            }
        }
        return minvalue;
    }
    
    /**
     * PROT command.</br>
     * C - Clear</br>
     * S - Safe(SSL protocol only)</br>
     * E - Confidential(SSL protocol only)</br>
     * P - Private
     * <p>
     * <b>N.B. the method calls
     *  {@link #setSocketFactory(javax.net.SocketFactory)} and
     *  {@link #setServerSocketFactory(javax.net.ServerSocketFactory)}
     *
     * @param prot Data Channel Protection Level.
     * @throws SSLException If the server reply code does not equal "200".
     * @throws IOException If an I/O error occurs while sending
     * the command.
     */
    public void execPROT(String prot) throws SSLException, IOException {
        if (prot == null) prot = DEFAULT_PROT;
        if (!checkPROTValue(prot)) throw new IllegalArgumentException();
        if (FTPReply.COMMAND_OK != sendCommand(CMD_PROT, prot))
            throw new SSLException(getReplyString());
        if (DEFAULT_PROT.equals(prot)) {
            setSocketFactory(null);
            setServerSocketFactory(null);
        } else {
            setSocketFactory(new FTPSSocketFactory(context));
            setServerSocketFactory(new FTPSServerSocketFactory(context));
            initSslContext();
        }
    }

    /**
     * Check the value that can be set in PROT Command value.
     * @param prot Data Channel Protection Level.
     * @return True - A set point is right / False - A set point is not right
     */
    private boolean checkPROTValue(String prot) {
        for (int p = 0; p < PROT_COMMAND_VALUE.length; p++) {
            if (PROT_COMMAND_VALUE[p].equals(prot)) return true;
        }
        return false;
    }

    /**
     * Send an FTP command.
     * A successful CCC (Clear Command Channel) command causes the underlying {@link SSLSocket} 
     * instance to be assigned to a plain {@link Socket}
     * @param command The FTP command.
     * @return server reply.
     * @throws IOException If an I/O error occurs while sending the command.
     * @throws SSLException if a CCC command fails
     * @see org.apache.commons.net.ftp.FTP#sendCommand(java.lang.String)
     */
    // Would like to remove this method, but that will break any existing clients that are using CCC
    @Override
    public int sendCommand(String command, String args) throws IOException {
        int repCode = super.sendCommand(command, args);
        /* If CCC is issued, restore socket i/o streams to unsecured versions */
        if (CMD_CCC.equals(command)) {
            if (FTPReply.COMMAND_OK == repCode) {
                _socket_.close();
                _socket_ = plainSocket;
                _controlInput_ = new BufferedReader(
                    new InputStreamReader(
                        _socket_ .getInputStream(), getControlEncoding()));
                _controlOutput_ = new BufferedWriter(
                    new OutputStreamWriter(
                        _socket_.getOutputStream(), getControlEncoding()));
            } else {
                throw new SSLException(getReplyString());
            }
        }
        return repCode;
    }

    /**
     * Returns a socket of the data connection.
     * Wrapped as an {@link SSLSocket}, which carries out handshake processing.
     * @param command The textual representation of the FTP command to send.
     * @param arg The arguments to the FTP command.
     * If this parameter is set to null, then the command is sent with
     * no arguments.
     * @return corresponding to the established data connection.
     * Null is returned if an FTP protocol error is reported at any point
     * during the establishment and initialization of the connection.
     * @throws IOException If there is any problem with the connection.
     * @see FTPClient#_openDataConnection_(int, String)
     */
    @Override
    protected Socket _openDataConnection_(int command, String arg)
            throws IOException {
        Socket socket = super._openDataConnection_(command, arg);
        if (socket instanceof SSLSocket) {
            SSLSocket sslSocket = (SSLSocket)socket;

            sslSocket.setUseClientMode(isClientMode);
            sslSocket.setEnableSessionCreation(isCreation);

            // server mode
            if (!isClientMode) {
                sslSocket.setNeedClientAuth(isNeedClientAuth);
                sslSocket.setWantClientAuth(isWantClientAuth);
            }
            if (suites != null) {
                sslSocket.setEnabledCipherSuites(suites);
            }
            if (protocols != null) {
                sslSocket.setEnabledProtocols(protocols);
            }
            sslSocket.startHandshake();
        }

        return socket;
    }

    /**
     * Get the currently configured {@link TrustManager}.
     *
     * @return A TrustManager instance.
     */
    public TrustManager getTrustManager() {
        return trustManager;
    }

    /**
     * Override the default {@link TrustManager} to use.
     *
     * @param trustManager The TrustManager implementation to set.
    * @see org.apache.commons.net.util.TrustManagerUtils
     */
    public void setTrustManager(TrustManager trustManager) {
        this.trustManager = trustManager;
    }

    /**
     * Closes the connection to the FTP server and restores
     * connection parameters to the default values.
     * <p>
     * Calls {@code setSocketFactory(null)} and {@code setServerSocketFactory(null)}
     * to reset the factories that may have been changed during the session,
     * e.g. by {@link #execPROT(String)}
     * @exception IOException If an error occurs while disconnecting.
     * @since 3.0
     */
    @Override
    public void disconnect() throws IOException
    {
        super.disconnect();
        setSocketFactory(null);
        setServerSocketFactory(null);
    }

