Android获取apk签名指纹的md5值(防止重新被打包)的实现方法

/** * MD5加密 * @param byteStr 需要加密的内容 * @return 返回 byteStr的md5值 */public static String encryptionMD5(byte[] byteStr) {  MessageDigest messageDigest = null;  StringBuffer md5StrBuff = new StringBuffer();  try {    messageDigest = MessageDigest.getInstance("MD5");    messageDigest.reset();    messageDigest.update(byteStr);    byte[] byteArray = messageDigest.digest();    for (int i = 0; i < byteArray.length; i++) {      if (Integer.toHexString(0xFF & byteArray[i]).length() == 1) {        md5StrBuff.append("0").append(Integer.toHexString(0xFF & byteArray[i]));      } else {        md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));      }    }  } catch (NoSuchAlgorithmException e) {    e.printStackTrace();  }  return md5StrBuff.toString();}

/** * 获取app签名md5值 */public String getSignMd5Str() {  try {    PackageInfo packageInfo = mActivity.getPackageManager().getPackageInfo(mActivity.getPackageName(), PackageManager.GET_SIGNATURES);    Signature[] signs = packageInfo.signatures;    Signature sign = signs[0];    String signStr = encryptionMD5(sign.toByteArray());    return signStr;  } catch (PackageManager.NameNotFoundException e) {    e.printStackTrace();  }  return "";}