@EnableAsync@Async多线程异步执行

小鱼儿 2023-01-17 12:54 169阅读 0赞

我们在使用多线程的时候，往往需要创建Thread类，或者实现Runnable接口，如果要使用到线程池，我们还需要来创建Executors，在使用spring中，已经给我们做了很好的支持。只要要@EnableAsync就可以使用多线程。使用@Async就可以定义一个线程任务。通过spring给我们提供的ThreadPoolTaskExecutor就可以使用线程池。

### 定义配置类,如果不配置可直接将@EnableAsync注解加到启动类上面 ###

import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.scheduling.annotation.AsyncConfigurer;
    import org.springframework.scheduling.annotation.EnableAsync;
    import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
    import java.util.concurrent.Executor;
    
    @Configuration
    @EnableAsync
    public class ThreadPoolTaskConfig implements AsyncConfigurer {
        private static final int corePoolSize = 5;       		// 核心线程数（默认线程数）
        private static final int maxPoolSize = 10;			    // 最大线程数
        private static final int keepAliveTime = 10;			// 允许线程空闲时间（单位：默认为秒）
        private static final int queueCapacity = 25;			// 缓冲队列数
        @Override
        public Executor getAsyncExecutor() {
            //线程池
            ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
            taskExecutor.setCorePoolSize(corePoolSize);
            taskExecutor.setMaxPoolSize(maxPoolSize);
            taskExecutor.setKeepAliveSeconds(keepAliveTime);
            taskExecutor.setQueueCapacity(queueCapacity);
            taskExecutor.initialize();
            return taskExecutor;
        }
    
        @Override
        public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
            return null;
        }
    }

### **service** ###

import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.scheduling.annotation.Async;
    import org.springframework.stereotype.Service;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    @Service
    public class testAsyncService {
        Logger log = LoggerFactory.getLogger(testAsyncService.class);
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    
        @Async
        public void service1() throws InterruptedException {
            log.info("--------start-service1:"+ df.format(new Date()) +"------------");
            Thread.sleep(5000); // 模拟耗时
            log.info("--------end-service1:"+ df.format(new Date()) +"------------");
        }
    
    
        @Async
        public void service2() throws InterruptedException {
            log.info("--------start-service2:"+ df.format(new Date()) +"------------");
            Thread.sleep(2000); // 模拟耗时
            log.info("--------end-service2:"+ df.format(new Date()) +"------------");
    
        }
    }

### controller ###

import com.example.demotest.service.testAsyncService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class controller {
        @Autowired
        testAsyncService service;
        @GetMapping("/get")
        public void test() throws InterruptedException {
            for(int i=0;i<3;i++) {
                service.service1();
                service.service2();
            }
        }
    }

**测试结果，可以看到并不是顺序执行，说明异步执行成功。**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xldHRlcnNz_size_16_color_FFFFFF_t_70][]

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