    /**
     * Send the AUTH command with the specified mechanism.
     * @param mechanism The mechanism name to send with the command.
     * @return server reply.
     * @throws IOException If an I/O error occurs while sending
     * the command.
     * @since 3.0
     */
    public int execAUTH(String mechanism) throws IOException
    {
        return sendCommand(CMD_AUTH, mechanism);
    }

    /**
     * Send the ADAT command with the specified authentication data.
     * @param data The data to send with the command.
     * @return server reply.
     * @throws IOException If an I/O error occurs while sending
     * the command.
     * @since 3.0
     */
    public int execADAT(byte[] data) throws IOException
    {
        if (data != null)
        {
            return sendCommand(CMD_ADAT, new String(Base64.encodeBase64(data)));
        }
        else
        {
            return sendCommand(CMD_ADAT);
        }
    }

    /**
     * Send the CCC command to the server.
     * The CCC (Clear Command Channel) command causes the underlying {@link SSLSocket} instance  to be assigned
     * to a plain {@link Socket} instances
     * @return server reply.
     * @throws IOException If an I/O error occurs while sending
     * the command.
     * @since 3.0
     */
    public int execCCC() throws IOException
    {
        int repCode = sendCommand(CMD_CCC);
// This will be performed by sendCommand(String, String)
//        if (FTPReply.isPositiveCompletion(repCode)) {
//            _socket_.close();
//            _socket_ = plainSocket;
//            _controlInput_ = new BufferedReader(
//                new InputStreamReader(
//                    _socket_.getInputStream(), getControlEncoding()));
//            _controlOutput_ = new BufferedWriter(
//                new OutputStreamWriter(
//                    _socket_.getOutputStream(), getControlEncoding()));
//        }
        return repCode;
    }

    /**
     * Send the MIC command with the specified data.
     * @param data The data to send with the command.
     * @return server reply.
     * @throws IOException If an I/O error occurs while sending
     * the command.
     * @since 3.0
     */
    public int execMIC(byte[] data) throws IOException
    {
        if (data != null)
        {
            return sendCommand(CMD_MIC, new String(Base64.encodeBase64(data)));
        }
        else
        {
            return sendCommand(CMD_MIC, ""); // perhaps "=" or just sendCommand(String)?
        }
    }

    /**
     * Send the CONF command with the specified data.
     * @param data The data to send with the command.
     * @return server reply.
     * @throws IOException If an I/O error occurs while sending
     * the command.
     * @since 3.0
     */
    public int execCONF(byte[] data) throws IOException
    {
        if (data != null)
        {
            return sendCommand(CMD_CONF, new String(Base64.encodeBase64(data)));
        }
        else
        {
            return sendCommand(CMD_CONF, ""); // perhaps "=" or just sendCommand(String)?
        }
    }

    /**
     * Send the ENC command with the specified data.
     * @param data The data to send with the command.
     * @return server reply.
     * @throws IOException If an I/O error occurs while sending
     * the command.
     * @since 3.0
     */
    public int execENC(byte[] data) throws IOException
    {
        if (data != null)
        {
            return sendCommand(CMD_ENC, new String(Base64.encodeBase64(data)));
        }
        else
        {
            return sendCommand(CMD_ENC, ""); // perhaps "=" or just sendCommand(String)?
        }
    }

    /**
     * Parses the given ADAT response line and base64-decodes the data.
     * @param reply The ADAT reply to parse.
     * @return the data in the reply, base64-decoded.
     * @since 3.0
     */
    public byte[] parseADATReply(String reply)
    {
        if (reply == null) return null;
        else {
            return Base64.decodeBase64(extractPrefixedData("ADAT=", reply));
        }
    }

    /**
     * Extract the data from a reply with a prefix, e.g. PBSZ=1234 => 1234
     * @param prefix the prefix to find
     * @param reply where to find the prefix
     * @return the remainder of the string after the prefix, or null if the prefix was not present.
     */
    private String extractPrefixedData(String prefix, String reply) {
        int idx = reply.indexOf(prefix);
        if (idx == -1) { 
            return null;
        }
        // N.B. Cannot use trim before substring as leading space would affect the offset.
        return reply.substring(idx+prefix.length()).trim();
    }

    // DEPRECATED - for API compatibility only - DO NOT USE

    /** @deprecated - not used - may be removed in a future release */
    @Deprecated
    public static String KEYSTORE_ALGORITHM;

    /** @deprecated - not used - may be removed in a future release */
    @Deprecated
    public static String TRUSTSTORE_ALGORITHM;

    /** @deprecated - not used - may be removed in a future release */
    @Deprecated
    public static String PROVIDER;

    /** @deprecated - not used - may be removed in a future release */
    @Deprecated
    public static String STORE_TYPE;

}
/* kate: indent-width 4; replace-tabs on; */

Other Commons Net examples (source code examples)

Here is a short list of links related to this Commons Net FTPSClient.java source code file:

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