js.lang

Class AbstractLooper

java.lang.Object

js.lang.AbstractLooper

All Implemented Interfaces:

Looper, ManagedLifeCycle, ManagedPostConstruct, ManagedPreDestroy

public abstract class AbstractLooper
extends Object
implements ManagedLifeCycle, Looper

Base looper implementation takes care of looper thread life cycle. Concrete looper extending this abstract class should implement only the actual loop iteration logic. Both continuous and periodic modes are supported; see LooperThread for details.

In sample code Processor uses a user defined iteration period. It is also possible to run into continuous mode in which case Looper.loop() should wait for some IO events or explicit sleep.

 public class Processor extends AbstractLooper
 {
   public Processor()
   {
     super(PERIOD);
   }
 
   @Override
   public void loop() throws IOException
   {
     // implements loop iteration logic
   }
 }
 

Version:

final

Author:

Iulian Rotaru

Field Summary

Fields

Modifier and Type	Field and Description
protected LooperThread	thread Looper thread created, started and stopped by this abstract looper.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractLooper() Construct a looper instance operating in continuous modes.
protected	AbstractLooper(int period) Construct a looper instance operation in periodic mode.

Method Summary

Modifier and Type	Method and Description
void	postConstruct() Start looper thread.
void	preDestroy() Stop looper thread.

Methods inherited from class java.lang.Object

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

Methods inherited from interface js.lang.Looper

loop

Field Detail

thread

protected final LooperThread thread

Looper thread created, started and stopped by this abstract looper.

Constructor Detail

AbstractLooper

protected AbstractLooper()

Construct a looper instance operating in continuous modes. Looper.loop() implementation should wait for some IO events or explicit sleep to avoid abusing the thread.

AbstractLooper

protected AbstractLooper(int period)

Construct a looper instance operation in periodic mode.

Parameters:

period - loop iteration period, in milliseconds.

Throws:

IllegalArgumentException - if period argument is not strict positive.

Method Detail

postConstruct

public void postConstruct()
                   throws Exception

Start looper thread. This post-construct hook just starts this looper thread. Subclass may need to add application specific initialization and override this method but should explicitly invoke super. Otherwise looper thread is not started.

Specified by:

postConstruct in interface ManagedLifeCycle

Specified by:

postConstruct in interface ManagedPostConstruct

Throws:

Exception - exceptions from application defined post-construct logic are bubbled up.

preDestroy

public void preDestroy()
                throws Exception

Stop looper thread. This pre-destroy hook just stops this looper thread. Subclass may need to defined specific clean-up logic. It can override this hook but should explicitly invoke super. Otherwise looper thread is not stopped and runs indefinitely.

Specified by:

preDestroy in interface ManagedLifeCycle

Specified by:

preDestroy in interface ManagedPreDestroy

Throws:

Exception - exceptions from application defined clean-up logic are bubbled up.