Writing a JVM shutdown hook

Following is the class which exits on some condition. So before exit, if we need to carry out some task, register a shutdown hook(TestShutdownHook.java) with JVM

public class Test {
 
 public static void main(String args[]){
  
  Test test = new Test();
  TestShutdownHook testshutdownHook = new TestShutdownHook(test);
  Runtime.getRuntime().addShutdownHook(testshutdownHook);
  test.startTest();

 }

 private void startTest() {
  
  int counter = 0;
  while(true){
   if(counter == 100){
    System.exit(0);
   }
   System.out.println("Running..");
   counter++;
  }
 }

 public void beforeShutdownDothis() {
  System.out.println("Doing somethig before shutdown");
 }
}

package com.my;

public class TestShutdownHook extends Thread {
 
 private Test test;

 public TestShutdownHook(Test test){
  this.test = test;
 }
 
 public void run(){
  test.beforeShutdownDothis();
 }
}