Package org.apache.commons.exec
Class ExecuteWatchdog
java.lang.Object
org.apache.commons.exec.ExecuteWatchdog
- All Implemented Interfaces:
TimeoutObserver
Destroys a process running for too long. For example:
ExecuteWatchdog watchdog = new ExecuteWatchdog(30000); Executer exec = new Executer(myloghandler, watchdog); exec.setCommandLine(mycmdline); int exitvalue = exec.execute(); if (Execute.isFailure(exitvalue) && watchdog.killedProcess()) { // it was killed on purpose by the watchdog }When starting an asynchronous process than 'ExecuteWatchdog' is the keeper of the process handle. In some cases it is useful not to define a timeout (and pass 'INFINITE_TIMEOUT') and to kill the process explicitly using 'destroyProcess()'.
Please note that ExecuteWatchdog is processed asynchronously, e.g. it might be still attached to a process even after the DefaultExecutor.execute has returned.
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final long
The marker for an infinite timeout -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
This method will rethrow the exception that was possibly caught during the run of the process.protected void
cleanUp()
reset the monitor flag and the process.void
Destroys the running process manually.boolean
Indicates whether or not the watchdog is still monitoring the process.boolean
Indicates whether the last process run was killed.void
Watches the given process and terminates it, if it runs for too long.void
stop()
Stops the watcher.void
Called after watchdog has finished.
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Field Details
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INFINITE_TIMEOUT
The marker for an infinite timeout- See Also:
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Constructor Details
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ExecuteWatchdog
Creates a new watchdog with a given timeout.- Parameters:
timeout
- the timeout for the process in milliseconds. It must be greater than 0 or 'INFINITE_TIMEOUT'
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Method Details
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start
Watches the given process and terminates it, if it runs for too long. All information from the previous run are reset.- Parameters:
processToMonitor
- the process to monitor. It cannot benull
- Throws:
IllegalStateException
- if a process is still being monitored.
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stop
Stops the watcher. It will notify all threads possibly waiting on this object. -
destroyProcess
Destroys the running process manually. -
timeoutOccured
Called after watchdog has finished.- Specified by:
timeoutOccured
in interfaceTimeoutObserver
- Parameters:
w
- the watchdog that timed out.
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checkException
This method will rethrow the exception that was possibly caught during the run of the process. It will only remains valid once the process has been terminated either by 'error', timeout or manual intervention. Information will be discarded once a new process is ran.- Throws:
Exception
- a wrapped exception over the one that was silently swallowed and stored during the process run.
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isWatching
Indicates whether or not the watchdog is still monitoring the process.- Returns:
true
if the process is still running, otherwisefalse
.
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killedProcess
Indicates whether the last process run was killed.- Returns:
true
if the process was killedfalse
.
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cleanUp
reset the monitor flag and the process.
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