com.cloudhopper.commons.util

Class ThreadUtil

java.lang.Object

com.cloudhopper.commons.util.ThreadUtil

public class ThreadUtil
extends Object

A utility class for working with threads in a JVM. Some of these methods were obtained here: http://nadeausoftware.com/articles/2008/04/java_tip_how_list_and_find_threads_and_thread_groups#Gettingalistofallthreads

Author:

joelauer (twitter: @jjlauer or http://twitter.com/jjlauer)

Constructor Summary

Constructors

Constructor and Description
ThreadUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static Thread[]	getAllThreads() Gets all threads in the JVM.
static Thread[]	getAllThreadsMatching(String regex) Gets all threads if its name matches a regular expression.
static ThreadGroup	getRootThreadGroup() Gets the "root" thread group for the entire JVM.
static Thread	getThread(long id) Gets a thread by its assigned ID.

Methods inherited from class java.lang.Object

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

Constructor Detail

ThreadUtil

public ThreadUtil()

Method Detail

getRootThreadGroup

public static ThreadGroup getRootThreadGroup()

Gets the "root" thread group for the entire JVM. Internally, first get the current thread and its thread group. Then get its parent group, then its parent group, and on up until you find a group with a null parent. That's the root ThreadGroup. Since the same root thread group is used for the life of the JVM, you can safely cache it for faster future use.

Returns:

The root thread group for the JVM

getAllThreads

public static Thread[] getAllThreads()

Gets all threads in the JVM. This is really a snapshot of all threads at the time this method is called.

Returns:

An array of all threads currently running in the JVM.

getThread

public static Thread getThread(long id)

Gets a thread by its assigned ID. Internally, this method calls getAllThreads() so be careful to only call this method once and cache your result.

Parameters:

id - The thread ID

Returns:

The thread with this ID or null if none were found

getAllThreadsMatching

public static Thread[] getAllThreadsMatching(String regex)

Gets all threads if its name matches a regular expression. For example, using a regex of "main" will execute a case-sensitive match for threads with the exact name of "main". A regex of ".*main.*" will execute a case sensitive match for threads with "main" anywhere in their name. A regex of "(?i).*main.*" will execute a case insensitive match of any thread that has "main" in its name.

Parameters:

regex - The regular expression to use when matching a threads name. Same rules apply as String.matches() method.

Returns:

An array (will not be null) of all matching threads. An empty array will be returned if no threads match.