Utils#

public class Utils#

Utility functions.

Fields#

EMAIL_PATTERN#

public static final Pattern EMAIL_PATTERN#

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#

public static String InputStream2String(InputStream is)#

Helper function calling InputStream2String for charset UTF-8.

InputStream2String#

public static String InputStream2String(InputStream is, String charset)#

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

Parameters:

  • is – The input stream

Returns:

The detected string or an empty string if the stream has become empty.

String2InputStream#

public static InputStream String2InputStream(String s)#

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

URLDecodeWithUTF8#

public static String URLDecodeWithUTF8(String string)#

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.

Parameters:

  • string

Returns:

decoded string.

See also: {@linkUtils.URLEncodeWithUTF8(String)}

URLEncodeWithUTF8#

public static String URLEncodeWithUTF8(String string)#

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.

Parameters:

  • string

Returns:

encoded string.

See also: {@linkUtils.URLDecodeWithUTF8(String)}

checkPasswordStrength#

public static void checkPasswordStrength(String password)#

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.

Parameters:

  • password – The password to be checked.

document2String#

public static String document2String(Document document)#

Converts a Document into a String. For debugging purposes.

Parameters:

  • document

Returns:

String representation of the document.

element2String#

public static String element2String(Element e)#

Converts an Element into a String. For debugging purposes.

Parameters:

  • e – The Element

Returns:

String representation of the element.

getReadableByteSize#

public static String getReadableByteSize(Long fssize)#

Converts file sizes to human readably sizes.

For example, getReadableByteSize(2048) == “2KiB”.

getSecureFilename#

public static String getSecureFilename(int byteSize)#

Generate a secure filename (base32 letters and numbers).

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

Parameters:

  • byteSize – How many bytes of random bits shall be generated.

Returns:

The filename as a String.

getUID#

public static String getUID()#

Generate a UID (Hexadecimal).

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

Returns:

The UID as a String.

hash#

public static String hash(MessageDigest md, String string, String salt, int it)#
Parameters:

  • alg – The hashing algorithm implementation.

  • string – The string to be hashed.

  • salt – Cryptographic salt.

  • it – Number of iterations. Zero and negative integers don’t make any sense. Therefore, if it<=1 the hashing is done once.

Returns:

Hashed string, or null if string is null

isRFC822Compliant#

public static boolean isRFC822Compliant(String email)#

Check if email is RFC822 compliant.

Parameters:

  • email

Returns:

true when the email given by the String email is RFC822 compliant.

log#

public static double log(int base, Long x)#

Intended to compute the maximum exponent for the required conversion.

sha512#

public static String sha512(String string, String salt, int it)#

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.

Parameters:

  • string – The string to be hashed.

  • salt – Cryptographic salt.

  • it – Number of iterations. Zero and negative integers don’t make any sense. Therefore, if it<=1 the hashing is done once.

Returns:

Hashed string, or null if string is null