baseexec.java

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/*
*  Copyright (c) 2001 Sun Microsystems, Inc.  All rights
*  reserved.
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*  1. Redistributions of source code must retain the above copyright
*  notice, this list of conditions and the following disclaimer.
*
*  2. Redistributions in binary form must reproduce the above copyright
*  notice, this list of conditions and the following disclaimer in
*  the documentation and/or other materials provided with the
*  distribution.
*
*  3. The end-user documentation included with the redistribution,
*  if any, must include the following acknowledgment:
*  "This product includes software developed by the
*  Sun Microsystems, Inc. for Project JXTA."
*  Alternately, this acknowledgment may appear in the software itself,
*  if and wherever such third-party acknowledgments normally appear.
*
*  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
*  must not be used to endorse or promote products derived from this
*  software without prior written permission. For written
*  permission, please contact Project JXTA at http://www.jxta.org.
*
*  5. Products derived from this software may not be called "JXTA",
*  nor may "JXTA" appear in their name, without prior written
*  permission of Sun.
*
*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
*  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
*  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
*  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
*  SUCH DAMAGE.
*  ====================================================================
*
*  This software consists of voluntary contributions made by many
*  individuals on behalf of Project JXTA.  For more
*  information on Project JXTA, please see
*  <http://www.jxta.org/>.
*
*  This license is based on the BSD license adopted by the Apache Foundation.
*
*  $Id: BaseExec.java,v 1.1 2004/12/19 23:55:38 gonzo Exp $
*/
package net.jxta.myjxta.util.exec;

import java.net.URL;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;

/**
 * Base class for all execs on all platforms.
 *
 * @version $Id: BaseExec.java,v 1.1 2004/12/19 23:55:38 gonzo Exp $
 *
 * @author james todd [gonzo at jxta dot org]
 * @author mike mcangus [mcangus at jxta dot org]
 */

class BaseExec
    implements Exec {

    /**
     * Returns the OS-specific process that will execute the specified command.
     * 
     * @param command The command string to be executed.
     * @return the OS-specific process that will execute the specified command.
     */
    public Process exec(String command) {
        Process p = null;

        try {
            p = Runtime.getRuntime().exec(command);
        } catch (IOException ignored) {
            // ignored exception
        }

        return p;
    }

    /**
     * Returns the OS-specific result code for the specified command.
     * 
     * @param command The command string to be executed.
     * @return the OS-specific result code for the specified command.
     */
    public int execValue(String command) {
        Process p = exec(command);

        if (p != null) {
            try {
                p.waitFor();
            } catch (InterruptedException ignored) {
                // ignored exception
            }
        }

        return p != null ? p.exitValue() : -1;
    }

    /**
     * Returns a BufferedReader which gives access to the output of the specified command.
     * 
     * @param command The command string to be executed.
     * @return a BufferedReader which gives access to the output of the specified command.
     */
    public BufferedReader execReader(String command) {
        Process p = exec(command);

        if (p != null) {
            p.exitValue();
        }

        return (p != null ?
                new BufferedReader(new InputStreamReader(p.getInputStream())) :
                null);
    }

    /**
     * Returns the OS-specific oricess required to access the specified URL.
     * 
     * @param doc The URL to be accessed..
     * @return the OS-specific process required to access the specified URL.
     */
    public Process execDocument(URL doc) {
        return exec(doc.toString());
    }
}