com.jn.langx.commandline

类 ExecuteWatchdog

java.lang.Object

com.jn.langx.commandline.ExecuteWatchdog

所有已实现的接口:

TimeoutObserver

public class ExecuteWatchdog
extends Object
implements 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.

另请参阅:

CommandLineExecutor, Watchdog

字段概要

字段

限定符和类型	字段和说明
static long	INFINITE_TIMEOUT The marker for an infinite timeout

构造器概要

构造器

构造器和说明
ExecuteWatchdog(long timeout) Creates a new watchdog with a given timeout.

方法概要

限定符和类型	方法和说明
void	checkException() 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	destroyProcess() Destroys the running process manually.
boolean	isWatching() Indicates whether or not the watchdog is still monitoring the process.
boolean	killedProcess() Indicates whether the last process run was killed.
void	onTimeout(Watchdog w) Called after watchdog has finished.
void	start(InstructionSequence processToMonitor) Watches the given process and terminates it, if it runs for too long.
void	stop() Stops the watcher.

从类继承的方法 java.lang.Object

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

字段详细资料

INFINITE_TIMEOUT

public static final long INFINITE_TIMEOUT

The marker for an infinite timeout

另请参阅:

常量字段值

构造器详细资料

ExecuteWatchdog

public ExecuteWatchdog(long timeout)

Creates a new watchdog with a given timeout.

参数:

timeout - the timeout for the process in milliseconds. It must be greater than 0 or 'INFINITE_TIMEOUT'

方法详细资料

start

public void start(InstructionSequence processToMonitor)

Watches the given process and terminates it, if it runs for too long. All information from the previous run are reset.

参数:

processToMonitor - the process to monitor. It cannot be null

抛出:

IllegalStateException - if a process is still being monitored.

stop

public void stop()

Stops the watcher. It will notify all threads possibly waiting on this object.

destroyProcess

public void destroyProcess()

Destroys the running process manually.

onTimeout

public void onTimeout(Watchdog w)

Called after watchdog has finished.

指定者:

onTimeout 在接口中 TimeoutObserver

参数:

w - the watchdog that timed out.

checkException

public void checkException()
                    throws Exception

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.

抛出:

Exception - a wrapped exception over the one that was silently swallowed and stored during the process run.

isWatching

public boolean isWatching()

Indicates whether or not the watchdog is still monitoring the process.

返回:

true if the process is still running, otherwise false.

killedProcess

public boolean killedProcess()

Indicates whether the last process run was killed.

返回:

true if the process was killed false.

cleanUp

protected void cleanUp()

reset the monitor flag and the process.