如何在 Java 中监控线程的状态？
原文:https://www . geesforgeks . org/how-monitor-a-threads-status-in-Java/
Java 语言通过使用监视器支持线程同步。监视器与特定的数据项相关联，并充当该数据的锁。当一个线程持有某个数据项的监视器时，其他线程被锁定，不能检查或修改数据。为了监控一个线程的状态，Java 有预定义的 方法，该方法由线程类扩展。java.lang.reflect.Method 类的 getName()方法 用于获取实体的名称，作为 String，该实体可以是类、接口、数组、枚举、方法等。类对象的。java . lang . reflect的 getName() 方法。方法类有助于获取方法的名称，如字符串。要获取一个类的所有方法的名称，请获取该类对象的所有方法。然后在这些方法对象上调用 getName()。
语法:
public String getName()
返回值:返回方法名，字符串形式。
示例:
Java 语言(一种计算机语言，尤用于创建网站)
// Java Program to Monitor a Thread's Status
// Class 1
// Helper class
class MyThread extends Thread {
// Initially initializing states using boolean methods
boolean waiting = true;
boolean ready = false;
// Constructor of this class
MyThread() {}
// Methods of this class are as follows:
// Method 1
synchronized void startWait()
{
try {
while (!ready)
wait();
}
catch (InterruptedException exc) {
System.out.println("wait() interrupted");
}
}
// Method 2
synchronized void notice()
{
ready = true;
notify();
}
// Method 3
// To run threads when called using start()
public void run()
{
// Getting the name of current thread
// using currentThread() and getName() methods
String thrdName = Thread.currentThread().getName();
// Print the corresponding thread
System.out.println(thrdName + " starting.");
// While the thread is in waiting state
while (waiting)
System.out.println("waiting:" + waiting);
// Display message
System.out.println("waiting...");
// calling the Method1
startWait();
// Try block to check for exceptions
try {
// Making thread to pause execution for a
// certain time of 1 second using sleep() method
Thread.sleep(1000);
}
// Catch block to handle the exceptions
catch (Exception exc) {
// Display if interrupted
System.out.println(thrdName + " interrupted.");
}
// Else display the thread is terminated.
System.out.println(thrdName + " terminating.");
}
}
// Class 2
// Main class
public class GFG {
// Method 1
// To get the thread status
static void showThreadStatus(Thread thrd)
{
System.out.println(thrd.getName()
+ " Alive:=" + thrd.isAlive()
+ " State:=" + thrd.getState());
}
// Method 2
// Main driver method
public static void main(String args[]) throws Exception
{
// Creating an object of our thread class
// in the main() method
MyThread thrd = new MyThread();
// Setting the name for the threads
// using setname() method
thrd.setName("MyThread #1");
// getting the status of current thread
showThreadStatus(thrd);
// Starting the thread which automatically invokes
// the run() method for the thread
thrd.start();
// Similarly repeating the same
Thread.sleep(50);
showThreadStatus(thrd);
// hee notice we change the flag value
// thai is no more in waiting state now
thrd.waiting = false;
Thread.sleep(50);
showThreadStatus(thrd);
thrd.notice();
Thread.sleep(50);
showThreadStatus(thrd);
// Till thread is alive
while (thrd.isAlive())
// Print the statement
System.out.println("alive");
// Callin the method
showThreadStatus(thrd);
}
}
输出:
[https://media.geeksforgeeks.org/wp-content/uploads/20210423141355/thread_status.mp4](https://media.geeksforgeeks.org/wp-content/uploads/20210423141355/thread_status.mp4)版权属于：月萌API www.moonapi.com，转载请注明出处
