org.jnetpcap
Class PcapTask<T>

java.lang.Object
  org.jnetpcap.PcapTask<T>

Type Parameters:

T - user supplied type start() and stop(). These 2 methods perform various synchronization functions between the worker and the parent threads.

All Implemented Interfaces:

java.lang.Runnable

public abstract class PcapTask<T>
extends java.lang.Object
implements java.lang.Runnable

A pcap background task handle. This provides status and control over the background loop. The task provides 2 methods for controlling the thread.

Since:

1.2

Author:

Mark Bednarczyk, Sly Technologies, Inc.

Field Summary

protected int	count Number of packets to capture or 0 for infinate.
protected Pcap	pcap Pcap handle.
protected int	result Libpcap result code.
protected java.lang.Thread	thread Controlling thread.
protected T	user User data.

Constructor Summary

PcapTask(Pcap pcap, int count, T user)
Creates a new task handle for controlling background thread.

Method Summary

protected void	breakLoop() Algorithm for breaking the loop, whatever it is.
int	getCount() The packet count that was supplied by the user.
Pcap	getPcap() Returns the underlying Pcap object being used by this task
int	getResult() Returns the result code that was returned from the user supplied pcap function.
java.lang.Thread	getThread() Gets the background thread this task is using.
T	getUser() User supplied data object.
boolean	isAlive() Checks if the background thread is running and is alive.
void	start() Creates and starts up the background thread while synchronizing with the background thread.
void	stop() Terminates the task after making sure that the pcap session and thread are active.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Runnable

run

Field Detail

result

protected int result

Libpcap result code.

thread

protected java.lang.Thread thread

Controlling thread.

pcap

protected final Pcap pcap

Pcap handle.

count

protected final int count

Number of packets to capture or 0 for infinate.

user

protected final T user

User data.

Constructor Detail

PcapTask

public PcapTask(Pcap pcap,
                int count,
                T user)

Creates a new task handle for controlling background thread.

Parameters:

pcap - pcap handle

count - number of packets to capture or 0 for infinite

user - user supplied object

Method Detail

getResult

public final int getResult()

Returns the result code that was returned from the user supplied pcap function.

Returns:

libpcap result code

getThread

public final java.lang.Thread getThread()

Gets the background thread this task is using. It is highly recommended though that the user interact with the thread using start() and

Returns:

background thread stop() methods.

start

public void start()
           throws java.lang.InterruptedException

Creates and starts up the background thread while synchronizing with the background thread. The user can be assured that when this method returns, the background thread has been started and has entered its Runnable.run method.

Throws:

java.lang.InterruptedException - if the synchronization between threads was interrupted

stop

public void stop()
          throws java.lang.InterruptedException

Terminates the task after making sure that the pcap session and thread are active.

Throws:

java.lang.InterruptedException - since this method waits for the background thread to terminate, it can be interrupted

breakLoop

protected void breakLoop()

Algorithm for breaking the loop, whatever it is. It can be overriden and a different algorithm supplied.

isAlive

public boolean isAlive()

Checks if the background thread is running and is alive.

Returns:

true means thread is alive

getPcap

public final Pcap getPcap()

Returns the underlying Pcap object being used by this task

Returns:

pcap capture session object

getCount

public final int getCount()

The packet count that was supplied by the user. This is the number of packets requested by the user. 0 indicates capture forever until

Returns:

number of packets to capture or 0 for infinite stop() is called or an error occures.

getUser

public final T getUser()

User supplied data object. This is an arbitrary user object.

Returns:

user object