JUC--黑马|JUC并发编程 -- 正确处理线程池异常 JUC|线程池异常捕获|java

1. 正确处理线程池异常 1.1 如果不处理异常

示例代码:

package com.tian; import lombok.extern.slf4j.Slf4j; import java.util.concurrent.ExecutionException; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; @Slf4j(topic = "c.TestTimer") public class TestTimer {public static void main(String[] args) throws ExecutionException, InterruptedException {ScheduledExecutorService pool = Executors.newScheduledThreadPool(1); pool.schedule(() -> {log.debug("task1"); // 主动写一个异常 int i = 1 / 0; }, 1, TimeUnit.SECONDS); pool.schedule(() -> {log.debug("task2"); }, 1, TimeUnit.SECONDS); pool.schedule(() -> {log.debug("task3"); }, 1, TimeUnit.SECONDS); } }

运行结果:

程序不会抛出任何的异常信息，直接把里面的任务执行完了，我们都不知道里面有没有发生异常。这样显然是不好的，下面介绍2种捕获异常的方式

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1.2 try / catch 捕获异常

示例代码:

package com.tian; import lombok.extern.slf4j.Slf4j; import java.util.concurrent.ExecutionException; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; @Slf4j(topic = "c.TestTimer") public class TestTimer {public static void main(String[] args) throws ExecutionException, InterruptedException {ScheduledExecutorService pool = Executors.newScheduledThreadPool(1); pool.schedule(() -> {// 主动捕获异常 try {log.debug("task1"); // 主动写一个异常 int i = 1 / 0; } catch (Exception e) {log.debug("error: {}", e); } }, 1, TimeUnit.SECONDS); pool.schedule(() -> {log.debug("task2"); }, 1, TimeUnit.SECONDS); pool.schedule(() -> {log.debug("task3"); }, 1, TimeUnit.SECONDS); } }

运行结果:

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1.3 使用 Future

示例代码:

package com.tian; import lombok.extern.slf4j.Slf4j; import java.util.concurrent.ExecutionException; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; @Slf4j(topic = "c.TestTimer") public class TestTimer {public static void main(String[] args) throws ExecutionException, InterruptedException {ExecutorService pool = Executors.newFixedThreadPool(1); Future f = pool.submit(() -> {log.debug("task1"); // 主动抛出异常 int i = 1 / 0; return true; }); // 如果任务里面发生了异常则 get方法会返回异常信息 log.debug("result:{}", f.get()); } }