要在定时任务里面监听一个进程java

在Java中，在定时任务（如`ScheduledExecutorService`、`Timer`或Spring框架中的`@Scheduled`注解）里监控一个进程通常涉及到操作系统级别的操作，因为这需要获取到进程的状态信息。这里有一个简单的例子，使用`ManagementFactory`和`OperatingSystemMXBean`来检查进程是否存在：

import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;

public class ProcessMonitorTask implements Runnable {
    private String processName;
    private ScheduledExecutorService executor;

    public ProcessMonitorTask(String processName, ScheduledExecutorService executor) {
        this.processName = processName;
        this.executor = executor;
    }

    @Override
    public void run() {
        OperatingSystemMXBean osBean = ManagementFactory.getOperatingSystemMXBean();
        if (osBean.isProcessRunning(processName)) {
            System.out.println("Process " + processName + " is running.");
        } else {
            System.err.println("Process " + processName + " has stopped.");
        }
        
        // 可能需要定期执行这个检查，比如每分钟一次
        executor.schedule(this, 60, TimeUnit.SECONDS);
    }

    // 如果你需要在定时任务结束后停止监听，可以在适当的地方添加取消任务的逻辑
}

// 使用示例
ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
scheduler.scheduleAtFixedRate(new ProcessMonitorTask("your-process-name", scheduler), 0, 1, TimeUnit.MINUTES);