计算字节数组的SHA-1

关于什么：

import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;import java.util.Formatter;public static String SHAsum(byte[] convertme) throws NoSuchAlgorithmException{    MessageDigest md = MessageDigest.getInstance("SHA-1");     return byteArray2Hex(md.digest(convertme));}private static String byteArray2Hex(final byte[] hash) {    Formatter formatter = new Formatter();    for (byte b : hash) {        formatter.format("%02x", b);    }    return formatter.toString();}