java 生成MD5

public class MD5Util {
private final static String[] hexDigits = { "0", "1", "2", "3", "4", "5",
"6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
/**
* 转换字节数组为16进制字串
*
* @param b
*            字节数组
* @return 16进制字串
*/
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];
}
public static String MD5Encode(String origin) {
String resultString = null;
try {
resultString = new String(origin);
MessageDigest md = MessageDigest.getInstance("MD5");
resultString = byteArrayToHexString(md.digest(resultString
.getBytes()));
} catch (Exception ex) {
}
return resultString;
}
/**
* Test MD5
* @param args
*/
public static void main(String[] args) {
System.err.println(MD5Encode("0"));
System.err.println(MD5Encode("0"));
}