guava SimpleTimeLImiter进行方法超时调用控制

最新推荐文章于 2025-09-16 01:07:00 发布

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本文介绍了如何使用Guava的SimpleTimeLimiter进行方法调用的超时控制，包括基于类级别和方法级别的实现方式。通过示例代码展示了如何设置超时时间，当超时时如何捕获并处理错误。SimpleTimeLimiter实际上是通过包装Executor的Future来实现超时功能。

1、基于类级别的调用

（1）编写接口类UserInfoService.java

public interface UserInfoService {
    String getUserName() throws InterruptedException;
}

（2）编写对应的实现类UserInfoServiceImpl.java

public class UserInfoServiceImpl implements UserInfoService {

    @Override
    public String getUserName() throws InterruptedException {
        System.out.println("123");
        Thread.sleep(500);
        System.out.println("456");
        return "tim";
    }
}

(3) 测试代码

 public static void main(String[] args) {
        TimeLimiter timeLimiter = new SimpleTimeLimiter();
        UserInfoService userInfoService = new UserInfoServiceImpl();
        UserInfoService userInfoService1 = timeLimiter.newProxy(userInfoService, UserInfoService.class, 20, TimeUnit.MILLISECONDS);
        try {
            String userName = userInfoService1.getUserName();
            System.out.println("userName:" + userName);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

（4）综合上述可以写成更通用的

/**
 * @author chenjintian
 * @email chenjintian@meituan.com
 * @date 2018/9/29
 * Description:
 */
public class UserInfoServiceImpl implements UserInfoService {
    
    private static final TimeLimiter TIME_LIMITER = new SimpleTimeLimiter();
    // 设置为可配置
    private static final long TIME_OUT_DURATION = 200;
    
    private static UserInfoService userInfoServiceProxy;
    
    static {
        UserInfoService userInfoService = new UserInfoServiceImpl();
        userInfoServiceProxy = TIME_LIMITER.newProxy(userInfoService, UserInfoService.class, TIME_OUT_DURATION, TimeUnit.MILLISECONDS);
    }

    @Override
    public String getUserName(String info) throws InterruptedException {
        System.out.println("123");
        Thread.sleep(500);
        System.out.println("456");
        return info;
    }

    @Override
    public String getUserNameWithTimeout(String info) throws InterruptedException {
        return userInfoServiceProxy.getUserName(info);
    }

    @Override
    public String getSex(String txt) {
        return "";
    }

    @Override
    public String getSexWithTimeout(String txt) {
        return userInfoServiceProxy.getSex(txt);
    }


    public static void main(String[] args) throws InterruptedException {
        UserInfoService userInfoService = new UserInfoServiceImpl();
        String result = userInfoService.getUserNameWithTimeout("tim");
        System.out.println("result is:" + result);
    }

}

2、基于方法级别的调用

public class SimpleTimeLimiterDemo {

    public static void main(String[] args) {

        SimpleTimeLimiter simpleTimeLimiter = new SimpleTimeLimiter();
        final AtomicBoolean isInterrupted = new AtomicBoolean();

        Callable<String> task = new Callable<String>() {
            @Override
            public String call() throws Exception {
                isInterrupted.set(true);
                Thread.sleep(200);
                isInterrupted.set(false);
                return "success";
            }
        };

        try {
            String result = simpleTimeLimiter.callWithTimeout(task, 20, TimeUnit.MILLISECONDS, true);
            System.out.println(result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

分析：

上述代码实现调用方法超时后会报错。

查看源码本质上，Google的SimpleTimeLimiter是对Executor的future的包装。