本文介绍了Spring @Async异步线程池用法总结，分享给大家，希望对大家有帮助

1. TaskExecutor

spring异步线程池的接口类，其实质是Java.util.concurrent.Executor

Spring 已经实现的异常线程池：

1. SimpleAsyncTaskExecutor：不是真的线程池，这个类不重用线程，每次调用都会创建一个新的线程。
2. SyncTaskExecutor：这个类没有实现异步调用，只是一个同步操作。只适用于不需要多线程的地方
3. ConcurrentTaskExecutor：Executor的适配类，不推荐使用。如果ThreadPoolTaskExecutor不满足要求时，才用考虑使用这个类
4. SimpleThreadPoolTaskExecutor：是Quartz的SimpleThreadPool的类。线程池同时被quartz和非quartz使用，才需要使用此类
5. ThreadPoolTaskExecutor ：最常使用，推荐。 其实质是对java.util.concurrent.ThreadPoolExecutor的包装

2. @Async

spring对过@Async定义异步任务

异步的方法有3种

1. 最简单的异步调用，返回值为void
2. 带参数的异步调用 异步方法可以传入参数
3. 异常调用返回Future

详细见代码：

@Component
public class AsyncDemo {
  private static final Logger log = LoggerFactory.getLogger(AsyncDemo.class);

  /**
   * 最简单的异步调用，返回值为void
   */
  @Async
  public void asyncInvokeSimplest() {
    log.info("asyncSimplest");
  }

  /**
   * 带参数的异步调用 异步方法可以传入参数
   * 
   * @param s
   */
  @Async
  public void asyncInvokeWithParameter(String s) {
    log.info("asyncInvokeWithParameter, parementer={}", s);
  }

  /**
   * 异常调用返回Future
   * 
   * @param i
   * @return
   */
  @Async
  public Future<String> asyncInvokeReturnFuture(int i) {
    log.info("asyncInvokeReturnFuture, parementer={}", i);
    Future<String> future;
    try {
      Thread.sleep(1000 * 1);
      future = new AsyncResult<String>("success:" + i);
    } catch (InterruptedException e) {
      future = new AsyncResult<String>("error");
    }
    return future;
  }

}

以上的异步方法和普通的方法调用相同

asyncDemo.asyncInvokeSimplest();
asyncDemo.asyncInvokeWithException("test");
Future<String> future = asyncDemo.asyncInvokeReturnFuture(100);
System.out.println(future.get());

3. Spring 开启异步配置

Spring有两种方法启动配置

1. 注解
2. XML

3.1 通过注解实现

要启动异常方法还需要以下配置

1. @EnableAsync 此注解开户异步调用功能

2. public AsyncTaskExecutor taskExecutor() 方法自定义自己的线程池，线程池前缀”Anno-Executor”。如果不定义，则使用系统默认的线程池。

@SpringBootApplication
@EnableAsync // 启动异步调用
public class AsyncApplicationWithAnnotation {
  private static final Logger log = LoggerFactory.getLogger(AsyncApplicationWithAnnotation.class);

  /**
   * 自定义异步线程池
   * @return
   */
  @Bean
  public AsyncTaskExecutor taskExecutor() { 
    ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor(); 
    executor.setThreadNamePrefix("Anno-Executor");
    executor.setMaxPoolSize(10); 

    // 设置拒绝策略
    executor.setRejectedExecutionHandler(new RejectedExecutionHandler() {
      @Override
      public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
        // .....
      }
    });
    // 使用预定义的异常处理类
    // executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());

    return executor; 
  } 

  public static void main(String[] args) {
    log.info("Start AsyncApplication.. ");
    SpringApplication.run(AsyncApplicationWithAnnotation.class, args);
  }
}

以上的异常方法和普通的方法调用相同

@RunWith(SpringRunner.class)
@SpringBootTest(classes=AsyncApplicationWithAnnotation.class)
public class AsyncApplicationWithAnnotationTests {
  @Autowired
  private AsyncDemo asyncDemo;

