CODEWITHSUNDEEP
javaandroidmultithreading
SamRowley
SamRowley

Reputation: 3485

Get reference to Thread Object from its ID

How can I get reference to a Running Thread if I know the ID associated with that Thread?

e.g.

long threadID = 12342;
Thread thread = (What goes here?) getThreadFromId(threadID); //I know this is totally made up

Upvotes: 27

Views: 22220

Answers (2)

Muhammed Shakir Misarwala
Muhammed Shakir Misarwala

Reputation: 114

You can use following code in order to get the Thread Name (For e.g. I want to get names of Threads that are in deadlock )

ThreadMXBean threadMB = ManagementFactory.getThreadMXBean();
long threadIds[] = threadMB.findDeadlockedThreads();
for (long id : threadIds) {
     System.out.println("The deadLock Thread id is : " + id
                            + "  > "
                            +       
     threadMB.getThreadInfo(id).getThreadName());
}

Upvotes: -1

bestsss
bestsss

Reputation: 12056

You have 2 ways to do it. Both are quite simple:

  • Old way: get the root thread group you may access Thread.currentThread().getGroup()..getParent() in loop. and call enumerate(Thread[])

  • newer (slower though). for (Thread t : Thread.getAllStackTraces().keySet()) if (t.getId()==id)...

The first method has a small problem that due to a bug in ThreadGroup.destroy(), a ThreadGroup may not enumerate anything at all.

The second is slower and has a security flaw, though.

Upvotes: 19

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