.. java:import:: java.io ByteArrayInputStream

.. java:import:: java.io InputStream

.. java:import:: java.io UnsupportedEncodingException

.. java:import:: java.security MessageDigest

.. java:import:: java.security NoSuchAlgorithmException

.. java:import:: java.security SecureRandom

.. java:import:: java.text DecimalFormat

.. java:import:: java.util Scanner

.. java:import:: java.util.regex Pattern

.. java:import:: org.apache.commons.codec.binary Base32

.. java:import:: org.caosdb.server CaosDBServer

.. java:import:: org.caosdb.server ServerProperties

.. java:import:: org.caosdb.server.entity Message

.. java:import:: org.jdom2 Document

.. java:import:: org.jdom2 Element

.. java:import:: org.jdom2.output Format

.. java:import:: org.jdom2.output XMLOutputter

Utils
=====

.. java:package:: org.caosdb.server.utils
   :noindex:

.. java:type:: public class Utils

   Utility functions.

Fields
------
EMAIL_PATTERN
^^^^^^^^^^^^^

.. java:field:: public static final Pattern EMAIL_PATTERN
   :outertype: Utils

   Regular expression pattern that checks a mail for RFC822 compliance.

   Taken from: http://www.ex-parrot.com/~pdw/Mail-RFC822-Address.html

   This belongs to the perl module "Mail::RFC822::Address". It is copyright 2001-2002 by Paul Warren. The license can be found here: http://www.ex-parrot.com/~pdw/Mail-RFC822-Address/Mail-RFC822-Address.html#copyright%20and%20license

Methods
-------
InputStream2String
^^^^^^^^^^^^^^^^^^

.. java:method:: public static String InputStream2String(InputStream is)
   :outertype: Utils

   Helper function calling InputStream2String for charset UTF-8.

InputStream2String
^^^^^^^^^^^^^^^^^^

.. java:method:: public static String InputStream2String(InputStream is, String charset)
   :outertype: Utils

   Return a string from the input stream is up to the next LF (line feed, \\A) character.

   :param is: The input stream
   :return: The detected string or an empty string if the stream has become empty.

String2InputStream
^^^^^^^^^^^^^^^^^^

.. java:method:: public static InputStream String2InputStream(String s) throws UnsupportedEncodingException
   :outertype: Utils

   Helper function to convert a String into an UTF-8 encoded ByteArrayInputStream.

URLDecodeWithUTF8
^^^^^^^^^^^^^^^^^

.. java:method:: public static String URLDecodeWithUTF8(String string)
   :outertype: Utils

   Exception-free decoding of URI-encoded Strings with UTF-8. Any UnsupportedEncodingException will terminate the server since this would by no means be an acceptable run-time environment if UTF-8 is not available.

   :param string:
   :return: decoded string.

   **See also:** :java:ref:`{@linkUtils.URLEncodeWithUTF8(String)}`

URLEncodeWithUTF8
^^^^^^^^^^^^^^^^^

.. java:method:: public static String URLEncodeWithUTF8(String string)
   :outertype: Utils

   Exception-free URI-encoding of strings using UTF-8. Any UnsupportedEncodingException will terminate the server since this would by no means be an acceptable run-time environment if UTF-8 is not available.

   :param string:
   :return: encoded string.

   **See also:** :java:ref:`{@linkUtils.URLDecodeWithUTF8(String)}`

checkPasswordStrength
^^^^^^^^^^^^^^^^^^^^^

.. java:method:: public static void checkPasswordStrength(String password) throws Message
   :outertype: Utils

   Determines the strength of a password. Currently this just throws an error when the String `password` does not at least contain - An uppercase char - A lowercase char - A number - A punctuation char and if the length is not at least 8 characters.

   correcthorsebatterystaple is also rejected.

   :param password: The password to be checked.

document2String
^^^^^^^^^^^^^^^

.. java:method:: public static String document2String(Document document)
   :outertype: Utils

   Converts a Document into a String. For debugging purposes.

   :param document:
   :return: String representation of the document.

element2String
^^^^^^^^^^^^^^

.. java:method:: public static String element2String(Element e)
   :outertype: Utils

   Converts an Element into a String. For debugging purposes.

   :param e: The Element
   :return: String representation of the element.

getReadableByteSize
^^^^^^^^^^^^^^^^^^^

.. java:method:: public static String getReadableByteSize(Long fssize)
   :outertype: Utils

   Converts file sizes to human readably sizes.

   For example, getReadableByteSize(2048) == "2KiB".

getSecureFilename
^^^^^^^^^^^^^^^^^

.. java:method:: public static String getSecureFilename(int byteSize)
   :outertype: Utils

   Generate a secure filename (base32 letters and numbers).

   Very similar to getUID, but uses cryptographic random number instead, also nicely formats the resulting string.

   :param byteSize: How many bytes of random bits shall be generated.
   :return: The filename as a String.

getUID
^^^^^^

.. java:method:: public static String getUID()
   :outertype: Utils

   Generate a UID (Hexadecimal).

   Currently this generates two random long numbers and concatenates their hex representations. This function is thread-safe.

   :return: The UID as a String.

hash
^^^^

.. java:method:: public static String hash(MessageDigest md, String string, String salt, int it)
   :outertype: Utils

   :param alg: The hashing algorithm implementation.
   :param string: The string to be hashed.
   :param salt: Cryptographic salt.
   :param it: Number of iterations. Zero and negative integers don't make any sense. Therefore, if it<=1 the hashing is done once.
   :return: Hashed string, or null if string is null

isRFC822Compliant
^^^^^^^^^^^^^^^^^

.. java:method:: public static boolean isRFC822Compliant(String email)
   :outertype: Utils

   Check if email is RFC822 compliant.

   :param email:
   :return: true when the email given by the String email is RFC822 compliant.

log
^^^

.. java:method:: public static double log(int base, Long x)
   :outertype: Utils

   Intended to compute the maximum exponent for the required conversion.

sha512
^^^^^^

.. java:method:: public static String sha512(String string, String salt, int it)
   :outertype: Utils

   This function returns the SHA512 hash of a given string, salt and number of iterations. This function terminates the application completely with an error code when this hashing algorithm is not available.

   :param string: The string to be hashed.
   :param salt: Cryptographic salt.
   :param it: Number of iterations. Zero and negative integers don't make any sense. Therefore, if it<=1 the hashing is done once.
   :return: Hashed string, or null if string is null