  @Test
  public void contextLoads() throws InterruptedException, ExecutionException {
    asyncDemo.asyncInvokeSimplest();
    asyncDemo.asyncInvokeWithParameter("test");
    Future<String> future = asyncDemo.asyncInvokeReturnFuture(100);
    System.out.println(future.get());
  }
}

执行测试用例，输出内容如下：

可以看出主线程的名称为main; 异步方法则使用 Anno-Executor1，可见异常线程池起作用了

2017-03-28 20:00:07.731 INFO 5144 --- [ Anno-Executor1] c.hry.spring.async.annotation.AsyncDemo : asyncSimplest
2017-03-28 20:00:07.732 INFO 5144 --- [ Anno-Executor1] c.hry.spring.async.annotation.AsyncDemo : asyncInvokeWithParameter, parementer=test
2017-03-28 20:00:07.751 INFO 5144 --- [ Anno-Executor1] c.hry.spring.async.annotation.AsyncDemo : asyncInvokeReturnFuture, parementer=100
success:100
2017-03-28 20:00:08.757 INFO 5144 --- [    Thread-2] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@47af7f3d: startup date [Tue Mar 28 20:00:06 CST 2017]; root of context hierarchy

3.2 通过XML实现

Bean文件配置: spring_async.xml

1. 线程的前缀为xmlExecutor
2. 启动异步线程池配置

  <!-- 等价于 @EnableAsync， executor指定线程池 -->
  <task:annotation-driven executor="xmlExecutor"/>
  <!-- id指定线程池产生线程名称的前缀 -->
  <task:executor
    id="xmlExecutor"
    pool-size="5-25"
    queue-capacity="100"
    keep-alive="120"
    rejection-policy="CALLER_RUNS"/>

线程池参数说明

1. ‘id' ： 线程的名称的前缀

2. ‘pool-size'：线程池的大小。支持范围”min-max”和固定值（此时线程池core和max sizes相同）

3. ‘queue-capacity' ：排队队列长度

○ The main idea is that when a task is submitted, the executor will first try to use a free thread if the number of active threads is currently less than the core size.
○ If the core size has been reached, then the task will be added to the queue as long as its capacity has not yet been reached.
○ Only then, if the queue's capacity has been reached, will the executor create a new thread beyond the core size.
○ If the max size has also been reached, then the executor will reject the task.
○ By default, the queue is unbounded, but this is rarely the desired configuration because it can lead to OutOfMemoryErrors if enough tasks are added to that queue while all pool threads are busy.

4. ‘rejection-policy': 对拒绝的任务处理策略

○ In the default ThreadPoolExecutor.AbortPolicy, the handler throws a runtime RejectedExecutionException upon rejection.
○ In ThreadPoolExecutor.CallerRunsPolicy, the thread that invokes execute itself runs the task. This provides a simple feedback control mechanism that will slow down the rate that new tasks are submitted.
○ In ThreadPoolExecutor.DiscardPolicy, a task that cannot be executed is simply dropped.
○ In ThreadPoolExecutor.DiscardOldestPolicy, if the executor is not shut down, the task at the head of the work queue is dropped, and then execution is retried (which can fail again, causing this to be repeated.)

5. ‘keep-alive' ： 线程保活时间（单位秒）

setting determines the time limit (in seconds) for which threads may remain idle before being terminated. If there are more than the core number of threads currently in the pool, after waiting this amount of time without processing a task, excess threads will get terminated. A time value of zero will cause excess threads to terminate immediately after executing a task without remaining follow-up work in the task queue()

异步线程池

@SpringBootApplication
@ImportResource("classpath:/async/spring_async.xml")
public class AsyncApplicationWithXML {
  private static final Logger log = LoggerFactory.getLogger(AsyncApplicationWithXML.class);

  public static void main(String[] args) {
    log.info("Start AsyncApplication.. ");
    SpringApplication.run(AsyncApplicationWithXML.class, args);
  }
}

