Package com.norconex.commons.lang.io

Class InputStreamConsumer

java.lang.Object

java.lang.Thread

com.norconex.commons.lang.io.InputStreamConsumer

All Implemented Interfaces:

Runnable

public class InputStreamConsumer
extends Thread

A stream consumer will read all it can from a stream in its own thread. This is often required by some processes/operating systems in order to prevent application freeze. For example, this is a way to capture the STDOUT and STDERR from a process. This class also allows to "listen" to what is being read. Listeners should not be considered thread-safe. If you share a listener between threads, make sure to have unique types to identify each one or the content being streamed from different threads can easily be mixed up in the order sent and is likely not a desired behavior.

Since:

1.13.0

Author:

Pascal Essiembre

Nested Class Summary

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

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_CHUNK_SIZE

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor	Description
InputStreamConsumer(InputStream input)	Constructor.
InputStreamConsumer(InputStream input, int chunkSize, String type, IInputStreamListener... listeners)	Constructor.
InputStreamConsumer(InputStream input, String type, IInputStreamListener... listeners)	Constructor.

Method Summary

Modifier and Type	Method	Description
protected void	afterStreaming()	Invoked just after steaming ended, before the thread dies.
protected void	beforeStreaming()	Invoked just before steaming begins, in a new thread.
static void	consume(InputStream input)	Convenience method for creasing a consumer instance and starting it.
static void	consume(InputStream input, int chunkSize, String type, IInputStreamListener... listeners)	Convenience method for creasing a consumer instance, starting it, and waiting for it to complete.
static void	consume(InputStream input, String type, IInputStreamListener... listeners)	Convenience method for creasing a consumer instance and starting it.
static void	consumeAndWait(InputStream input)	Convenience method for creasing a consumer instance, starting it, and waiting for it to complete.
static void	consumeAndWait(InputStream input, int chunkSize, String type, IInputStreamListener... listeners)	Convenience method for creasing a consumer instance, starting it, and waiting for it to complete.
static void	consumeAndWait(InputStream input, String type, IInputStreamListener... listeners)	Convenience method for creasing a consumer instance and starting it.
IInputStreamListener[]	getStreamListeners()	Returns stream listeners.
String	getType()	Gets the stream type or null if no type was set.
void	run()
void	startAndWait()	Starts this consumer thread and wait for it to complete before returning.

Methods inherited from class java.lang.Thread

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

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CHUNK_SIZE

public static final int DEFAULT_CHUNK_SIZE

See Also:

Constant Field Values

Constructor Detail

InputStreamConsumer

public InputStreamConsumer(InputStream input)

Constructor.

Parameters:

input - input stream

InputStreamConsumer

public InputStreamConsumer(InputStream input,
                           String type,
                           IInputStreamListener... listeners)

Constructor.

Parameters:

input - input stream

type - an optional way to identify each portion being read to stream listeners. Useful when listeners are shared. Can be null.

listeners - input stream listeners

InputStreamConsumer

public InputStreamConsumer(InputStream input,
                           int chunkSize,
                           String type,
                           IInputStreamListener... listeners)

Constructor.

Parameters:

input - input stream

chunkSize - how many bytes to read at once before (will also be the maximum byte array size sent to listeners)

type - an optional way to identify each portion being read to stream listeners. Useful when listeners are shared. Can be null.

listeners - input stream listeners

Method Detail

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

getStreamListeners

public IInputStreamListener[] getStreamListeners()

Returns stream listeners.

Returns:

the listeners

getType

public String getType()

Gets the stream type or null if no type was set.

Returns:

the type

beforeStreaming

protected void beforeStreaming()

Invoked just before steaming begins, in a new thread. Default implementation does nothing. This method is for implementors.

afterStreaming

protected void afterStreaming()

Invoked just after steaming ended, before the thread dies. Default implementation does nothing. This method is for implementors.

startAndWait

public void startAndWait()

Starts this consumer thread and wait for it to complete before returning.

Throws:

StreamException - if streaming is interrupted while waiting

consume

public static void consume(InputStream input)

Convenience method for creasing a consumer instance and starting it.

Parameters:

input - input stream to consume.

consume

public static void consume(InputStream input,
                           String type,
                           IInputStreamListener... listeners)

Convenience method for creasing a consumer instance and starting it.

Parameters:

input - input stream

type - an optional way to identify each portion being read to stream listeners. Useful when listeners are shared. Can be null.

listeners - input stream listeners

consume

public static void consume(InputStream input,
                           int chunkSize,
                           String type,
                           IInputStreamListener... listeners)

Convenience method for creasing a consumer instance, starting it, and waiting for it to complete.

Parameters:

input - input stream

chunkSize - how many bytes to read at once before (will also be the maximum byte array size sent to listeners)

type - an optional way to identify each portion being read to stream listeners. Useful when listeners are shared. Can be null.

listeners - input stream listeners

consumeAndWait

public static void consumeAndWait(InputStream input)

Convenience method for creasing a consumer instance, starting it, and waiting for it to complete.

Parameters:

input - input stream to consume.

consumeAndWait

public static void consumeAndWait(InputStream input,
                                  String type,
                                  IInputStreamListener... listeners)

Convenience method for creasing a consumer instance and starting it.

Parameters:

input - input stream

type - an optional way to identify each portion being read to stream listeners. Useful when listeners are shared. Can be null.

listeners - input stream listeners

consumeAndWait

public static void consumeAndWait(InputStream input,
                                  int chunkSize,
                                  String type,
                                  IInputStreamListener... listeners)

Convenience method for creasing a consumer instance, starting it, and waiting for it to complete.

Parameters:

input - input stream

chunkSize - how many bytes to read at once before (will also be the maximum byte array size sent to listeners)

type - an optional way to identify each portion being read to stream listeners. Useful when listeners are shared. Can be null.

listeners - input stream listeners