多线程线程池异常处理

不念不忘少年蓝@ 2023-07-17 02:45 18阅读 0赞

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### 多线程 线程池异常处理 ###

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**示例：线程池执行过程中异常不输出，及解决方法测试**

public class MyTest {
    
        public static Runnable run(){
            return ()->System.out.println("2/0="+2/0);
        }
    
        public static Runnable run2(){
            return ()-> {
                try {
                    System.out.println("2/0="+2/0);
                }catch (Exception e){
                    e.printStackTrace();
                }
            };
        }
    
        public static void fun(){
            ExecutorService executorService= Executors.newFixedThreadPool(5);
            executorService.execute(run());
            executorService.execute(run2());
    
            executorService.shutdown();
        }
    
        public static void fun2(){
            ExecutorService executorService= Executors.newFixedThreadPool(5);
            executorService.submit(run());
            executorService.submit(run2());
    
            executorService.shutdown();
        }
    
        public static void fun3(){
            ExecutorService executorService=new ThreadPoolExecutor(5,5,20, TimeUnit.SECONDS,
                    new ArrayBlockingQueue<Runnable>(10)){
    
                @Override
                public void execute(Runnable command) {
                    try {
                        super.execute(command);
                    }catch (Exception e){
                        e.printStackTrace();
                    }
                }
            };
    
            executorService.execute(run());
            executorService.execute(run2());
    
            executorService.shutdown();
        }
    
        public static void fun4(){
            ExecutorService executorService=new ThreadPoolExecutor(5,5,10L,TimeUnit.SECONDS,
                    new ArrayBlockingQueue<>(10)){
    
                @Override
                public Future<?> submit(Runnable task) {
                    return super.submit(()->{
                        try{
                            task.run();
                        }catch (Exception e){
                            e.printStackTrace();
                        }
                    });
                }
            };
    
            executorService.submit(run());
            executorService.submit(run2());
        }
    
        public static void fun5(){
            ExecutorService executorService=new ThreadPoolExecutor(5,5,10l,TimeUnit.SECONDS,
                    new ArrayBlockingQueue<>(10)){
    
                @Override
                protected void afterExecute(Runnable r, Throwable t) {
                    super.afterExecute(r, t);
    
                    if (t!=null){
                        System.out.println("afterExecute："+t.getMessage());
                    }
                }
            };
    
            executorService.execute(run());
            executorService.execute(run2());
    
            executorService.shutdown();
        }
    
        public static void fun6(){
            ExecutorService executorService=new ThreadPoolExecutor(5,5,10l,TimeUnit.SECONDS,
                    new ArrayBlockingQueue<>(10)){
    
                @Override
                protected void afterExecute(Runnable r, Throwable t) {
                    super.afterExecute(r, t);
    
                    if (t!=null){
                        System.out.println("afterExecute："+t.getMessage());
                    }
                }
            };
    
            executorService.submit(run());
            executorService.submit(run2());
    
            executorService.shutdown();
        }
    
        public static void main(String[] args){
            fun();
            //fun2();
            //fun3();
            //fun4();
            //fun5();
            //fun6();
        }
    }

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**相关输出**

**fun()**

Exception in thread "pool-1-thread-1" java.lang.ArithmeticException: / by zero
    	at threadtest.MyTest.lambda$run$0(MyTest.java:8)
    	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    	at java.base/java.lang.Thread.run(Thread.java:835)
    java.lang.ArithmeticException: / by zero
    	at threadtest.MyTest.lambda$run2$1(MyTest.java:14)
    	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    	at java.base/java.lang.Thread.run(Thread.java:835)

**说明：同步执行（execute）时，run()、run2()方法异常都有输出**

**fun2()**

java.lang.ArithmeticException: / by zero
    	at threadtest.MyTest.lambda$run2$1(MyTest.java:14)
    	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
    	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    	at java.base/java.lang.Thread.run(Thread.java:835)

**说明：异步执行（submit）时，run()方法不输出运行时异常、run2()方法使用try-catch语句块输出异常信息**

**fun3()**

**说明：自定义线程池，重载execute方法，与未重载execute方法执行输出一致**

**fun4()**

java.lang.ArithmeticException: / by zero
    	at threadtest.MyTest.lambda$run$0(MyTest.java:8)
    	at threadtest.MyTest$2.lambda$submit$0(MyTest.java:65)
    	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
    	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    	at java.base/java.lang.Thread.run(Thread.java:835)
    java.lang.ArithmeticException: / by zero
    	at threadtest.MyTest.lambda$run2$1(MyTest.java:14)
    	at threadtest.MyTest$2.lambda$submit$0(MyTest.java:65)
    	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
    	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    	at java.base/java.lang.Thread.run(Thread.java:835)

**说明：自定义线程池，重载submit方法，run()、run2()方法都输出异常信息**

**fun5()**

java.lang.ArithmeticException: / by zero
    	at threadtest.MyTest.lambda$run2$1(MyTest.java:14)
    	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    	at java.base/java.lang.Thread.run(Thread.java:835)
    afterExecute：/ by zero
    Exception in thread "pool-1-thread-1" java.lang.ArithmeticException: / by zero
    	at threadtest.MyTest.lambda$run$0(MyTest.java:8)
    	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    	at java.base/java.lang.Thread.run(Thread.java:835)

**说明： 重载afterExecute方法，同步执行，****run()输出并抛出异常，抛出的异常由afterExecute输出；****run2()输出异常，无异常信息抛出**

**fun6()**

**说明：重载afterExecute方法不能处理submit执行过程中的异常**

**总结：execute方法异常不需要处理可直接输出；submit使用try-catch语句块处理异常，**

**或者重载线程池ThreadPoolExecutor中的submit方法**