helper
Class ProcessHandler

java.lang.Object
  |
  +--helper.ProcessHandler

public class ProcessHandler

extends Object

Class provides convenient way for running external program handle its standard streams, control execution and check results. Instance of this class must be created only for a single execution. If you need to execute the same command again you should create a new instance for this.

Constructor Summary

ProcessHandler(String cmdLine)
Creates instance with specified external command.

ProcessHandler(String cmdLine, File workDir)
Creates instance with specified external command which will be executed in the some work directory.

ProcessHandler(String cmdLine, PrintWriter log)
Creates instance with specified external command and log stream where debug info is printed and output of external command.

ProcessHandler(String cmdLine, PrintWriter log, File workDir, String[] envVars)
Creates instance with specified external command which will be executed in the some work directory and log stream where debug info and output of external command is printed .

ProcessHandler(String cmdLine, PrintWriter log, File workDir, String[] envVars, long timeOut)
Creates instance with specified external command which will be executed in the some work directory and

Method Summary

protected void	execute()
boolean	executeAsynchronously() Executes the command immediately returns.
boolean	executeSynchronously() Executes the command and returns only when the process exits.
protected void	flushInput()
String	getErrorText() Returns the text output by external command to stderr.
int	getExitCode() Returns exit code of the external command.
String	getOutputText() Returns the text output by external command to stdout.
boolean	isFinished() Returns the information about the final state of command execution.
boolean	isStarted() Returns information about was the command started or not.
boolean	isTimedOut()
void	kill()
void	printInputText(String str) Prints the string specified to sdtin of external command.
boolean	waitFor() This method is useful when the process was executed asynchronously.
boolean	waitFor(long timeout) This method is useful when the process was executed asynchronously.

Methods inherited from class java.lang.Object

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

Constructor Detail

ProcessHandler

public ProcessHandler(String cmdLine)

Creates instance with specified external command. Debug info and output of external command is printed to stdout.

ProcessHandler

public ProcessHandler(String cmdLine,
                      PrintWriter log)

Creates instance with specified external command and log stream where debug info is printed and output of external command.

ProcessHandler

public ProcessHandler(String cmdLine,
                      File workDir)

Creates instance with specified external command which will be executed in the some work directory. Debug info and output of external commandis printed to stdout.

ProcessHandler

public ProcessHandler(String cmdLine,
                      PrintWriter log,
                      File workDir,
                      String[] envVars)

Creates instance with specified external command which will be executed in the some work directory and log stream where debug info and output of external command is printed . The specified environment variables are set for the new process. If log stream is null, logging is printed to stdout.

ProcessHandler

public ProcessHandler(String cmdLine,
                      PrintWriter log,
                      File workDir,
                      String[] envVars,
                      long timeOut)

Creates instance with specified external command which will be executed in the some work directory and

Parameters:

log - log stream where debug info and output of external command is printed .

workDir - The working directory of the new process

envVars - The specified environment variables are set for the new process. If log stream is null, logging is printed to stdout.

timeOut - When started sychronisly, the maximum time the process will live. When the process being destroyed a log will be written out. It can be asked on isTimedOut() if it has been terminated. timeOut > 0 Waits specified time in miliSeconds for process to exit and return its status. timeOut = 0 Waits for the process to end regulary timeOut < 0 Kills the process immediately

Method Detail

isTimedOut

public boolean isTimedOut()

executeSynchronously

public boolean executeSynchronously()

Executes the command and returns only when the process exits.

Returns:

true if process was successfully started and correcly exits (exit code doesn't affect to this result).

executeAsynchronously

public boolean executeAsynchronously()

Executes the command immediately returns. The process remains in running state. Control of its state should be made by waitFor methods.

Returns:

true if process was successfully started.

kill

public void kill()

execute

protected void execute()

waitFor

public boolean waitFor()

This method is useful when the process was executed asynchronously. Waits for process to exit and return its result.

Returns:

true if process correctly exited (exit code doesn't affect to this result).

waitFor

public boolean waitFor(long timeout)

This method is useful when the process was executed asynchronously. Waits during specified time for process to exit and return its status.

Parameters:

timeOut - > 0 Waits specified time in miliSeconds for process to exit and return its status. = 0 Waits for the process to end regulary < 0 Kills the process immediately

Returns:

true if process correctly exited (exit code doesn't affect to this result).

flushInput

protected void flushInput()

getOutputText

public String getOutputText()

Returns the text output by external command to stdout.

getErrorText

public String getErrorText()

Returns the text output by external command to stderr.

printInputText

public void printInputText(String str)

Prints the string specified to sdtin of external command. '\n' is not added so if you need you should terminate the string with '\n'.

The method can also be called before the command starts its execution. Then the text is buffered and transfered to command when it will be started.

isStarted

public boolean isStarted()

Returns information about was the command started or not.

Returns:

true if the external command was found and successfully started.

isFinished

public boolean isFinished()

Returns the information about the final state of command execution.

Returns:

true if the command correctly starts, exits and was not interrupted due to timeout.

getExitCode

public int getExitCode()

Returns exit code of the external command.

Returns:

exit code of command if it was finished, -1 if not.