Class ThreadManager

java.lang.Object
  |
  +--ThreadManager

class ThreadManager

extends java.lang.Object

Manager for the threads. Every threads is used for a connection for downloading a part of the ressource.

Field Summary

(package private) static int	activeThreads
(package private) static int	existingThreads
private int	maxSpareThreads
private int	maxThreads
private int	minSpareThreads
private int	minThreads

Constructor Summary

ThreadManager()
Creates a new ThreadManager with default values as attributs. maxThreads = 50; minThreads = 5; maxSpareThreads = 5; minSpareThreads = 5; It doesn't create new Threads.

ThreadManager(int maxThreads, int minThreads, int maxSpareThreads, int minSpareThreads)
It sets the bounds for the Threads, but it doesn't create new Threads.

Method Summary

void	initialize(java.lang.Class runnableClass) Method that creates minThreads Threads
boolean	mustCreateThread() This method return true if a new Thread must be created
boolean	mustDestroyThread() This method return true if an existing Thread must be destroyed
void	newThread(java.lang.Class runnableClass) Method that creates a new Thread, starts it and update attributs of the ThreadManager.
void	oneLessActiveThread() This method decrements the number of activated Threads Attention!!
void	oneLessExistingThread() This method decrements the number of existing Threads Attention!!
void	oneMoreActiveThread() This method increments the number of activated Threads Attention!!
java.lang.String	printStatus() This method returns a String describing the number of existing and activated Threads.
void	setAttributs(int maxThreads, int minThreads, int maxSpareThreads, int minSpareThreads) This method changes the bounds for the number of Threads

Methods inherited from class java.lang.Object

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

Field Detail

maxThreads

private int maxThreads

minThreads

private int minThreads

maxSpareThreads

private int maxSpareThreads

minSpareThreads

private int minSpareThreads

existingThreads

static int existingThreads

activeThreads

static int activeThreads

Constructor Detail

ThreadManager

public ThreadManager()

Creates a new ThreadManager with default values as attributs. maxThreads = 50; minThreads = 5; maxSpareThreads = 5; minSpareThreads = 5; It doesn't create new Threads. Threads must be created using the initialize() method.

ThreadManager

public ThreadManager(int maxThreads,
                     int minThreads,
                     int maxSpareThreads,
                     int minSpareThreads)
              throws IllegalValuesException

It sets the bounds for the Threads, but it doesn't create new Threads. Threads must be created using the initialize() method.

Parameters:

maxThreads - maximum number of existing Threads

minThreads - minimum number of existing Threads

maxSpareThreads - maximum number of disactivated Threads

minSpareThreads - minimum number of disactivated Threads

Method Detail

initialize

public void initialize(java.lang.Class runnableClass)
                throws java.lang.InstantiationException,
                       java.lang.IllegalAccessException

Method that creates minThreads Threads

Parameters:

c - Class extending Runnable, every new Thread manages a new object of this class

setAttributs

public void setAttributs(int maxThreads,
                         int minThreads,
                         int maxSpareThreads,
                         int minSpareThreads)
                  throws IllegalValuesException

This method changes the bounds for the number of Threads

Parameters:

maxThreads - new maximum number of existing Threads

minThreads - new minimum number of existing Threads

maxSpareThreads - new maximum number of disactivated Threads

minSpareThreads - new minimum number of disactivated Threads

Throws:

IllegalValuesException -

printStatus

public java.lang.String printStatus()

This method returns a String describing the number of existing and activated Threads.

Returns:

a String with number and status of threads

newThread

public void newThread(java.lang.Class runnableClass)
               throws java.lang.InstantiationException,
                      java.lang.IllegalAccessException

Method that creates a new Thread, starts it and update attributs of the ThreadManager.

Parameters:

objectRunnable - An object instance of Runnable, managed by a new Thread

Throws:

InstantiationException, - IllegalAccessException

oneMoreActiveThread

public void oneMoreActiveThread()

This method increments the number of activated Threads Attention!! It doesn't activate a Thread.

oneLessActiveThread

public void oneLessActiveThread()

This method decrements the number of activated Threads Attention!! It doesn't deactivate a Thread.

oneLessExistingThread

public void oneLessExistingThread()

This method decrements the number of existing Threads Attention!! It doesn't destroy a Thread.

mustCreateThread

public boolean mustCreateThread()

This method return true if a new Thread must be created

mustDestroyThread

public boolean mustDestroyThread()

This method return true if an existing Thread must be destroyed