多线程获取返回值

一、多线程获取返回值

1、实现Callable接口（实现方式有两种）
(1）使用线程池

logger.info("001: " + new Date());
// 线程1在处理
ThreadTestService threadTestService = new ThreadTestService();
threadTestService.setNumber(10);
// 通过线程池实现线程
ExecutorService executorService = Executors.newFixedThreadPool(1);
Future< ThreadModel> future = executorService.submit(threadTestService);
// 线程2（主线程）在处理
int num1 = threadService.getNumber();
// 线程1处理完则获取数据，线程1处理中则阻塞
ThreadModel threadModel = future.get();

logger.info("003: " + new Date());

logger.info(String.valueOf(num1 + threadModel.getNum()));

ThreadTestService.java

public class ThreadTestService implements Callable< ThreadModel> {
    private int number;
    private Logger logger = LoggerFactory.getLogger(ThreadTestService.class);
    @Override
    public ThreadModel call() {
        ThreadModel model = new ThreadModel();
        try {
            logger.info("threadTest start " + new Date());
            Thread.sleep(10000);
            logger.info("threadTest end " + new Date());
        } catch (InterruptedException e) {
            e.printStackTrace();
            logger.error("error", e);
        }
        model.setNum(number);
        return model;
    }
    public void setNumber(int number) {
        this.number = number;
    }
}

(2）使用FuntureTask

logger.info("001: " + new Date());
// 线程1在处理
ThreadTestService threadTestService = new ThreadTestService();
threadTestService.setNumber(10);
// 通过FutureTask实现线程
FutureTask< ThreadModel> futureTask = new FutureTask(threadTestService);
Thread thread = new Thread(futureTask);
thread.start();
// 线程2（主线程）在处理
int num1 = threadService.getNumber();
//线程1 获取数据（线程1处理完则获取数据，线程1处理中则阻塞）
ThreadModel threadModel = futureTask.get();

logger.info("003: " + new Date());

logger.info(String.valueOf(num1 + threadModel.getNum()));

2. 使用@Async注解
注：使用@Async注解，须在启动类加注解@EnableAsync

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
@EnableAsync
public class FinanceServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(FinanceServerApplication.class, args);
    }

}

logger.info("001: " + new Date());
// 线程1在处理
Future< ThreadModel> future =threadTestService.task(1);
// 线程2（主线程）在处理
int num1 = threadService.getNumber();
//线程1 获取数据（线程1处理完则获取数据，线程1处理中则阻塞）
ThreadModel threadModel = future.get();

logger.info("003: " + new Date());

logger.info(String.valueOf(num1 + threadModel.getNum()));

@Async注解的返回值为Future<>,需返回其实现类AsyncResult<>

@Service
public class ThreadTestService{
    private Logger logger = LoggerFactory.getLogger(ThreadTestService.class);
    @Async
    public Future<ThreadModel> task(int number) {
        ThreadModel model = new ThreadModel();
        try {
            logger.info("threadTest start " + new Date());
            Thread.sleep(10000);
            logger.info("threadTest end " + new Date());
        } catch (InterruptedException e) {
            e.printStackTrace();
            logger.error("error", e);
        }
        model.setNum(number);
        return new AsyncResult<>(model);
    }
}