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;
            }
        };
    }
}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。