目录

前言

Maven依赖

代码

总结

---

前言

工作中的场景中是否存在类似这样的场景，需要提交的线程在某个触发条件下执行。本文主要就是使用guava中的monitor来优雅的实现带监视器的线程。

Maven依赖

        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>31.0.1-jre</version>
        </dependency>

代码

不废话上代码。

package com.huyi.csdn.tools;

import cn.hutool.core.thread.ThreadUtil;
import com.google.common.util.concurrent.Monitor;
import org.springframework.scheduling.concurrent.CustomizableThreadFactory;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.function.Function;

/**
 * @Program: csdn @ClassName: MonitorRunner @Author: huyi @Date: 2021-10-30 15:22 @Description:
 * 监视器Runner @Version: V1.0
 */
public class MonitorRunner<T> implements Runnable {
  private T param;
  private Function<T, Boolean> condition;
  private Runnable runnable;
  private Monitor monitor;

  /**
   * 构造函数
   *
   * @param param 判断参数
   * @param condition 判定函数
   * @param runnable 执行内容
   */
  public MonitorRunner(T param, Function<T, Boolean> condition, Runnable runnable) {
    this.param = param;
    this.condition = condition;
    this.runnable = runnable;
    monitor = new Monitor();
  }

  @Override
  public void run() {
    System.out.println("线程开始");
    Monitor.Guard guard =
        new Monitor.Guard(monitor) {
          @Override
          public boolean isSatisfied() {
            return condition.apply(param);
          }
        };

    while (true) {
      if (monitor.enterIf(guard)) {
        try {
          runnable.run();
        } finally {
          monitor.leave();
          break;
        }
      } else {
        continue;
      }
    }
  }

  public T getParam() {
    return param;
  }

  public MonitorRunner<T> setParam(T param) {
    this.param = param;
    return this;
  }

  public static void main(String[] args) {
    ExecutorService executorService =
        Executors.newFixedThreadPool(10, new CustomizableThreadFactory("MONITOR-"));
    MonitorRunner<Integer> monitorRunner =
        new MonitorRunner<>(
            0,
            x -> x > 10,
            () -> {
              // todo 线程需要执行的内容
              System.out.println("今天天气真好");
            });
    executorService.submit(monitorRunner);
    while (monitorRunner.getParam() <= 10) {
      monitorRunner.setParam(monitorRunner.getParam() + 1);
      ThreadUtil.sleep(1000L);
      System.out.println("当前Param的值:" + monitorRunner.getParam());
    }
    ThreadUtil.sleep(5000L);
    executorService.shutdown();
  }
}

代码说明

主要在构造对象的时候需要传递泛型的校验对象，以及断言和需要执行的Runable。

执行结果

总结

没啥好总结的，看场景使用吧。

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