命令：jstack -l pid

如果有线程有死锁，则如下显示：

“IdleRemover” daemon prio=10 tid=0x00007f6b2c148800 nid=0x11d7 waiting on condition [0x00007f6b222e1000]

   java.lang.Thread.State: TIMED_WAITING (parking)

 at sun.misc.Unsafe.park(Native Method)

 – parking to wait for  <0x0000000766888158> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)

 at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:226)

 at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2176)

 at org.jboss.jca.core.connectionmanager.pool.idle.IdleRemover$IdleRemoverRunner.run(IdleRemover.java:261)

 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)

 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)

 at java.lang.Thread.run(Thread.java:722)
   Locked ownable synchronizers:

 – <0x0000000765df4068> (a java.util.concurrent.ThreadPoolExecutor$Worker) “ConnectionValidator” daemon prio=10 tid=0x00007f6b3c06c000 nid=0x11d6 waiting on condition [0x00007f6b223e2000]

   java.lang.Thread.State: TIMED_WAITING (parking)

 at sun.misc.Unsafe.park(Native Method)

 – parking to wait for  <0x0000000766888368> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)

 at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:226)

 at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2176)

 at org.jboss.jca.core.connectionmanager.pool.validator.ConnectionValidator$ConnectionValidatorRunner.run(ConnectionValidator.java:263)

 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)

 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)

 at java.lang.Thread.run(Thread.java:722)
   Locked ownable synchronizers:

 – <0x000000076664a320> (a java.util.concurrent.ThreadPoolExecutor$Worker) 

定位出来以后就可以去排查环境资源或者业务代码逻辑了。