线程池（三）----ThreadPoolTaskExecutor

一、介绍：对ThreadPoolExecutor的进一步封装，实际应用中一般使用ThreadPoolTaskExecutor而不是ThreadPoolExecutor。对于ThreadPoolTaskExecutor，项目中只初始化一次bean。

二、应用举例：假设有三个耗时任务，一个返回结果，一个不返回结果，一个不返回结果且批量执行

1、ThreadPoolTaskExecutorConfig：

将ThreadPoolTaskExecutor做为一个bean，通过spring的注入，保证只会初始化一次。

package exceldemo.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

@Configuration
public class ThreadPoolTaskExecutorConfig {
    private static int CORE_POOL_SIZE = 5;
    private static int MAX_POOL_SIZE = 1000;
    @Bean(name="threadPoolTaskExecutor")
    public ThreadPoolTaskExecutor serviceJobTaskExecutor(){
        ThreadPoolTaskExecutor poolTaskExecutor = new ThreadPoolTaskExecutor();
        //线程池维护线程的最少数量
        poolTaskExecutor.setCorePoolSize(CORE_POOL_SIZE);
        //线程池维护线程的最大数量
        poolTaskExecutor.setMaxPoolSize(MAX_POOL_SIZE);
        //线程池所使用的缓冲队列
        poolTaskExecutor.setQueueCapacity(200);
        //线程池维护线程所允许的空闲时间
        poolTaskExecutor.setKeepAliveSeconds(30000);
        poolTaskExecutor.setWaitForTasksToCompleteOnShutdown(true);
        System.out.println(poolTaskExecutor);
        return poolTaskExecutor;
    }
}

2、服务：

package exceldemo.service.impl;

import exceldemo.dto.User;
import exceldemo.service.UserService;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;

@Service("userService")
public class UserServiceImpl implements UserService {
    @Override
    public List getByIds(List ids) {

        List users = new ArrayList<>();
        for(Integer id : ids){
            User user = new User();
            user.setAge(id);
            user.setUserName("用户"+id);
            //耗时操作
            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            users.add(user);
        }
        return users;
    }

    @Override
    public void addUserAction() {

        //耗时操作
        try {
            Thread.sleep(20);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("行为记录");
    }
}

 3、需要提交的task：

package exceldemo.task;

import exceldemo.dto.User;
import exceldemo.service.UserService;

import java.util.List;
import java.util.concurrent.Callable;

public class UserTask  implements Callable> {

    private List userIds;

    private UserService userService;

    public UserTask(List queryIds, UserService userService) {
        this.userService = userService;
        this.userIds = queryIds;
        //System.out.println("ids  "+queryIds.size());
    }


    @Override
    public List call() throws Exception {
        //System.out.println("*******************");
        List users = userService.getByIds(userIds);
        return users;
    }
}

异步任务：

package exceldemo.task;

import java.util.List;

public class DemoTask implements Runnable {

    private List ids ;

    public  DemoTask(List ids){
        this.ids = ids;
    }

    @Override
    public void run() {
        try {
            Thread.sleep(500);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        //System.out.println("run "+ids.size());
    }
}

4、controller：

package exceldemo.rest;

import exceldemo.dto.User;
import exceldemo.service.UserService;
import exceldemo.task.UserTask;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;

@RestController
@RequestMapping("/user1")
public class UserController {

    @Autowired
    private UserService userService;

    @Autowired
    private ThreadPoolTaskExecutor threadPoolTaskExecutor;

    @RequestMapping("/getAllSc")
    public List getAllSc(){
       
        List ids = new ArrayList<>();
        for(int i = 0;i<=500;i++){
            ids.add(i);
        }
        //1、异步通知
        threadPoolTaskExecutor.execute(new Runnable() {
            @Override
            public void run() {
                userService.addUserAction();
            }
        });

        //2、批量异步通知
        List childIds = new ArrayList<>();
        for (int i = 0; i < ids.size(); i += 100) {
            int startIndex = i;
            int endIndex = startIndex + 100 > ids.size() ? ids.size() : startIndex + 100;
            DemoTask task = new DemoTask(ids.subList(startIndex, endIndex));
           threadPoolTaskExecutor.execute(task);
        }

        //3、异步获取所有用户
        long startTime = new Date().getTime();
        List users = new ArrayList<>();
        List futures = new ArrayList<>();

        for (int i = 0; i < ids.size(); i += 100) {
            int startIndex = i;
            int endIndex = startIndex + 100 > ids.size() ? ids.size() : startIndex + 100;
            UserTask task = new UserTask(ids.subList(startIndex, endIndex),userService);
            Future> future = threadPoolTaskExecutor.submit(task);
            futures.add(future);
        }
        //取数据
        try{
            for(Future future : futures){
                users.addAll((List) future.get());
            }
        }catch (Exception e){

        }

        long endTime = new Date().getTime();
        System.out.println("耗时"+(endTime-startTime));
        return users;
    }
}

控制台打印：

行为记录
耗时1046