Package uk.ac.starlink.topcat

Class Executor

  • public abstract class Executor
extends java.lang.Object
    Defines an object which can execute a system Process. This is basically a convenience wrapper for Process which takes care of the stream output and so on. It's not completely general purpose, it's designed for running little shell commands - if you try to run something which spews out a huge amount of output you could have trouble.
    Since:
    9 Jun 2005
    Author:
    Mark Taylor (Starlink)

    • Constructor Summary

      Constructors 
      Constructor Description
      Executor()  

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      static Executor createExecutor​(java.lang.String line)
      Returns an executor which executes a single command line.
      static Executor createExecutor​(java.lang.String[] argv)
      Returns an executor which executes a command made of words.
      int executeSynchronously​(boolean isCapture)
      Calls getProcess() and attempts to execute it synchronously.
      java.lang.String getErr()
      Returns the standard error which resulted from running the process, if execution was done in capturing mode.
      abstract java.lang.String getLine()
      Returns a representation of the command line executed.
      java.lang.String getOut()
      Returns the standard output which resulted from running the process, if execution was done in capturing mode.
      abstract java.lang.Process getProcess()
      Returns a system process to be executed.
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • Executor

        public Executor()

    • Method Detail

      • getProcess

        public abstract java.lang.Process getProcess()
                                      throws java.io.IOException
        Returns a system process to be executed.
        Returns:
        new process
        Throws:
        java.io.IOException

      • getLine

        public abstract java.lang.String getLine()
        Returns a representation of the command line executed.
        Returns:
        command line

      • getOut

        public java.lang.String getOut()
        Returns the standard output which resulted from running the process, if execution was done in capturing mode.
        Returns:
        stdout content

      • getErr

        public java.lang.String getErr()
        Returns the standard error which resulted from running the process, if execution was done in capturing mode.
        Returns:
        stderr content

      • executeSynchronously

        public int executeSynchronously​(boolean isCapture)
                         throws java.io.IOException,
                                java.lang.InterruptedException
        Calls getProcess() and attempts to execute it synchronously. Can be run only once on this object.

        If isCapture is set true, the getOut() and getErr() methods can be used after this call to get the results from stdout and stderr. Otherwise, the process output streams go to the JVM's stdout/stderr.

        Parameters:
        isCapture - true to capture output and return it as the outcome message, false to let it go to stdout
        Returns:
        exit status (0 is OK)
        Throws:
        java.io.IOException
        java.lang.InterruptedException

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • createExecutor

        public static Executor createExecutor​(java.lang.String line)
        Returns an executor which executes a single command line.
        Parameters:
        line - shell command line
        Returns:
        executor

      • createExecutor

        public static Executor createExecutor​(java.lang.String[] argv)
        Returns an executor which executes a command made of words.
        Parameters:
        argv - argument vector
        Returns:
        executor