使用多线程实现异步任务

一、springboot中的异步任务 1、使用注解@Async创建一个可异步启动的方法

import lombok.SneakyThrows;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;


@Service
public class BeforeCall {


    @SneakyThrows
    @Async
    public void asyncBefore()  {
        Thread.sleep(3000);
        System.out.println("异步方法先调用但是后打印");
    }
}

2、创建一个方便观察的普通方法

import org.springframework.stereotype.Service;

@Service
public class AfterCall {


    public void afcall(){
        System.out.println("普通方法，后调用但是先打印");
    }
}

3、在一个方法中同时调用上面的方法

import com.cai.li.asynctask.service.AfterCall;
import com.cai.li.asynctask.service.BeforeCall;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@ResponseBody
@RequestMapping("/test")
public class DataController {

    @Autowired
    BeforeCall beforeCall;

    @Autowired
    AfterCall afterCall;

    @RequestMapping("/asynctask")
    public void test(){
        beforeCall.asyncBefore();
        afterCall.afcall();
    }


}

4、在springboot启动类上加上注解@EnableAsync

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.scheduling.annotation.EnableAsync;

@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableAsync
public class AsynctaskApplication {

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

}

5、访问查看结果

二、一个线程获取另一个线程中值 1、新建一个类First，类实现Runable接口，在重写的run()方法中获取另一线程中的First类的属性name的值

import lombok.SneakyThrows;

public class First implements Runnable{

    @SneakyThrows
    @Override
    public void run() {
        Thread.sleep(5000);
        Second first = new Second();
        System.out.println("先调用但是后打印");
        System.out.println("新线程"+Thread.currentThread().getName()+"获取的name:"+first.name);

    }
}

2、新建一个类Second，类中的方法Data()负责给属性name赋值

public class Second {

	//属性一定要加static变为静态属性，其他线程取值时才有数据，否则取到的就会是null
    static String name;

    public void Data(String data){
        this.name = data;
        System.out.println("后调用但是后打印");
        System.out.println("线程"+Thread.currentThread().getName()+"中获取到的name:"+name);
    }
}

3、新建一个测试的类

public class AsyncTetst {

    public static void main(String[] args) {
        First first = new First();
        Second second = new Second();
        new Thread(first).start();
        second.Data("Lii");
    }

}

4、运行后的结果