rexectask.java

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/*
 *  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.tools.ant.taskdefs.optional.net;

import org.apache.commons.net.bsd.RExecClient;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Calendar;
import java.util.Enumeration;
import java.util.Vector;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;

/**
 * Automates the rexec protocol.
 *
 * @since Ant 1.6
 */

public class RExecTask extends Task {

    private static final int PAUSE_TIME = 250;

    /**
     *  The userid to login with, if automated login is used
     */
    private String userid  = null;

    /**
     *  The password to login with, if automated login is used
     */
    private String password = null;

    /**
     *  The command to execute
     */
    private String command = null;

    /**
     *  The server to connect to.
     */
    private String server  = null;

    /**
     *  The tcp port to connect to.
     */
    private int port = RExecClient.DEFAULT_PORT;

    /**
     *  The list of read/write commands for this session
     */
    private Vector rexecTasks = new Vector();

    /**
     *  If true, adds a CR to beginning of login script
     */
    private boolean addCarriageReturn = false;

    /**
     *  Default time allowed for waiting for a valid response
     *  for all child reads.  A value of 0 means no limit.
     */
    private Integer defaultTimeout = null;

    /**
     *  This class is the parent of the Read and Write tasks.
     *  It handles the common attributes for both.
     */
    public class RExecSubTask {
        // CheckStyle:VisibilityModifier OFF - bc
        protected String taskString = "";
        // CheckStyle:VisibilityModifier ON

        /**
         * Execute the subtask.
         * @param rexec the client
         * @throws BuildException always as it is not allowed to instantiate this object
         */
        public void execute(AntRExecClient rexec)
                throws BuildException {
            throw new BuildException("Shouldn't be able instantiate a SubTask directly");
        }

        /**
         *  the message as nested text
         * @param s the nested text
         */
        public void addText(String s) {
            setString(getProject().replaceProperties(s));
        }

        /**
         * the message as an attribute
         * @param s a <code>String</code> value
         */
        public void setString(String s) {
           taskString += s;
        }
    }

    /**
     *  Sends text to the connected server
     */
    public class RExecWrite extends RExecSubTask {
        private boolean echoString = true;
        /**
         * Execute the write exec task.
         * @param rexec the task to use
         * @throws BuildException on error
         */
        public void execute(AntRExecClient rexec)
               throws BuildException {
           rexec.sendString(taskString, echoString);
        }

        /**
         * Whether or not the message should be echoed to the log.
         * Defaults to <code>true</code>.
         * @param b a <code>boolean</code> value
         */
        public void setEcho(boolean b) {
           echoString = b;
        }
    }

    /**
     *  Reads the output from the connected server
     *  until the required string is found or we time out.
     */
    public class RExecRead extends RExecSubTask {
        private Integer timeout = null;
        /**
         * Execute the read exec task.
         * @param rexec the task to use
         * @throws BuildException on error
         */
        public void execute(AntRExecClient rexec)
               throws BuildException {
            rexec.waitForString(taskString, timeout);
        }
        /**
         *  a timeout value that overrides any task wide timeout.
         * @param i an <code>Integer</code> value
         */
        public void setTimeout(Integer i) {
           this.timeout = i;
        }

        /**
         * Sets the default timeout if none has been set already
         * @param defaultTimeout an <code>Integer</code> value
         * @ant.attribute ignore="true"
         */
        public void setDefaultTimeout(Integer defaultTimeout) {
           if (timeout == null) {
              timeout = defaultTimeout;
           }
        }
    }

    /**
     *  This class handles the abstraction of the rexec protocol.
     *  Currently it is a wrapper around <a
     *  href="http://jakarta.apache.org/commons/net/index.html">Jakarta
     *  Commons Net</a>.
     */
    public class AntRExecClient extends RExecClient {
        /**
         * Read from the rexec session until the string we are
         * waiting for is found
         * @param s The string to wait on
         */
        public void waitForString(String s) {
            waitForString(s, null);
        }

        /**
         * Read from the rexec session until the string we are
         * waiting for is found or the timeout has been reached
         * @param s The string to wait on
         * @param timeout The maximum number of seconds to wait
         */
        public void waitForString(String s, Integer timeout) {
            InputStream is = this.getInputStream();
            try {
                StringBuffer sb = new StringBuffer();
                if (timeout == null || timeout.intValue() == 0) {
                    while (sb.toString().indexOf(s) == -1) {
                        sb.append((char) is.read());
                    }
                } else {
                    Calendar endTime = Calendar.getInstance();
                    endTime.add(Calendar.SECOND, timeout.intValue());
                    while (sb.toString().indexOf(s) == -1) {
                        while (Calendar.getInstance().before(endTime)
                            && is.available() == 0) {
                            Thread.sleep(PAUSE_TIME);
                        }
                        if (is.available() == 0) {
                            throw new BuildException(
                                "Response timed-out waiting for \"" + s + '\"',
                                getLocation());
                        }
                        sb.append((char) is.read());
                    }
                }
                log(sb.toString(), Project.MSG_INFO);
            } catch (BuildException be) {
                throw be;
            } catch (Exception e) {
                throw new BuildException(e, getLocation());
            }
        }

        /**
         * Write this string to the rexec session.
         * @param s          the string to write
         * @param echoString if true log the string sent
         */