项目中线程池的应用

1、首先我们需要在配置类中将线程池作为单例bean配置

@Configuration
public class ThreadPoolExecutorConfig {
    @Bean
    ExecutorService executorService(){
        return new ThreadPoolExecutor(
                2,
                3,
                0,
                TimeUnit.MICROSECONDS,
                new ArrayBlockingQueue<>(3),
                (r)->new Thread(r,"name"+System.currentTimeMillis()),
                new ThreadPoolExecutor.AbortPolicy()
        );
    }

}

2、 然后再对应的service中注入我们的ExecutorService

package com.example.threaddemo.demos;

import com.example.threaddemo.mapper.TestMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.concurrent.*;
@Component
public class Test {


    @Autowired
    private ExecutorService executorService;
    @Autowired
    private TestMapper testMapper;


}

3、在方法中调用我们的线程池对象并且执行我们传入的任务

package com.example.threaddemo.demos;

import com.example.threaddemo.mapper.TestMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.concurrent.*;
@Component
public class Test {


    @Autowired
    private ExecutorService executorService;
    @Autowired
    private TestMapper testMapper;

    public void test() {
        Future<?> submit = executorService.submit(testMapper::Test1);
        System.out.println(submit.getClass());
    }


}


//下方是mapper文件，假设在操作数据库
package com.example.threaddemo.mapper;

import org.springframework.stereotype.Component;
@Component
public class TestMapper {
    public void Test1(){
        System.out.println("Test");
    }
}

4、简述执行流程

1. 首先程序会构建线程池
2. 当我们使用方法引用将上方指定的mapper中的方法传入线程池的submit方法中时，实际是传入到线程池中的Runnable的run方法，程序会根据我们的run方法进行执行
3. 使用submit方法可以获取到返回值对象Future实例，通过Future实例可以调用get方法获取到我们所期待的返回值
4. 但是此时这个submit是阻塞式的，他会阻塞调用它的线程直到get方法成功获取到返回值，此时可以考虑使用 execute 方法