1.使用配置文件配置线程的参数

配置文件

thread-pool:
  core-size: 100
  max-size: 100
  keep-alive-seconds: 60
  queue-capacity: 1

配置类

@Component
@ConfigurationProperties("thread-pool")
@Data
public class ThreadPoolConfig {
    private int coreSize;

    private int maxSize;

    private int keepAliveSeconds;

    private int queueCapacity;
}

2.配置线程池并使用

方式一：线程池结合CompletableFuture来实现

配置线程池类

@Configuration
public class ThreadPoolTask1 {

    @Autowired
    private ThreadPoolConfig threadPoolConfig;

    @Bean("task1")
    public ThreadPoolTaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(threadPoolConfig.getCoreSize()); // 核心线程数
        executor.setMaxPoolSize(threadPoolConfig.getMaxSize()); // 最大线程数
        executor.setKeepAliveSeconds(threadPoolConfig.getKeepAliveSeconds()); // 非核心线程活跃时间
        executor.setQueueCapacity(threadPoolConfig.getQueueCapacity()); // 队列容量
        executor.setThreadNamePrefix("test-"); // 设置线程的前缀名
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy()); // 设置拒绝策略
        executor.setWaitForTasksToCompleteOnShutdown(false); // 是否在任务执行完后关闭线程池
        executor.initialize();
        return executor;
    }
}

CompletableFuture使用线程池进行调用

package com.example.demo;

import com.example.demo.config.ThreadPoolTask1;
import com.sun.java.browser.plugin2.DOM;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.*;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.stream.Collectors;

@RestController
public class Demo {

    @Autowired
    private DemoServiceImpl demoService;

    @Autowired
    @Qualifier("task1")
    private ThreadPoolTaskExecutor threadPoolTask1;

    @GetMapping("thread1")
    public Map<String, String> thread1() {
        long start = System.currentTimeMillis();
        List<CompletableFuture<String>> futures = new ArrayList<>();
        Map<String, String> map = new HashMap<>();
        // 使用CompletableFuture的 supplyAsync来处理结果相当于submit， runAsync无返回相当于execute
        for (int i = 0; i < 100; i++) {
            int b = i;
            CompletableFuture<String> future = CompletableFuture.supplyAsync(() ->
                            demoService.executorTask1(b)
                    , threadPoolTask1);
            futures.add(future);
        }

        // 获取结果集
        CompletableFuture.allOf(futures.toArray(new CompletableFuture[futures.size()]))
                .whenComplete((v, th) ->
                    futures.stream()
                            .forEach(item -> {
                                String result = null;
                                try {
                                    result = item.get();
                                } catch (InterruptedException e) {
                                    e.printStackTrace();
                                } catch (ExecutionException e) {
                                    e.printStackTrace();
                                }
                                map.put(result.split("-")[1], result.split("-")[0]);
                            })
                ).join();
        long end = System.currentTimeMillis();
        map.put("当前时间",(end- start) + "");
        return map;
    }
}

任务类

public String executorTask1(int i) {
        System.out.println("当前线程-" + Thread.currentThread().getName());
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        if (i == 6) {
            throw new RuntimeException("cs");
        } else {
            return "aaa-" + i;
        }
    }

方式二：使用@EnableAsync和@Async方式实现

在启动类上加@EnableAsync注解

// 加上@EnableAsync注解，也可以在自己的配置类上加
@EnableAsync // 开启对异步任务的支持
@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
                SpringApplication.run(DemoApplication.class, args);
        
    }
}

编写线程池配置

// 也可以在此处加上@EnableAsync注解，入口类上不加
@Configuration
public class ThradPoolTask{

    @Autowired
    private ThreadPoolConfig threadPoolConfig;

    @Bean
    public Executor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(threadPoolConfig.getCoreSize()); // 核心线程数
        executor.setMaxPoolSize(threadPoolConfig.getMaxSize()); // 最大线程数
        executor.setKeepAliveSeconds(threadPoolConfig.getKeepAliveSeconds()); // 非核心线程活跃时间
        executor.setQueueCapacity(threadPoolConfig.getQueueCapacity()); // 队列容量
        executor.setThreadNamePrefix("test-"); // 设置线程的前缀名
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy()); // 设置拒绝策略
        executor.setWaitForTasksToCompleteOnShutdown(false); // 是否在任务执行完后关闭线程池
        executor.initialize();
        return executor;
    }
}

使用

@RestController
public class Demo {

    @Autowired
    private DemoServiceImpl demoService;

