singleton.java

所学课程的编码。java的基础例子。可以练习java通过这些例子。。

/* David Java File
 * Created on 2006-9-26
 *
 * TODO To change the template for this generated file go to
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 */
package chap04;

/**
 * 
 */
class Unique{
   private static final Unique INSTANCE =new Unique();
   int a;
    private Unique(){
    }
    public static Unique getInstance(){
        return INSTANCE;
    }
}
public class Singleton {

    public static void main(String[] args) {
        Unique u1= Unique.getInstance();
        u1.a=5;
        Unique u2= Unique.getInstance();
        u2.a=3;
        System.out.println(u1==u2); 
        System.out.println(u1.equals(u2)); 
        System.out.println(u1.a); 
     }
}