bad finalize method

TestFinalizeMethod.java

package test.jvm.gc;

public class TestFinalizeMethod {
  
  public static T t;

  public static void main(String[] args) throws InterruptedException {
    run();
    System.out.println(t==null?1:2);
    System.gc();
    Thread.sleep(3000);
    System.out.println(t==null?1:2);
    t = null;
    System.out.println(t==null?1:2);
    System.gc();
    Thread.sleep(3000);
    System.out.println(t==null?1:2);
  }
  
  public static void run() {
    T t = new T();
  }

  public static class T {
    int i = 1;
    @Override
    protected void finalize() throws Throwable {
      TestFinalizeMethod.t = this;                      // save itself
      System.err.println(new RuntimeException("haha")); // only call it once    
      throw new RuntimeException("haha");               //ignore exception
    }
  }
  
}