Package gnu.dtools.ritopt

Class SimpleProcess

java.lang.Object
java.lang.Process
gnu.dtools.ritopt.SimpleProcess
public class SimpleProcess extends Process
A SimpleProcess is used to execute a shell process, and redirect an input stream to the processes' standard input, as well as redirect the processes' standard output/error to an output stream. The processes is multithreaded to prevent deadlock.

The example below demonstrates the use of this class. 

  class ExecuteProcess {
       public static void main( String args[] ) {
           if ( args.length > 0 ) {
               String processName = args[ 0 ];
               try {
                   SimpleProcess process
                      = new SimpleProcess( Runtime.getRuntime.exec(
                                                            processName ) );
                                          );
                   int exitStatus = process.waitFor();
                   System.out.println( "The process ran successfully" 
                                       + " with an exit status of "
                                       + exitStatus + "." );
               }
               catch ( Exception e ) {
                   System.out.println( "The process was not successful. "
                                       + " Reason: " + e.getMessage() );
               }
           }
           else {
               System.err.println( "Please specify a command" );
           }
       }
  }
 
 Copyright (C) Damian Ryan Eads, 2001. All Rights Reserved.

 ritopt is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 ritopt is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with ritopt; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  • Constructor Details

    • SimpleProcess

      public SimpleProcess(Process process) throws IOException
      Constructs a SimpleProcess, redirecting System.in to the its standard input, System.out to its standard output, and System.err to its standard error.
      Throws:
      IOException

    • SimpleProcess

      public SimpleProcess(Process process, InputStream processInput, PrintStream yourOutput, PrintStream yourError) throws IOException
      Constructs a SimpleProcess, initializing it with the streams passed.
      Parameters:
      process - The target process.
      processInput - The stream that is redirected to the processes' standard input.
      yourOutput - The stream to redirect the processes's standard output.
      yourError - The stream to redirect the processes's standard input.
      Throws:
      IOException

  • Method Details

    • getOutputStream

      public OutputStream getOutputStream()
      Returns the standard input of this process.
      Specified by:
      getOutputStream in class Process
      Returns:
      The standard input of this process.

    • getInputStream

      public InputStream getInputStream()
      Returns the standard output of this process.
      Specified by:
      getInputStream in class Process
      Returns:
      The standard output of this process.

    • getErrorStream

      public InputStream getErrorStream()
      Returns the standard error of this process.
      Specified by:
      getErrorStream in class Process
      Returns:
      The standard error of this process.

    • waitFor

      public int waitFor() throws InterruptedException
      Begin redirecting the streams passed. This method should be invoked immediately after execution of a simple process to prevent thread deadlock.
      Specified by:
      waitFor in class Process
      Returns:
      The exit status of the target process.
      Throws:
      InterruptedException

    • exitValue

      public int exitValue()
      Returns the target processes' exit value.
      Specified by:
      exitValue in class Process
      Returns:
      This processes' exit value.

    • destroy

      public void destroy() throws IllegalThreadStateException
      Destroys the target process.
      Specified by:
      destroy in class Process
      Throws:
      IllegalThreadStateException