测试用例

@RunWith(SpringRunner.class)
@SpringBootTest(classes=AsyncApplicationWithXML.class)
public class AsyncApplicationWithXMLTest {
  @Autowired
  private AsyncDemo asyncDemo;

  @Test
  public void contextLoads() throws InterruptedException, ExecutionException {
    asyncDemo.asyncInvokeSimplest();
    asyncDemo.asyncInvokeWithParameter("test");
    Future<String> future = asyncDemo.asyncInvokeReturnFuture(100);
    System.out.println(future.get());
  }
}

运行测试用例，输出内容如下：

可以看出主线程的名称为main; 异步方法则使用 xmlExecutor-x，可见异常线程池起作用了

2017-03-28 20:12:10.540 INFO 12948 --- [      main] c.h.s.a.xml.AsyncApplicationWithXMLTest : Started AsyncApplicationWithXMLTest in 1.441 seconds (JVM running for 2.201)
2017-03-28 20:12:10.718 INFO 12948 --- [ xmlExecutor-2] com.hry.spring.async.xml.AsyncDemo    : asyncInvokeWithParameter, parementer=test
2017-03-28 20:12:10.721 INFO 12948 --- [ xmlExecutor-1] com.hry.spring.async.xml.AsyncDemo    : asyncSimplest
2017-03-28 20:12:10.722 INFO 12948 --- [ xmlExecutor-3] com.hry.spring.async.xml.AsyncDemo    : asyncInvokeReturnFuture, parementer=100
success:100
2017-03-28 20:12:11.729 INFO 12948 --- [    Thread-2] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@71809907: startup date [Tue Mar 28 20:12:09 CST 2017]; root of context hierarchy

4. 对异步方法的异常处理

在调用方法时，可能出现方法中抛出异常的情况。在异步中主要有有两种异常处理方法：

1. 对于方法返回值是Futrue的异步方法: a) 一种是在调用future的get时捕获异常; b) 在异常方法中直接捕获异常

2. 对于返回值是void的异步方法：通过AsyncUncaughtExceptionHandler处理异常

AsyncExceptionDemo：

@Component
public class AsyncExceptionDemo {
  private static final Logger log = LoggerFactory.getLogger(AsyncExceptionDemo.class);

  /**
   * 最简单的异步调用，返回值为void
   */
  @Async
  public void asyncInvokeSimplest() {
    log.info("asyncSimplest");
  }

  /**
   * 带参数的异步调用 异步方法可以传入参数
   * 对于返回值是void，异常会被AsyncUncaughtExceptionHandler处理掉
   * @param s
   */
  @Async
  public void asyncInvokeWithException(String s) {
    log.info("asyncInvokeWithParameter, parementer={}", s);
    throw new IllegalArgumentException(s);
  }

  /**
   * 异常调用返回Future
   * 对于返回值是Future，不会被AsyncUncaughtExceptionHandler处理，需要我们在方法中捕获异常并处理
   * 或者在调用方在调用Futrue.get时捕获异常进行处理
   * 
   * @param i
   * @return
   */
  @Async
  public Future<String> asyncInvokeReturnFuture(int i) {
    log.info("asyncInvokeReturnFuture, parementer={}", i);
    Future<String> future;
    try {
      Thread.sleep(1000 * 1);
      future = new AsyncResult<String>("success:" + i);
      throw new IllegalArgumentException("a");
    } catch (InterruptedException e) {
      future = new AsyncResult<String>("error");
    } catch(IllegalArgumentException e){
      future = new AsyncResult<String>("error-IllegalArgumentException");
    }
    return future;
  }

}

实现AsyncConfigurer接口对异常线程池更加细粒度的控制

a) 创建线程自己的线程池

b) 对void方法抛出的异常处理的类AsyncUncaughtExceptionHandler

/**
 * 通过实现AsyncConfigurer自定义异常线程池，包含异常处理
 * 
 * @author hry
 *
 */
@Service
public class MyAsyncConfigurer implements AsyncConfigurer{
  private static final Logger log = LoggerFactory.getLogger(MyAsyncConfigurer.class);

