打印Java程序的线程栈信息方式

打印Java程序的线程栈信息

jstack可以得知当前线程的运行情况

安装jstack等命令集，jstack是开发版本jdk的一部分，不是开发版的有可能找不到

yum install -y  java-1.8.0-openjdk-devel

查看要打印堆栈的java进程ID

jps -l

打印堆栈

sudo -u admin jstack pid  > jstack.txt

特别要注意的是jstack需要使用与进程一致的用户才能正确导出堆栈，否则会报错如下

Unable to open socket file: target process not responding or HotSpot VM not loaded

线程池异常堆栈的坑

import java.util.concurrent.*;
public class DivTask implements Runnable{
   int a,b;
   public DivTask(int a, int b) {
       this.a = a;
       this.b = b;
   }
   @Override
   public void run() {
       double re = a/b;
       System.out.println(re);
   }
   public static void main(String[] args) throws InterruptedException, ExecutionException {
//        ThreadPoolExecutor executor = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 0L, TimeUnit.SECONDS
//                , new SynchronousQueue<>());
       TraceThreadPoolExecutor executor = new TraceThreadPoolExecutor(0, Integer.MAX_VALUE, 0L, TimeUnit.SECONDS
               , new SynchronousQueue<>());  //扩展TraceThreadPoolExecutor
       for (int i = 0; i < 5; i++) {
           // executor.submit(new DivTask(100,i));
           //改进方式一：
           //Future re = executor.submit(new DivTask(100, i));
           //re.get();
           //改进方式二：
           executor.execute(new DivTask(100,i));
       }
       //100.0
       //25.0
       //33.0
       //50.0
       //其中100/0的异常结果没打印
       //线程池很有可能"吃掉程序抛出的异常
       //改进方式一：
       //Exception in thread "main" java.util.concurrent.ExecutionException: java.lang.ArithmeticException: / by zero
       //at java.util.concurrent.FutureTask.report(FutureTask.java:122)
       //at java.util.concurrent.FutureTask.get(FutureTask.java:192)
       //。。。
       //改进方式二：
       //Exception in thread "pool-1-thread-1" java.lang.ArithmeticException: / by zero
       //at com.Test.DivTask.run(DivTask.java:15)
       //at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
       //at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
       //at java.lang.Thread.run(Thread.java:748)
       //100.0
       //33.0
       //25.0
       //50.0
       //扩展TraceThreadPoolExecutor
       //java.lang.Exception: Client stack trace
       //at com.Test.TraceThreadPoolExecutor.clientTrace(TraceThreadPoolExecutor.java:20)
       //at com.Test.TraceThreadPoolExecutor.execute(TraceThreadPoolExecutor.java:12)
       //at com.Test.DivTask.main(DivTask.java:29)
       //Exception in thread "pool-1-thread-1" java.lang.ArithmeticException: / by zero
       //at com.Test.DivTask.run(DivTask.java:15)
       //at com.Test.TraceThreadPoolExecutor.lambda$wrap$0(TraceThreadPoolExecutor.java:25)
       //at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
       //at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
       //at java.lang.Thread.run(Thread.java:748)
       //100.0
       //25.0
       //33.0
       //50.0
   }
}

import java.util.concurrent.*;
/**
* 扩展TraceThreadPoolExecutor，让它在调度任务前先保存一下提交任务线程的堆栈信息
*/
public class TraceThreadPoolExecutor extends ThreadPoolExecutor {
   public TraceThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue) {
       super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue);
   }
   @Override
   public void execute(Runnable task) {
       super.execute(wrap(task,clientTrace(),Thread.currentThread().getName()));
   }
   @Override
   public Future<?> submit(Runnable task) {
       return super.submit(wrap(task,clientTrace(),Thread.currentThread().getName()));
   }
   private Exception clientTrace(){
       return new Exception("Client stack trace");
   }
   private Runnable wrap(final Runnable task,final Exception clientTrace,String clientThreadName){
       return () -> {
           try {
               task.run();
           } catch (Exception e) {
               clientTrace.printStackTrace();
               throw e;
           }
       };
   }
}

来源：https://blog.csdn.net/x356982611/article/details/96147628