package com.gc;

public class TestGc {

  public static void main(String[] args) {

    Man man = new Man("a");

    Person a = new Person();

    a.setMan(man);

    a.setMan(null);

    man = null;

    System.out.println("before gc");

    System.gc();

    System.out.println("right after gc");

    try {

      Thread.sleep(1000);

    } catch (InterruptedException e) {

      // TODO Auto-generated catch block

      e.printStackTrace();

    }

    System.out.println("after gc");

    System.out.println(a.getMan() == null? null :a.getMan().getName());

  }

}

package com.gc;

public class Person {

  private Man man;

  public Man getMan() {

    return man;

  }

  public void setMan(Man man) {

    this.man = man;

  }

}

package com.gc;

public class Man {

  private String name;

  public Man(String name) {

  }

  public String getName() {

    return name;

  }

  public void setName(String name) {

    this.name = name;

  }

  @Override

  protected void finalize() throws Throwable {

    System.out.println("execute method finalize()"+ name);

    super.finalize();

  }

}