一 點睛

使用註解@EnableAsync開啟非同步，會自動掃描

定義@Component @Async作為元件被容器掃描執行

非同步任務執行使用場景

1 傳送簡訊

2 傳送郵件

3 App訊息推送

4 節省運維凌晨釋出任務時間提供效率

二 啟動類

package com.imooc;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;

import tk.mybatis.spring.annotation.MapperScan;

@SpringBootApplication
//掃描 mybatis mapper 包路徑
@MapperScan(basePackages = "com.imooc.mapper")
//掃描 所有需要的包, 包含一些自用的工具類包 所在的路徑
@ComponentScan(basePackages= {"com.imooc", "org.n3r.idworker"})
//開啟定時任務
@EnableScheduling
//開啟非同步呼叫方法
@EnableAsync
public class ImoocApplication {

    public static void main(String[] args) {
        SpringApplication.run(ImoocApplication.class, args);
    }
}
 

三 控制器

package com.imooc.tasks;

import java.util.concurrent.Future;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("tasks")
public class DoTask {
    
    @Autowired
    private AsyncTask asyncTask;
    
    @RequestMapping("test1")
    public String test1() throws Exception {
        
        long start = System.currentTimeMillis();
        
        Future<Boolean> a = asyncTask.doTask11();
        Future<Boolean> b = asyncTask.doTask22();
        Future<Boolean> c = asyncTask.doTask33();
        
        while (!a.isDone() || !b.isDone() || !c.isDone()) {
            if (a.isDone() && b.isDone() && c.isDone()) {
                break;
            }
        }
        
        long end = System.currentTimeMillis();
        
        String times = "任務全部完成，總耗時：" + (end - start) + "毫秒";
        System.out.println(times);
        
        return times;
    }
}
 

四 非同步任務定義

package com.imooc.tasks;

import java.util.concurrent.Future;

import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.AsyncResult;
import org.springframework.stereotype.Component;

@Component
public class AsyncTask {
    
    @Async
    public Future<Boolean> doTask11() throws Exception {
        long start = System.currentTimeMillis();
        Thread.sleep(1000);
        long end = System.currentTimeMillis();
        System.out.println("任務1耗時:" + (end - start) + "毫秒");
        return new AsyncResult<>(true);
    }
    
    @Async
    public Future<Boolean> doTask22() throws Exception {
        long start = System.currentTimeMillis();
        Thread.sleep(700);
        long end = System.currentTimeMillis();
        System.out.println("任務2耗時:" + (end - start) + "毫秒");
        return new AsyncResult<>(true);
    }
    
    @Async
    public Future<Boolean> doTask33() throws Exception {
        long start = System.currentTimeMillis();
        Thread.sleep(600);
        long end = System.currentTimeMillis();
        System.out.println("任務3耗時:" + (end - start) + "毫秒");
        return new AsyncResult<>(true);
    }
}
 

五 測試