  @Override
  public Executor getAsyncExecutor() {
    ThreadPoolTaskExecutor threadPool = new ThreadPoolTaskExecutor(); 
    threadPool.setCorePoolSize(1); 
    threadPool.setMaxPoolSize(1); 
    threadPool.setWaitForTasksToCompleteOnShutdown(true); 
    threadPool.setAwaitTerminationSeconds(60 * 15); 
    threadPool.setThreadNamePrefix("MyAsync-");
    threadPool.initialize();
    return threadPool; 
  }

  @Override
  public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
     return new MyAsyncExceptionHandler(); 
  }

  /**
   * 自定义异常处理类
   * @author hry
   *
   */
  class MyAsyncExceptionHandler implements AsyncUncaughtExceptionHandler { 

    @Override 
    public void handleUncaughtException(Throwable throwable, Method method, Object... obj) { 
      log.info("Exception message - " + throwable.getMessage()); 
      log.info("Method name - " + method.getName()); 
      for (Object param : obj) { 
        log.info("Parameter value - " + param); 
      } 
    } 

  } 

}

@SpringBootApplication
@EnableAsync // 启动异步调用
public class AsyncApplicationWithAsyncConfigurer {
  private static final Logger log = LoggerFactory.getLogger(AsyncApplicationWithAsyncConfigurer.class);

  public static void main(String[] args) {
    log.info("Start AsyncApplication.. ");
    SpringApplication.run(AsyncApplicationWithAsyncConfigurer.class, args);
  }


}

测试代码

@RunWith(SpringRunner.class)
@SpringBootTest(classes=AsyncApplicationWithAsyncConfigurer.class)
public class AsyncApplicationWithAsyncConfigurerTests {
  @Autowired
  private AsyncExceptionDemo asyncDemo;

  @Test
  public void contextLoads() throws InterruptedException, ExecutionException {
    asyncDemo.asyncInvokeSimplest();
    asyncDemo.asyncInvokeWithException("test");
    Future<String> future = asyncDemo.asyncInvokeReturnFuture(100);
    System.out.println(future.get());
  }
}

运行测试用例

MyAsyncConfigurer 捕获AsyncExceptionDemo 对象在调用asyncInvokeWithException的异常

2017-04-02 16:01:45.591 INFO 11152 --- [   MyAsync-1] c.h.s.a.exception.AsyncExceptionDemo   : asyncSimplest
2017-04-02 16:01:45.605 INFO 11152 --- [   MyAsync-1] c.h.s.a.exception.AsyncExceptionDemo   : asyncInvokeWithParameter, parementer=test
2017-04-02 16:01:45.608 INFO 11152 --- [   MyAsync-1] c.h.s.async.exception.MyAsyncConfigurer : Exception message - test
2017-04-02 16:01:45.608 INFO 11152 --- [   MyAsync-1] c.h.s.async.exception.MyAsyncConfigurer : Method name - asyncInvokeWithException
2017-04-02 16:01:45.608 INFO 11152 --- [   MyAsync-1] c.h.s.async.exception.MyAsyncConfigurer : Parameter value - test
2017-04-02 16:01:45.608 INFO 11152 --- [   MyAsync-1] c.h.s.a.exception.AsyncExceptionDemo   : asyncInvokeReturnFuture, parementer=100
error-IllegalArgumentException
2017-04-02 16:01:46.656 INFO 11152 --- [    Thread-2] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@47af7f3d: startup date [Sun Apr 02 16:01:44 CST 2017]; root of context hierarchy

5. 源码地址

代码的GITHUB地址

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。

# spring异步线程池  # spring  # async  # 线程池  # Spring中@Async用法详解及简单实例  # 关于Spring注解@Async引发其他注解失效的解决  # JAVA 中Spring的@Async用法总结  # Spring中@Async注解执行异步任务的方法  # Spring @Async 的使用与实现的示例代码  # Spring处理@Async导致的循环依赖失败问题的方案详解  # Java Spring的@Async的使用及注意事项示例总结  # 自定义  # 自己的  # 返回值  # 最简单  # 值为  # 可以看出  # 有两种  # 抛出  # 其实质  # 是在  # 不需要  # 推荐使用  # 适用于  # 给大家  # 此类  # 还需要  # 只是一个  # 可能出现  # 创建一个  # 使用这个 

