package org.fireoct.utils;

/**
 * Created by Pan on 2016/10/6.
 */
public class Singleton {
    /**
     * @return Singleton(唯一)
     * 單例模式
     */
    public static Singleton getSingleton() {
        return singleton;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this
 
.msg = msg;
    }

    private static Singleton singleton = new Singleton();
    //用於演示，可根據自己需要去掉
    private String msg = "default message : singleton.";

    private Singleton() {
    }

}

package org.fireoct.utils;

/**
 * Created by Pan on 2016/10/6.
 * 測試單例模式-Singleton
 */
public class SingletonTest
 
 {
    public static void main(String[] args) {
        Singleton sin01 = Singleton.getSingleton();
        System.out.println("sin01:"+sin01.getMsg());
        Singleton sin02 = Singleton.getSingleton();
        System.out.println("sin02:"+sin02.getMsg());
        sin02.setMsg("sin02 changed the msg");
        System.out.println("sin02:"
 
 + sin02.getMsg());
        //列印sin01物件的msg屬性值，如果和sin02物件修改了msg屬性值之後的一樣，則表示sin01和sin02為同一個物件，即單例模式生效了。
        System.out.println("sin01:"+sin01.getMsg());
        //或者採用equals方法比較，這樣更直觀。
        System.out.println(sin01.equals(sin02));
    }
}