根据不同的场景,可以选择不同的拒绝策略,如果任务非常重要,线程池队列满了,可以交由调用者线程同步处理.
如果是一些不太重要日志,可以直接丢弃掉.
如果一些可以丢弃,但是又需要知道被丢弃了,可以使用ThreadPoolExecutor.AbortPolicy(),在异常处理中记录日志
/**
* laizhenwei 2018-1-1 12:46:02
*/
@Configuration
@EnableAsync
public class ExecutorConfig implements AsyncConfigurer { /**
* 替换默认线程池,线程队列满了以后交给调用者执行,也就是同步执行
* @return
*/
@Override
public Executor getAsyncExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(7);
executor.setMaxPoolSize(42);
executor.setQueueCapacity(11);
executor.setThreadNamePrefix("Executor-");
executor.setAllowCoreThreadTimeOut(false);
executor.setRejectedExecutionHandler( new ThreadPoolExecutor.CallerRunsPolicy());
executor.initialize();
return executor;
} /**
* 队列满了以后,抛弃任务,但是会抛出 rejectedExecution 如果不处理会中断线程
* @return
*/
@Bean
public Executor myExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(1);
executor.setMaxPoolSize(2);
executor.setQueueCapacity(20);
executor.setThreadNamePrefix("MyExecutor-");
executor.setAllowCoreThreadTimeOut(false);
executor.setRejectedExecutionHandler( new ThreadPoolExecutor.AbortPolicy());
executor.initialize();
return executor;
} /**
* 队列满了,直接丢弃当前任务,不抛出异常
* @return
*/
@Bean
public Executor myExecutor1() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(1);
executor.setMaxPoolSize(2);
executor.setQueueCapacity(20);
executor.setThreadNamePrefix("MyExecutor1-");
executor.setAllowCoreThreadTimeOut(false);
executor.setRejectedExecutionHandler( new ThreadPoolExecutor.DiscardPolicy());
executor.initialize();
return executor;
} /**
* 队列满了,丢弃最老的任务,不抛出异常
* @return
*/
@Bean
public Executor myExecutor2() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(1);
executor.setMaxPoolSize(2);
executor.setQueueCapacity(20);
executor.setThreadNamePrefix("MyExecutor2-");
executor.setAllowCoreThreadTimeOut(false);
executor.setRejectedExecutionHandler( new ThreadPoolExecutor.DiscardOldestPolicy());
executor.initialize();
return executor;
} @Override
public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
return new MyAsyncUncaughtExceptionHandler();
} public static class MyAsyncUncaughtExceptionHandler implements AsyncUncaughtExceptionHandler{
@Override
public void handleUncaughtException(Throwable throwable, Method method, Object... objects) {
System.out.println(throwable.getMessage());
}
} }
调用方式使用 value 是bean 的名称
@Async("myExecutor")如果异步处理的方法,涉及到jdbc事务,那么请先理解Spring事务的连接是保存在ThreadLocal中的原理,避免踩坑.