Spring Boot利用@Async异步调用:ThreadPoolTaskScheduler线程池
前言 之前分享了一篇关于Spring Boot中使用@Async来实现异步任务和线程池控制的文章:《Spring Boot使用@Async实现异步调用:自定义线程池》。由于最近身边也发现了不少异步任务没有正确处理而导致的不少问题,所以在本文就接前面内容,继续说说线程池的优雅关闭,主要针对ThreadPoolTaskScheduler线程池。 问题现象 在上篇文章的例子Chapter4-1-3中,我们定义了一个线程池,然后利用@Async注解写了3个任务,并指定了这些任务执行使用的线程池。在上文的单元测试中,我们没有具体说说shutdown相关的问题,下面我们就来模拟一个问题现场出来。 第一步:如前文一样,我们定义一个ThreadPoolTaskScheduler线程池: @SpringBootApplication public class Application { public static void main(String[] args) { SpringApplication.run(Application.class,args); } @EnableAsync @Configuration class TaskPoolConfig { @Bean("taskExecutor") public Executor taskExecutor() { ThreadPoolTaskScheduler executor = new ThreadPoolTaskScheduler(); executor.setPoolSize(20); executor.setThreadNamePrefix("taskExecutor-"); return executor; } } } 第二步:改造之前的异步任务,让它依赖一个外部资源,比如:Redis @Slf4j @Component public class Task { @Autowired private StringRedisTemplate stringRedisTemplate; @Async("taskExecutor") public void doTaskOne() throws Exception { log.info("开始做任务一"); long start = System.currentTimeMillis(); log.info(stringRedisTemplate.randomKey()); long end = System.currentTimeMillis(); log.info("完成任务一,耗时:" + (end - start) + "毫秒"); } @Async("taskExecutor") public void doTaskTwo() throws Exception { log.info("开始做任务二"); long start = System.currentTimeMillis(); log.info(stringRedisTemplate.randomKey()); long end = System.currentTimeMillis(); log.info("完成任务二,耗时:" + (end - start) + "毫秒"); } @Async("taskExecutor") public void doTaskThree() throws Exception { log.info("开始做任务三"); long start = System.currentTimeMillis(); log.info(stringRedisTemplate.randomKey()); long end = System.currentTimeMillis(); log.info("完成任务三,耗时:" + (end - start) + "毫秒"); } } 注意:这里省略了pom.xml中引入依赖和配置redis的步骤 第三步:修改单元测试,模拟高并发情况下ShutDown的情况: @RunWith(SpringJUnit4ClassRunner.class) @SpringBootTest public class ApplicationTests { @Autowired private Task task; @Test @SneakyThrows public void test() { for (int i = 0; i < 10000; i++) { task.doTaskOne(); task.doTaskTwo(); task.doTaskThree(); if (i == 9999) { System.exit(0); } } } } 说明:通过for循环往上面定义的线程池中提交任务,由于是异步执行,在执行过程中,利用System.exit(0)来关闭程序,此时由于有任务在执行,就可以观察这些异步任务的销毁与Spring容器中其他资源的顺序是否安全。 第四步:运行上面的单元测试,我们将碰到下面的异常内容。 org.springframework.data.redis.RedisConnectionFailureException: Cannot get Jedis connection; nested exception is redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.fetchJedisConnector(JedisConnectionFactory.java:204) ~[spring-data-redis-1.8.10.RELEASE.jar:na] at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.getConnection(JedisConnectionFactory.java:348) ~[spring-data-redis-1.8.10.RELEASE.jar:na] at org.springframework.data.redis.core.RedisConnectionUtils.doGetConnection(RedisConnectionUtils.java:129) ~[spring-data-redis-1.8.10.RELEASE.jar:na] at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:92) ~[spring-data-redis-1.8.10.RELEASE.jar:na] at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:79) ~[spring-data-redis-1.8.10.RELEASE.jar:na] at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:194) ~[spring-data-redis-1.8.10.RELEASE.jar:na] at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:169) ~[spring-data-redis-1.8.10.RELEASE.jar:na] at org.springframework.data.redis.core.RedisTemplate.randomKey(RedisTemplate.java:781) ~[spring-data-redis-1.8.10.RELEASE.jar:na] at com.didispace.async.Task.doTaskOne(Task.java:26) ~[classes/:na] at com.didispace.async.Task$$FastClassBySpringCGLIB$$ca3ff9d6.invoke(<generated>) ~[classes/:na] at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738) ~[spring-aop-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) ~[spring-aop-4.3.14.RELEASE.jar:4.3.14.RELEASE] at org.springframework.aop.interceptor.AsyncExecutionInterceptor$1.call(AsyncExecutionInterceptor.java:115) ~[spring-aop-4.3.14.RELEASE.jar:4.3.14.RELEASE] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_151] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_151] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) [na:1.8.0_151] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_151] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_151] at java.lang.Thread.run(Thread.java:748) [na:1.8.0_151] Caused by: redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool at redis.clients.util.Pool.getResource(Pool.java:53) ~[jedis-2.9.0.jar:na] at redis.clients.jedis.JedisPool.getResource(JedisPool.java:226) ~[jedis-2.9.0.jar:na] at redis.clients.jedis.JedisPool.getResource(JedisPool.java:16) ~[jedis-2.9.0.jar:na] at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.fetchJedisConnector(JedisConnectionFactory.java:194) ~[spring-data-redis-1.8.10.RELEASE.jar:na] ... 19 common frames omitted Caused by: java.lang.InterruptedException: null at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.reportInterruptAfterWait(AbstractQueuedSynchronizer.java:2014) ~[na:1.8.0_151] at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2088) ~[na:1.8.0_151] at org.apache.commons.pool2.impl.LinkedBlockingDeque.pollFirst(LinkedBlockingDeque.java:635) ~[commons-pool2-2.4.3.jar:2.4.3] at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:442) ~[commons-pool2-2.4.3.jar:2.4.3] at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:361) ~[commons-pool2-2.4.3.jar:2.4.3] at redis.clients.util.Pool.getResource(Pool.java:49) ~[jedis-2.9.0.jar:na] ... 22 common frames omitted 如何解决 原因分析 从异常信 解决方法 要解决上面的问题很简单,Spring的ThreadPoolTaskScheduler为我们提供了相关的配置,只需要加入如下设置即可: @Bean("taskExecutor") public Executor taskExecutor() { ThreadPoolTaskScheduler executor = new ThreadPoolTaskScheduler(); executor.setPoolSize(20); executor.setThreadNamePrefix("taskExecutor-"); executor.setWaitForTasksToCompleteOnShutdown(true); executor.setAwaitTerminationSeconds(60); return executor; } 说明: 完整示例: 读者可以根据喜好选择下面的两个仓库中查看Chapter4-1-4项目: Github:https://github.com/dyc87112/SpringBoot-Learning/ Gitee:https://gitee.com/didispace/SpringBoot-Learning/ 本地下载:http://xiazai.aspzz.cn/201805/yuanma/SpringBoot-Learning(aspzz.cn).rar 总结 以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作具有一定的参考学习价值,如果有疑问大家可以留言交流,谢谢大家对编程小技巧的支持。 您可能感兴趣的文章:
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