PrintCommandListener.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
*
* https://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;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.Locale;
import java.util.Objects;
import org.apache.commons.net.io.Util;
/**
* This is a support class for some example programs. It is a sample implementation of the ProtocolCommandListener interface which just prints out to a
* specified stream all command/reply traffic.
*
* @since 2.0
*/
public class PrintCommandListener implements ProtocolCommandListener {
private static final String DIRECTION_MARKER_RECEIVE = "< ";
private static final String DIRECTION_MARKER_SEND = "> ";
private static final String HIDDEN_MARKER = " *******";
private static final String CMD_LOGIN = "LOGIN";
private static final String CMD_USER = "USER";
private static final String CMD_PASS = "PASS";
private final PrintWriter writer;
private final boolean noLogin;
private final char eolMarker;
private final boolean showDirection;
/**
* Constructs an instance which prints everything using the default Charset.
*
* @param printStream where to write the commands and responses e.g. System.out
* @since 3.0
*/
@SuppressWarnings("resource")
public PrintCommandListener(final PrintStream printStream) {
this(Util.newPrintWriter(printStream));
}
/**
* Constructs an instance which optionally suppresses login command text and indicates where the EOL starts with the specified character.
*
* @param printStream where to write the commands and responses
* @param suppressLogin if {@code true}, only print command name for login
* @since 3.0
*/
@SuppressWarnings("resource")
public PrintCommandListener(final PrintStream printStream, final boolean suppressLogin) {
this(Util.newPrintWriter(printStream), suppressLogin);
}
/**
* Constructs an instance which optionally suppresses login command text and indicates where the EOL starts with the specified character.
*
* @param printStream where to write the commands and responses
* @param suppressLogin if {@code true}, only print command name for login
* @param eolMarker if non-zero, add a marker just before the EOL.
* @since 3.0
*/
@SuppressWarnings("resource")
public PrintCommandListener(final PrintStream printStream, final boolean suppressLogin, final char eolMarker) {
this(Util.newPrintWriter(printStream), suppressLogin, eolMarker);
}
/**
* Constructs an instance which optionally suppresses login command text and indicates where the EOL starts with the specified character.
*
* @param printStream where to write the commands and responses
* @param suppressLogin if {@code true}, only print command name for login
* @param eolMarker if non-zero, add a marker just before the EOL.
* @param showDirection if {@code true}, add {@code "> "} or {@code "< "} as appropriate to the output
* @since 3.0
*/
@SuppressWarnings("resource")
public PrintCommandListener(final PrintStream printStream, final boolean suppressLogin, final char eolMarker, final boolean showDirection) {
this(Util.newPrintWriter(printStream), suppressLogin, eolMarker, showDirection);
}
/**
* Constructs the default instance which prints everything.
*
* @param writer where to write the commands and responses
*/
public PrintCommandListener(final PrintWriter writer) {
this(writer, false);
}
/**
* Constructs an instance which optionally suppresses login command text.
*
* @param writer where to write the commands and responses
* @param suppressLogin if {@code true}, only print command name for login
* @since 3.0
*/
public PrintCommandListener(final PrintWriter writer, final boolean suppressLogin) {
this(writer, suppressLogin, (char) 0);
}
/**
* Constructs an instance which optionally suppresses login command text and indicates where the EOL starts with the specified character.
*
* @param writer where to write the commands and responses
* @param suppressLogin if {@code true}, only print command name for login
* @param eolMarker if non-zero, add a marker just before the EOL.
* @since 3.0
*/
public PrintCommandListener(final PrintWriter writer, final boolean suppressLogin, final char eolMarker) {
this(writer, suppressLogin, eolMarker, false);
}
/**
* Constructs an instance which optionally suppresses login command text and indicates where the EOL starts with the specified character.
*
* @param writer where to write the commands and responses, not null.
* @param suppressLogin if {@code true}, only print command name for login
* @param eolMarker if non-zero, add a marker just before the EOL.
* @param showDirection if {@code true}, add {@code ">} " or {@code "< "} as appropriate to the output
* @since 3.0
*/
public PrintCommandListener(final PrintWriter writer, final boolean suppressLogin, final char eolMarker, final boolean showDirection) {
this.writer = Objects.requireNonNull(writer, "writer");
this.noLogin = suppressLogin;
this.eolMarker = eolMarker;
this.showDirection = showDirection;
}
private String getCommand(final ProtocolCommandEvent event) {
return Objects.toString(event.getCommand()).toUpperCase(Locale.ROOT);
}
private String getMessage(final ProtocolCommandEvent event) {
return Objects.toString(event.getMessage());
}
private String getPrintableString(final String msg) {
if (eolMarker == 0) {
return msg;
}
final int pos = msg.indexOf(SocketClient.NETASCII_EOL);
if (pos > 0) {
final StringBuilder sb = new StringBuilder(msg + 1);
sb.append(msg.substring(0, pos));
sb.append(eolMarker);
sb.append(msg.substring(pos));
return sb.toString();
}
return msg;
}
@Override
public void protocolCommandSent(final ProtocolCommandEvent event) {
if (showDirection) {
writer.print(DIRECTION_MARKER_SEND);
}
if (noLogin) {
final String cmd = getCommand(event);
if (CMD_PASS.equals(cmd) || CMD_USER.equals(cmd)) {
writer.print(cmd);
writer.println(HIDDEN_MARKER); // Don't bother with EOL marker for this!
} else if (CMD_LOGIN.equals(cmd)) { // IMAP
String msg = getMessage(event);
msg = msg.substring(0, msg.indexOf(CMD_LOGIN) + CMD_LOGIN.length());
writer.print(msg);
writer.println(HIDDEN_MARKER); // Don't bother with EOL marker for this!
} else {
writer.print(getPrintableString(getMessage(event)));
}
} else {
writer.print(getPrintableString(getMessage(event)));
}
writer.flush();
}
@Override
public void protocolReplyReceived(final ProtocolCommandEvent event) {
if (showDirection) {
writer.print(DIRECTION_MARKER_RECEIVE);
}
final String message = getMessage(event);
final char last = message.charAt(message.length() - 1);
writer.print(message);
if (last != '\r' && last != '\n') {
writer.println();
}
writer.flush();
}
}