nl.knowledgeplaza.util
Class Exec

java.lang.Object
  java.lang.Thread
      nl.knowledgeplaza.util.Exec

All Implemented Interfaces:

java.lang.Runnable

public class Exec
extends java.lang.Thread

Implements an exec() interface. The primary reason for this class is to insulate the developer from the vagaries of Runtime.exec(), which appears to have a number of problems depending on the environment in which it is run.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Exec(java.lang.String[] argv, java.lang.String[] envp)
Create an exec object that will throw away all output.

Exec(java.lang.String[] argv, java.lang.String[] envp, java.io.PrintWriter pWriter)
Create an exec object that will write output to a PrintWriter.

Exec(java.lang.String[] argv, java.lang.String[] envp, java.lang.StringBuffer sBuffer)
Create an exec object that will write output into StringBuffer.

Method Summary

void	debugExec(java.lang.StringBuffer buf) Use this to append the parameters into the results.
void	dump() Use this to dump the parameters to System.err.
void	exec() Run the program.
int	getExitValue() Get the exit value of the exec().
void	run() Runtime.exec() has a problem in that is the output streams (stdout and stderr) are not read in a timely manner (Bug parade indicates 512 byte buffers), the process will HANG as the stream BLOCKS forever on readLn().
void	setErrPrefix(java.lang.String errPfx) Set the string that will prefix all stderr lines.
void	setOutPrefix(java.lang.String outPfx) Set the string that will prefix all stdout lines.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

Exec

public Exec(java.lang.String[] argv,
            java.lang.String[] envp)

Create an exec object that will throw away all output.

Exec

public Exec(java.lang.String[] argv,
            java.lang.String[] envp,
            java.lang.StringBuffer sBuffer)

Create an exec object that will write output into StringBuffer.

Exec

public Exec(java.lang.String[] argv,
            java.lang.String[] envp,
            java.io.PrintWriter pWriter)

Create an exec object that will write output to a PrintWriter.

Method Detail

setErrPrefix

public void setErrPrefix(java.lang.String errPfx)

Set the string that will prefix all stderr lines.

setOutPrefix

public void setOutPrefix(java.lang.String outPfx)

Set the string that will prefix all stdout lines.

getExitValue

public int getExitValue()

Get the exit value of the exec(). The value is not valid until exec() completes.

exec

public void exec()

Run the program.

run

public void run()

Runtime.exec() has a problem in that is the output streams (stdout and stderr) are not read in a timely manner (Bug parade indicates 512 byte buffers), the process will HANG as the stream BLOCKS forever on readLn(). To fix this, we must start a thread for each stream to help ensure the data is read in a timely fashion.

Specified by:

run in interface java.lang.Runnable

Overrides:

run in class java.lang.Thread

dump

public void dump()

Use this to dump the parameters to System.err.

debugExec

public void debugExec(java.lang.StringBuffer buf)

Use this to append the parameters into the results.