加密-MD5Util

package com.tea.web.admin;

import java.security.MessageDigest;

public class MD5Util {
    public static void main(String args[]) {
        String s = new String("anwu55");
        System.out.println("原始：" + s);
        System.out.println("MD5后：" + string2MD5(s));
        System.out.println("加密的：" + convertMD5(s));
        System.out.println("解密的：" + convertMD5(convertMD5(s)));        
    }
    
    /***
     * MD5加码 生成32位md5码
     */
    public static String string2MD5(String inStr){
        try {
            byte[] btInput = inStr.getBytes("utf-8");
            MessageDigest mdInst = MessageDigest.getInstance("MD5");
            mdInst.update(btInput);
            byte[] md = mdInst.digest();
            StringBuffer sb = new StringBuffer();
            for (int i = 0; i < md.length; i++) {
                int val = ((int) md[i]) & 0xff;
                if (val < 16){
                    sb.append("0");
                }
                sb.append(Integer.toHexString(val));
            }
            return sb.toString();
        } catch (Exception e) {
            return null;
        }
    }

    /**
     * 加密解密算法 执行一次加密，两次解密
     */ 
    public static String convertMD5(String inStr){
        char[] a = inStr.toCharArray();
        for (int i = 0; i < a.length; i++){
            a[i] = (char) (a[i] ^ 't');
        }
        String s = new String(a);
        return s;
    } 
}