不安全的哈希算法 缺少必要加密步骤 - 修复建议

在hash加密的过程，执行所有必需的步骤，确保不会削弱所生成hash值的强度。

MessageDigest messageDigest = MessageDigest.getInstance("SHA-512");   
messageDigest.update(inputText.getBytes());     
byte byteBuffer[] = messageDigest.digest();    
StringBuilder strHexString = new StringBuilder();  
for (int i = 0; i < byteBuffer.length; i++) {  
    String hex = Integer.toHexString(0xff & byteBuffer[i]);    
    if (hex.length() == 1) {  
        strHexString.append('0');    
    }  
    strHexString.append(hex);    
}    
strResult = strHexString.toString();