Java基础——MD5处理、加密、解密代码

MD5处理：

package com.test;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class MD5 {
    public static String Encrypt(String str){
        try {
            MessageDigest md=MessageDigest.getInstance("MD5");
            byte[] s=md.digest(str.getBytes());
            String ss="";
            String result="";
            for(int i=0;i                 ss=Integer.toHexString(s[i] & 0xff);
                if(ss.length()==1){
                    result+="0"+ss;
                }else{
                    result+=ss;
                }
            }
            return result;
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return null;
    }
}

加密：

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;  
 
    }

测试：

String userName = "dongdongma";
        System.out.println("原始字符串："+userName);
        System.out.println("MD5后："+MD5.Encrypt(userName));
        System.out.println("加密后："+MD5.convertMD5(userName));
        System.out.println("解密后："+MD5.convertMD5(MD5.convertMD5(userName)));

 

OR

public static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname))
                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
            else
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
        } catch (Exception exception) {
        }
        return resultString;
    }

private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
            resultSb.append(byteToHexString(b[i]));

        return resultSb.toString();
    }

private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n += 256;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d",
            "e", "f" };

public static void main(String[] args){
        String result = MD5Util.MD5Encode("叮当猫", "UTF-8");
        System.out.println("result="+result);  
    }

result=70784eb997ad27a63f815b4fc524f851