Java???????????

???????????? ???????[ 2013/4/3 10:24:08 ] ????????

????3?????????????????????й????????ж??????????finalize()??????????????????????????????????????????????????????ò????????????????????????????????????????????

???????????????????????￡?

????2??Java??????4??????

????1???????????????????????????????????????????eg??Person person = new Person(“sunny”); ?????????????????????????????????????????????????????

????2????????????SoftReference??????eg : SoftReference<Person> p = new SoftReference<Person>(new Person(“Rain”));????????????????????????????????????????????????ж?????null????ж??????????????????

????3????????????WeakReference??????eg : WeakReference<Person> p = new WeakReference<Person>(new Person(“Rain”));??????????????????????????????????

????4???????????????????????????????????????????????????PhantomReference??????????ReferenceQueue?????????????eg??
package test;

import java.lang.ref.PhantomReference;
import java.lang.ref.ReferenceQueue;


public class Test{

     public static void main(String[] args) {
         //???????????
         Person person = new Person("Sunny");
         //??????????????
         ReferenceQueue<Person> rq = new ReferenceQueue<Person>();
         //????????????????????????????person????
         PhantomReference<Person> pr = new PhantomReference<Person>(person?? rq);
         //?ж?person?????????????????
         person = null;
         //??????????????????????
         //???????????????????÷?????????????????????null
         System.out.println(pr.get());
         //???????????
         System.gc();
         System.runFinalization();
         //?????????????е??????????????????????????????
         //???????????????????????????pr???б??????true
         System.out.println(rq.poll() == pr);
     }
}