java中进行加密和解密的方法

package com.jh.hiv.test.service.test;
import java.io.UnsupportedEncodingException;

import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.codec.binary.Base64;
import org.junit.Test;
public class test12 {
    static final String TARGET = "changeme";      
    
    /*  
     * 不可逆算法  MD5  
     */    
    @Test    
    public void Md5()    
    {    
        String str = DigestUtils.md5Hex(TARGET);    
        System.out.println("md5Hex:     "+str);    
    }    
    /*  
     * 不可逆算法  SHA1  
     */    
    @Test    
    public void Sha1()    
    {    
        String str = DigestUtils.shaHex(TARGET);    
        print("shaHex:     "+str);    
        str = DigestUtils.sha256Hex(TARGET);    
        print("sha256Hex:  "+str);    
        str = DigestUtils.sha384Hex(TARGET);    
        print("sha384Hex:  "+str);    
        str = DigestUtils.sha512Hex(TARGET);    
        print("sha512Hex:  "+str);    
    }    
        
       
     /*  
      * 可逆算法  BASE64  
      */  
         
    @Test    
    public void Base64() throws UnsupportedEncodingException    
    {    
        //加密    
        byte[] b = Base64.encodeBase64(TARGET.getBytes(), true);    
        String str = new String(b,"utf-8");    
        print("BASE64:     "+str);    
            
        //解密    
        byte[] b1 = Base64.decodeBase64(str);    
        print("解密之后内容为：  "+new String(b1));    
    }    
    @Test  
    public void testList16() {  
    String name = "440889199302162657";  
    char f = name.charAt(0);
    
    System.out.println(f);
    if (name.length() <= 1) {  
        System.out.println("*");  
    } else {  
//        System.out.println(name.replaceAll("([\\u4e00-\\u9fa5]{1})(.*)", "$1" + createAsterisk(name.length() - 1)+name.substring(name.length()-1)));  
        System.out.println(name.substring(0,2)+ createAsterisk(name.length() - 1)+name.substring(name.length()-1));
    //获取字符的位数name.substring(m,n)   m代表从第几位开始索引，n代表长度
    }  
    }
    private String createAsterisk(int length) {
        // TODO Auto-generated method stub
        StringBuffer stringBuffer = new StringBuffer();  
        for (int i = 0; i < length; i++) {  
            stringBuffer.append("*");  
        }  
        return stringBuffer.toString();
    }    
    
    
    public void print(Object obj)    
    {    
        System.out.println(obj);    
    }
    
}  

打印输出：结果如下

shaHex:     fa9beb99e4029ad5a6615399e7bbae21356086b3
sha256Hex:  057ba03d6c44104863dc7361fe4578965d1887360f90a0895882e58a6248fc86
sha384Hex:  7d49d02c105312b2b69de69141b27de1f4f4c202b4afb19d7ff7ab9849e9ce2da165a87eeec971bca66c8eb8a9243f5e
sha512Hex:  f1891cea80fc05e433c943254c6bdabc159577a02a7395dfebbfbc4f7661d4af56f2d372131a45936de40160007368a56ef216a30cb202c66d3145fd24380906
md5Hex:     4cb9c8a8048fd02294477fcb1a41191a
BASE64:     Y2hhbmdlbWU=

解密之后内容为：  changeme
4
44*****************7