MD5

import java.security.MessageDigest;

/**
* Md5加密公用类
*
* @author lei jin
*/
public class MD5{

private final static String enCoding = "utf-8";

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

public 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 + n;
}
int d1 = n / 16;
int d2 = n % 16;
return hexDigits[d1] + hexDigits[d2];
}

/**
* 对输入的源字符串进行Md5加密，返回加密后的32位字符串
*
* @param origin
*            加密源字符串
* @return
*/
public static String encrypt(String origin) {
String resultString = null;

try {
resultString = origin;
MessageDigest md = MessageDigest.getInstance("MD5");
resultString = byteArrayToHexString(md.digest(resultString
.getBytes(enCoding)));
} catch (Exception ex) {
throw new RuntimeException(ex);
}
return resultString;
}

public static void main(String[] args) {
String encryptPwd = MD5.encrypt("test");
System.out.println(encryptPwd);
}
}