co.codewizards.cloudstore.core.util.childprocess

Class DumpStreamThread

java.lang.Object

java.lang.Thread

co.codewizards.cloudstore.core.util.childprocess.DumpStreamThread

All Implemented Interfaces:

Runnable

public class DumpStreamThread
extends Thread

Thread continuously reading from an InputStream and writing everything to an OutputStream.

While this functionality is useful for multiple purposes, we use DumpStreamThread primarily for child processes. When starting another process (e.g. via the ProcessBuilder), it is necessary to read the process' output. Without doing this, the child process might block forever - especially on Windows (having a very limited standard-output-buffer), this is a well-known problem.

Since the main thread (invoking the child process) usually blocks and waits for the child process to return (i.e. exit), dumping its standard-out and standard-error to a buffer or a log file is done on a separate thread.

Please note that DumpStreamThread can automatically write everything to the log. This is done via an instance of LogDumpedStreamThread.

Author:

Marco หงุ่ยตระกูล-Schulze - marco at nightlabs dot de

Nested Class Summary

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

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
DumpStreamThread(InputStream inputStream, OutputStream outputStream, org.slf4j.Logger childProcessLogger) Creates an instance of DumpStreamThread.
DumpStreamThread(InputStream inputStream, OutputStream outputStream, String childProcessLoggerName) Creates an instance of DumpStreamThread.

Method Summary

Modifier and Type	Method and Description
void	flushBuffer()
StringBuffer	getOutputStringBuffer()
int	getOutputStringBufferMaxLength()
void	interrupt()
boolean	isInterrupted()
void	run()
void	setIgnoreErrors(boolean ignoreErrors)
void	setOutputStringBuffer(StringBuffer outputStringBuffer) Sets a StringBuffer for capturing all output.
void	setOutputStringBufferMaxLength(int outputStringBufferMaxLength)
void	start()

Methods inherited from class java.lang.Thread

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

Methods inherited from class java.lang.Object

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

Constructor Detail

DumpStreamThread

public DumpStreamThread(InputStream inputStream,
                        OutputStream outputStream,
                        String childProcessLoggerName)

Creates an instance of DumpStreamThread.

Parameters:

inputStream - the stream to read from. Must not be null.

outputStream - the stream to write to. Must not be null.

childProcessLoggerName - the name of the logger. May be null if logging is not desired. In case of null, logging is completely disabled.

DumpStreamThread

public DumpStreamThread(InputStream inputStream,
                        OutputStream outputStream,
                        org.slf4j.Logger childProcessLogger)

Creates an instance of DumpStreamThread.

Parameters:

inputStream - the stream to read from. Must not be null.

outputStream - the stream to write to. Must not be null.

childProcessLogger - the logger. May be null if logging is not desired.

Method Detail

setIgnoreErrors

public void setIgnoreErrors(boolean ignoreErrors)

interrupt

public void interrupt()

Overrides:

interrupt in class Thread

isInterrupted

public boolean isInterrupted()

Overrides:

isInterrupted in class Thread

start

public void start()

Overrides:

start in class Thread

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

setOutputStringBuffer

public void setOutputStringBuffer(StringBuffer outputStringBuffer)

Sets a StringBuffer for capturing all output.

Please note, that only data read from the stream after this was set is captured. You normally want to set this StringBuffer.

This feature is only available, if logging is enabled.

Parameters:

outputStringBuffer - the StringBuffer used for capturing. May be null.

getOutputStringBuffer

public StringBuffer getOutputStringBuffer()

setOutputStringBufferMaxLength

public void setOutputStringBufferMaxLength(int outputStringBufferMaxLength)

getOutputStringBufferMaxLength

public int getOutputStringBufferMaxLength()

flushBuffer

public void flushBuffer()