Java多线程——查看线程堆栈信息

Java多线程——查看线程堆栈信息

摘要：本文主要介绍了查看线程堆栈信息的方法。

使用Thread类的getAllStackTraces()方法

方法定义

可以看到getAllStackTraces()方法的返回值是一个Map对象，key是Thread的实例，value是一个StackTraceElement实例数组：

 public static Map<Thread, StackTraceElement[]> getAllStackTraces()

使用

可以使用这个静态方法在页面上循环打印，从而获取到运行时的堆栈情况：

 <body>
     <%
     StringBuilder sb = new StringBuilder();
     Map<Thread, StackTraceElement[]> ts = Thread.getAllStackTraces();
     for (Thread t : ts.keySet()) {
         StackTraceElement[] s = ts.get(t);
         sb.append(t.getName() + ":" + t.getId()).append("<br>");
         for (StackTraceElement e : s) {
             sb.append("&emsp;").append(e).append("<br>");
         }
     }
     out.print(sb.toString());
     %>
 </body>

页面显示

在页面上显示如下：

 Reference Handler:2
     java.lang.Object.wait(Native Method)
     java.lang.Object.wait(Object.java:502)
     java.lang.ref.Reference.tryHandlePending(Reference.java:191)
     java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)
 Signal Dispatcher:4
 SockJS-5:40
     sun.misc.Unsafe.park(Native Method)
     java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
     java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
     java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1088)
     java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:809)
     java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
     java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
     java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
     java.lang.Thread.run(Thread.java:745)
 ContainerBackgroundProcessor[StandardEngine[Tomcat]]:27
     java.lang.Thread.sleep(Native Method)
     org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1368)
     java.lang.Thread.run(Thread.java:745)
 C3P0PooledConnectionPoolManager[identityToken->1hge7sxa31d0rqyw19bxvtp|1e774dd6]-AdminTaskTimer:22
     java.lang.Object.wait(Native Method)
     java.util.TimerThread.mainLoop(Timer.java:552)
     java.util.TimerThread.run(Timer.java:505)
 SockJS-4:39
     sun.misc.Unsafe.park(Native Method)
     java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
     java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
     java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1088)
     java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:809)
     java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
     java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
     java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
     java.lang.Thread.run(Thread.java:745)
 C3P0PooledConnectionPoolManager[identityToken->1hge7sxa31d0rqyw19bxvtp|1084583d]-HelperThread-#2:63
     java.lang.Object.wait(Native Method)
     com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:683)