@Async注解的坑

问题描述

一个方法调用另一个方法(该方法使用@Async注解)在同一个类文件中，该注解会失效！

问题复现

TestAsyncController 类

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Async;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/test")
public class TestAsyncController {

    private static final Logger logger = LoggerFactory.getLogger(TestAsyncController.class);

    @PostMapping("/test")
    public void test() {
        logger.info("测试异步开始...");
        try {
            test1();
        } catch (Exception e) {
            e.printStackTrace();
        }
        logger.info("测试异步结束...");
    }

    @Async
    public void test1(){
        for(int i=0;i<5;i++){
            logger.info("i={}",i);
        }
    }
}

问题测试结果

可以看出是全部使用的主线程

问题解决

将@Async注解的方法放在一个新的类文件中即可

TestAsyncService类

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;

@Service
public class TestAsyncService {

    private static final Logger logger = LoggerFactory.getLogger(TestAsyncService.class);

    @Async
    public void test1(){
        for(int i=0;i<5;i++){
            logger.info("i={}",i);
        }
    }
}

TestAsyncController类

import com.example.demo.service.TestAsyncService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/test")
public class TestAsyncController {

    private static final Logger logger = LoggerFactory.getLogger(TestAsyncController.class);

    @Autowired
    private TestAsyncService asyncService;

    @PostMapping("/test")
    public void test() {
        logger.info("测试异步开始...");
        try {
            asyncService.test1();
        } catch (Exception e) {
            e.printStackTrace();
        }
        logger.info("测试异步结束...");
    }
}

测试结果

可以看出@Async注解开启新的子线程

问题原因需要各位大佬们帮忙解答!