相关栏目： 【 网站优化151355 】 【 网络推广146373 】 【 网络技术251813 】 【 AI营销90571 】

相关推荐： 零基础网站服务器架设实战：轻量应用与域名解析配置指南  教学论文网站制作软件有哪些,写论文用什么软件 ？  Windows11怎样设置电源计划_Windows11电源计划调整攻略【指南】  在线ppt制作网站有哪些软件,如何把网页的内容做成ppt？  Laravel的路由模型绑定怎么用_Laravel Route Model Binding简化控制器逻辑  HTML5空格和nbsp有啥关系_nbsp的作用及使用场景【说明】  专业商城网站制作公司有哪些,pi商城官网是哪个？  Laravel怎么配置自定义表前缀_Laravel数据库迁移与Eloquent表名映射【步骤】  Laravel如何实现URL美化Slug功能_Laravel使用eloquent-sluggable生成别名【方法】  奇安信“盘古石”团队突破 iOS 26.1 提权  js实现获取鼠标当前的位置  如何用ChatGPT准备面试 模拟面试问答与职场话术练习教程  Laravel路由怎么定义_Laravel核心路由系统完全入门指南  北京企业网站设计制作公司,北京铁路集团官方网站？  如何在服务器上配置二级域名建站？  Laravel如何保护应用免受CSRF攻击？（原理和示例）  如何在阿里云虚拟机上搭建网站？步骤解析与避坑指南  BootStrap整体框架之基础布局组件  Laravel怎么实现搜索高亮功能_Laravel结合Scout与Algolia全文检索【实战】  Laravel Session怎么存储_Laravel Session驱动配置详解  百度浏览器网页无法复制文字怎么办 百度浏览器复制修复  html5如何实现懒加载图片_ intersectionobserver api用法【教程】  网站页面设计需要考虑到这些问题  如何自定义safari浏览器工具栏？个性化设置safari浏览器界面教程【技巧】  JavaScript如何实现错误处理_try...catch如何捕获异常？  微信小程序 闭包写法详细介绍  JS弹性运动实现方法分析  如何快速查询网址的建站时间与历史轨迹？  🚀拖拽式CMS建站能否实现高效与个性化并存？  html5audio标签播放结束怎么触发事件_onended回调方法【教程】  利用 Google AI 进行 YouTube 视频 SEO 描述优化  Windows10如何删除恢复分区_Win10 Diskpart命令强制删除分区  Laravel怎么配置S3云存储驱动_Laravel集成阿里云OSS或AWS S3存储桶【教程】  Linux系统命令中screen命令详解  悟空识字怎么关闭自动续费_悟空识字取消会员自动扣费步骤  Laravel如何生成和使用数据填充？（Seeder和Factory示例）  如何打造高效商业网站？建站目的决定转化率  Laravel事件监听器怎么写_Laravel Event和Listener使用教程  Laravel如何升级到最新版本？（升级指南和步骤）  Laravel如何升级到最新的版本_Laravel版本升级流程与兼容性处理  如何在HTML表单中获取用户输入并用JavaScript动态控制复利计算循环  PHP的CURL方法curl_setopt()函数案例介绍(抓取网页,POST数据)  香港代理服务器配置指南：高匿IP选择、跨境加速与SEO优化技巧  JS碰撞运动实现方法详解  Laravel安装步骤详细教程_Laravel环境搭建指南  详解Android——蓝牙技术 带你实现终端间数据传输  高防服务器租用首荐平台，企业级优惠套餐快速部署  米侠浏览器网页背景异常怎么办 米侠显示修复  百度输入法ai组件怎么删除 百度输入法ai组件移除工具  悟空浏览器如何设置小说背景色_悟空浏览器背景色设置【方法】