java md5方法

public static String md5(String string) {
    byte[] hash;
    try {
        hash = MessageDigest.getInstance("MD5").digest(string.getBytes("UTF-8"));
    } catch (NoSuchAlgorithmException e) {
        throw new RuntimeException("Huh, MD5 should be supported?", e);
    } catch (UnsupportedEncodingException e) {
        throw new RuntimeException("Huh, UTF-8 should be supported?", e);
    }
 
    StringBuilder hex = new StringBuilder(hash.length * 2);
    for (byte b : hash) {
        if ((b & 0xFF) < 0x10) hex.append("0");
        hex.append(Integer.toHexString(b & 0xFF));
    }
    return hex.toString();
}