public class MD5 {
/***
* MD5加碼 生成32位md5碼
*/
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();
}
/**
* 加密解密算法 執行一次加密，兩次解密
*/
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;
}
// 測試主函數
public static void main(String args[]) {
String s = new String("123456789");
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)));
}
}