惡漢模式：Ehan.java

package com.cn.danli;

/**
 * 餓漢式單例模式
 */
public class Ehan {

    private static Ehan eh = new Ehan();
    
    private Ehan(){
        
    }
    
    public static Ehan getEhan(){
        return eh;
    }
    
}

2、懶漢模式：Lanhan.java

package com.cn.danli;

/**
 * 懶漢式單例模式
 */
public class
 
 Lanhan {
    //私有化當前對象
    private static Lanhan lh = null;
    
    //私有化構造函數
    private Lanhan(){
    
    }
    
    //公有的對象提供對象方法
    public static synchronized Lanhan getLanhan(){
        if(lh == null){
            lh = new Lanhan();
        }
        
        return lh;
    }
    
}

3、Test.java

package
 
 com.cn.danli;

import java.util.Stack;

public class Test {

    public static void main(String[] args) {
        String str = "123456789";
        char[] strs = str.toCharArray();
        
        for(int i=0;i<strs.length-1;i++){
            for(int j=0;j<strs.length-1-i;j++){
                
 
if(strs[j]<strs[j+1]){
                    char c = strs[j];
                    strs[j] = strs[j+1];
                    strs[j+1] = c;
                }
            }
        }
        
        System.out.println(strs);
        
    }
    
}

Spring 單例模式