    @GetMapping("thread")
    public Map<String, String> thread() {
        long start = System.currentTimeMillis();
        Map<String, String> map = new HashMap<>();
        List<Future<String>> futures = new ArrayList<>();

        for (int i = 0; i < 100; i++) {
            Future<String> future = demoService.executorTask(i);
            futures.add(future);
        }
        int b = 1;
        futures.forEach(item -> {
            try {
                String result = item.get();
                map.put(result.split("-")[1], result.split("-")[0]);
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                e.printStackTrace();
            }
        });
        long end = System.currentTimeMillis();
        map.put("当前时间",(end- start) + "");
        return map;
    }
}

任务类

// 必须指明使用的是哪个线程池，taskExecutor不带的话用springboot默认注册的线程池
    // Future作为返回值，携带返回结果
    @Async("taskExecutor")
    public Future<String> executorTask(int i) {
        System.out.println("当前线程-" + Thread.currentThread().getName());
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        if (i == 6) {
            throw new RuntimeException("cs");
        } else {
        	// AsyncResult返回携带的结果
            return new AsyncResult<String>("aaa-" + i);
        }
    }

方式三：重写springboot默认的线程池配置

在启动类上加@EnableAsync注解

// 加上@EnableAsync注解，也可以在自己的配置类上加
@EnableAsync
@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
                SpringApplication.run(DemoApplication.class, args);
        
    }
}
@Configuration
public class ThreadPoolTask2 implements AsyncConfigurer {

    @Autowired
    private ThreadPoolConfig threadPoolConfig;

    /**
     * 修改默认线程池的配置
     *
     * @return
     */
    @Override
    public Executor getAsyncExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(threadPoolConfig.getCoreSize()); // 核心线程数
        executor.setMaxPoolSize(threadPoolConfig.getMaxSize()); // 最大线程数
        executor.setKeepAliveSeconds(threadPoolConfig.getKeepAliveSeconds()); // 非核心线程活跃时间
        executor.setQueueCapacity(threadPoolConfig.getQueueCapacity()); // 队列容量
        executor.setThreadNamePrefix("test2-"); // 设置线程的前缀名
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy()); // 设置拒绝策略
        executor.setWaitForTasksToCompleteOnShutdown(false); // 是否在任务执行完后关闭线程池
        executor.initialize();
        return executor;
    }

    /**
     * 修改默认的异常处理
     * 注意：如果带有返回值Future,异常会被捕获，不会去执行该方法
     *
     * @return
     */
    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        return (ex, method, params) -> {
            System.out.println("任务执行的异常" + ex);
            System.out.println("执行的任务方法" + method.getName());
            for (Object param : params) {
                System.out.println("执执行任务的参数" + param);
            }
        };
    }
}

使用

@RestController
public class Demo {

    @Autowired
    private DemoServiceImpl demoService;

	// 不带返回值的任务
    @GetMapping("thread2")
    public Map<String, String> thread2() {
        long start = System.currentTimeMillis();
        Map<String, String> map = new HashMap<>();
        List<Future<String>> futures = new ArrayList<>();

        for (int i = 0; i < 100; i++) {
            demoService.executorTask2(i);
        }
        return null;
    }

	// 带有返回值的任务
    @GetMapping("thread3")
    public Map<String, String> thread3() {
        long start = System.currentTimeMillis();
        Map<String, String> map = new HashMap<>();
        List<Future<String>> futures = new ArrayList<>();

        for (int i = 0; i < 100; i++) {
            Future<String> future = demoService.executorTask3(i);
            futures.add(future);
        }
        int b = 1;
        futures.forEach(item -> {
            String result = null;
            try {
                result = item.get();
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                e.printStackTrace();
            }
            map.put(result.split("-")[1], result.split("-")[0]);
        });
        long end = System.currentTimeMillis();
        map.put("当前时间",(end- start) + "");
        return map;
    }
}

任务类

// @Async不需要指定，使用默认即可
	// 出现异常会走AsyncUncaughtExceptionHandler方法
    @Async
    public void executorTask2(int i) {
        System.out.println("当前线程-" + Thread.currentThread().getName());
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        int a = 1/0;
    }

	// 即使出现异常也不会走AsyncUncaughtExceptionHandler方法
    @Async
    public Future<String> executorTask3(int i) {
        System.out.println("当前线程-" + Thread.currentThread().getName());
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        if (i == 6) {
            throw new RuntimeException("cs");
        } else {
            return new AsyncResult<String>("aaa-" + i);
        }
    }

关于三种在执行过程中的异常

方式一：导致请求失败：最好在任务中进行处理

spring boot 线程池配置 springboot线程池参数_java

方式二：请求成功了，关于6的那条数据并没有返回给前端

spring boot 线程池配置 springboot线程池参数_System_02

方式三：请求成功了，关于6的那条数据并没有返回给前端