技術標籤：JavaSpring bootSpringjava

package com.lgq.demo;

import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.test.context.ActiveProfiles;

import java.util.
 
concurrent.CountDownLatch;
import java.util.concurrent.ThreadPoolExecutor;

/**
 * 多執行緒測試
 *
 * @Author: guanqin_li
 * @Date: 2021-02-18 10:39
 */
@SpringBootTest
@ActiveProfiles("dev")
public class ThreadTest {
    @Test
    public void test() throws InterruptedException {
        ThreadPoolTaskExecutor executor =
 
 new ThreadPoolTaskExecutor();
        executor.setThreadNamePrefix("thread-pool-");
        executor.setCorePoolSize(5);
        executor.setMaxPoolSize(10);
        executor.setQueueCapacity(100);
        executor.setKeepAliveSeconds(300);
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.
 
CallerRunsPolicy());
        executor.setWaitForTasksToCompleteOnShutdown(true);
        executor.initialize();
        // 任務總數
        final int total = 20;
        CountDownLatch countDownLatch = new CountDownLatch(total);
        System.out.println("=========start=======");
        for (int i = 0; i < total; i++) {
            executor.execute(() -> {
                try {
                    //TODO 業務處理
                    System.out.println(Thread.currentThread().getName() + "|" + countDownLatch.getCount());
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    // 很關鍵, 無論上面程式是否異常必須執行countDown,否則await無法釋放
                    countDownLatch.countDown();
                }
            });
        }
        // 所有執行緒countDown()都執行之後才會釋放當前執行緒,程式才能繼續往後執行
        countDownLatch.await();
        //關閉執行緒池
        executor.shutdown();
        System.out.println("=========finished=======");
    }
}

執行結果：

2021-02-18 10:50:07.000  INFO 115072 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService
=========start=======
thread-pool-1|20
thread-pool-1|19
thread-pool-1|18
thread-pool-1|17
thread-pool-1|16
thread-pool-1|15
thread-pool-1|14
thread-pool-1|13
thread-pool-1|12
thread-pool-1|11
thread-pool-1|10
thread-pool-1|9
thread-pool-1|8
thread-pool-1|7
thread-pool-1|6
thread-pool-1|5
thread-pool-2|4
thread-pool-3|4
thread-pool-4|2
thread-pool-5|1
2021-02-18 10:50:07.006  INFO 115072 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService
=========finished=======