springboot中多線程的使用

多線程：多個線程並發的執行

1、創建配置文件

@Configuration
@EnableAsync
public class ThreadConfig {
    @Bean("doSomethingExecutor")
    public Executor doSomethingExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        // 核心線程數：線程池創建時候初始化的線程數
        executor.setCorePoolSize(10);
        // 最大線程數：線程池最大的線程數，只有在緩沖隊列滿了之后才會申請超過核心線程數的線程
        executor.setMaxPoolSize(20);
        // 緩沖隊列：用來緩沖執行任務的隊列
        executor.setQueueCapacity(500);
        // 允許線程的空閑時間60秒：當超過了核心線程之外的線程在空閑時間到達之后會被銷毀
        executor.setKeepAliveSeconds(60);
        // 線程池名的前綴：設置好了之后可以方便我們定位處理任務所在的線程池
        executor.setThreadNamePrefix("do-something-");
        // 緩沖隊列滿了之后的拒絕策略：由調用線程處理（一般是主線程）
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.DiscardPolicy());
        executor.initialize();
        return executor;
    }
}

2、創建線程任務

• ThreadTaskService

public interface ThreadTestService {
    // 無返回值的線程任務
    void threadTask(int i);
    // 有返回值的線程任務
    CompletableFuture<String> threadTaskWithReturn01();
    CompletableFuture<String> threadTaskWithReturn02();
    CompletableFuture<String> threadTaskWithReturn03();
    CompletableFuture<String> threadTaskWithReturn04();
}

• ThreadTaskServiceImp

import com.baizhou.service.ThreadTestService;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.stereotype.Service;

import java.util.concurrent.CompletableFuture;

@Service
@EnableAsync //開啟線程
public class ThreadTestServiceImp implements ThreadTestService {
    @Override
    @Async(value = "doSomethingExecutor") //聲明線程任務
    public void threadTask(int i) {
        System.out.println("線程:"+Thread.currentThread().getName()+":"+i);
    }
    @Override
    @Async(value = "doSomethingExecutor") //聲明線程任務
    public CompletableFuture<String> threadTaskWithReturn01() {
        return CompletableFuture.completedFuture(Thread.currentThread().getName()+":threadTaskWithReturn01()執行");
    }
    @Override
    @Async(value = "doSomethingExecutor") //聲明線程任務
    public CompletableFuture<String> threadTaskWithReturn02() {
        return CompletableFuture.completedFuture(Thread.currentThread().getName()+":threadTaskWithReturn02()執行");

    }
    @Override
    @Async(value = "doSomethingExecutor") //聲明線程任務
    public CompletableFuture<String> threadTaskWithReturn03() {
        return CompletableFuture.completedFuture(Thread.currentThread().getName()+":threadTaskWithReturn03()執行");

    }
    @Override
    @Async(value = "doSomethingExecutor") //聲明線程任務
    public CompletableFuture<String> threadTaskWithReturn04() {
        return CompletableFuture.completedFuture(Thread.currentThread().getName()+":threadTaskWithReturn04()執行");
    }
}

3、測試

@SpringBootTest
class SpringbootMybatisPlusApplicationTests02 {
    @Autowired
    private ThreadTestService  threadTestService;
    @Test
    void ThreadTest(){
        long start=System.currentTimeMillis();
        for(int i=0;i<10;i++){
            try{
                Thread.sleep(1000);
                threadTestService.threadTask(i);//執行線程任務
            }catch (Exception e){
                throw new RuntimeException(e);
            }
        }
    }
    @Test
    void ThreadTest02() throws ExecutionException, InterruptedException {
        // 執行線程任務
        CompletableFuture<String> doSomeThing01=threadTestService.threadTaskWithReturn01();
        CompletableFuture<String> doSomeThing02=threadTestService.threadTaskWithReturn02();
        CompletableFuture<String> doSomeThing03=threadTestService.threadTaskWithReturn03();
        CompletableFuture<String> doSomeThing04=threadTestService.threadTaskWithReturn04();
        // 等待所有的線程都執行完畢
        CompletableFuture.allOf(doSomeThing01,doSomeThing02,doSomeThing03,doSomeThing04);
        //獲取每個任務的返回結果
        System.out.println(doSomeThing01.get());
        System.out.println(doSomeThing02.get());
        System.out.println(doSomeThing03.get());
        System.out.println(doSomeThing04.get());
    }
}

• 結果

// 不帶返回值
線程:do-something-1:0
線程:do-something-2:1
線程:do-something-3:2
線程:do-something-4:3
線程:do-something-5:4
線程:do-something-6:5
線程:do-something-7:6
線程:do-something-8:7
線程:do-something-9:8
線程:do-something-10:9
//帶返回值
do-something-1:threadTaskWithReturn01()執行
do-something-2:threadTaskWithReturn02()執行
do-something-3:threadTaskWithReturn03()執行
do-something-4:threadTaskWithReturn04()執行