public class MD5Test {

/***

* MD5加密 生成32位md5码

*

* @return 返回32位md5码

*/

public static String md5Encode(String inStr) throws Exception {

MessageDigest md5 = null;

try {

md5 = MessageDigest.getInstance("MD5");

} catch (Exception e) {

System.out.println(e.toString());

e.printStackTrace();

return "";

}

byte[] byteArray = inStr.getBytes("UTF-8");

byte[] md5Bytes = md5.digest(byteArray);

StringBuffer hexValue = new StringBuffer();

for (int i = 0; i < md5Bytes.length; i++) {

int val = ((int) md5Bytes[i]) & 0xff;

if (val < 16) {

hexValue.append("0");

}

hexValue.append(Integer.toHexString(val));

}

return hexValue.toString();

}

public static String string2MD5(String inStr) {

MessageDigest md5 = null;

try {

md5 = MessageDigest.getInstance("MD5");

} catch (Exception e) {

System.out.println(e.toString());

e.printStackTrace();

return "";

}

char[] charArray = inStr.toCharArray();

byte[] byteArray = new byte[charArray.length];

for (int i = 0; i < charArray.length; i++)

byteArray[i] = (byte) charArray[i];

byte[] md5Bytes = md5.digest(byteArray);

StringBuffer hexValue = new StringBuffer();

for (int i = 0; i < md5Bytes.length; i++) {

int val = ((int) md5Bytes[i]) & 0xff;

if (val < 16)

hexValue.append("0");

hexValue.append(Integer.toHexString(val));

}

return hexValue.toString();

}

/**

* 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;

}

/**

* 解密算法 (执行一次加密)进行两次解密

* @param str

* @return

*/

public static String md5Decode(String str) {

return convertMD5(convertMD5(str));

}

// 测试主函数

public static void main(String args[]) {

String s = new String("13917114404");

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)));

}

}