org.tentackle.util
Class StringHelper

java.lang.Object
  org.tentackle.util.StringHelper

public class StringHelper
extends Object

Some handy methods for strings.

Author:

harald

Field Summary

static char	creditLetter short letter for "credit" (haben)
static DateFormat	dateFormat localized DateFormat for a date
static String	datePattern localized format string for a date
static char	debitLetter short letter for "debit" (soll)
static String	emptyString the empty string
static String	floatDoublePattern default float/double format string
static String	integerPattern default integer format string
static String	lineSeparatorString the newline string
static char[]	MD5SALT Salt for md5sum(char[]). The default is null, i.e.
static String	moneyPattern default money format string
static DateFormat	shortDateFormat localized DateFormat for a short date
static String	shortDatePattern localized format string for a short date
static DateFormat	shortTimeFormat localized DateFormat for a short time
static String	shortTimePattern localized format string for a short time
static DateFormat	shortTimestampFormat localized DateFormat for a short timestamp
static String	shortTimestampPattern localized format string for a short timestamp
static StringConverter	stringNormalizer The default normalizer used within the application.
static DateFormat	timeFormat localized DateFormat for a time
static String	timePattern localized format string for a time
static DateFormat	timestampFormat localized DateFormat for a timestamp
static String	timestampPattern localized format string for a timestamp

Constructor Summary

StringHelper()

Method Summary

static String	debitCreditToString(BMoney money, boolean debit) Translates a money value to a string with a suffix indicating whether debit or credit.
static String	firstLine(String str) Gets the first line from a multi-line string.
static String	getClassBaseName(Class<?> clazz) Gets the basename of a class.
static String	getClassBaseName(String str) Gets the basename of a classname(-like) string.
static boolean	isAllDigits(String str) checks if a string contains only digits, i.e.
static boolean	isAllDigits(String str, boolean whitespaceAllowed) Checks if a string contains only digits or whitespaces, i.e.
static boolean	isAllWhitespace(String str) Checks if string contains only whitespaces.
static void	loadFormats() Loads the localized formats.
static String	md5sum(char[] input) Builds an MD5-sum from an array of chars with a default salt given by MD5SALT.
static String	md5sum(char[] salt, char[] input) Builds an MD5-sum from an array of chars as used in password-fields. Note that this method converts the characters to bytes via toBytes(char[]) before applying the md5 hash.
static String	normalize(String str) Normalizes a string (phonetically) for use as AppDbObject.normText using stringNormalizer.
static String	normalize(String str, StringConverter normalizer) Normalizes a string (phonetically) for use as AppDbObject.normText.
static String	objectArrayToString(Object[] objArray, String separator) Creates a string from an object array.
static byte[]	toBytes(char c) Converts a single (unicode) char to a byte-array.
static byte[]	toBytes(char[] chars) Converts a char-array to a byte-array.
static char[]	toCharArray(String str) Transforms a string to a char-array.
static String	toDoubleQuotes(String str) Takes a string, surrounds it with double-quotes and escapes all double-quotes already in the string according to Unix rules.
static String	toDTA(String str) Filters illegal chars for DTA-Files (German "DATENAUSTAUSCH" banking format).
static String	toFixedLength(String str, int length) Takes a string and returns one with a given length, cutting or filling up with spaces, whatever appropriate.
static String	toFixedLength(String str, int length, char filler) Takes a string and returns one with a given length, cutting or filling up with fillchars, whatever appropriate.
static String	toFixedLengthLeftFill(String str, int length) Takes a string and returns one with a given length, cutting or filling up with spaces from the left, whatever appropriate.
static String	toFixedLengthLeftFill(String str, int length, char filler) Takes a string and returns one with a given length, cutting or filling up with fillchars from the left, whatever appropriate.
static String	toHexString(byte[] binaryData) Creates a human-readable hex-String out of a byte-array (e.g.
static String	toHTML(String text) Converts a multiline string to an HTML-string that can be displayed in a label.
static String	toString(String str) Maps null to the empty string.
static String	toVarName(String str) Filters illegal chars for Java variable names.
static String	toWindowsDoubleQuotes(String str) Takes a string, surrounds it with double-quotes and escapes all double-quotes already in the string according to Windows-rules.
static String	trim(String s) Trims a string.
static String	trim(String s, int max) Trims a string.
static String	unDiacrit(String str) Converts special unicode characters (so-called diacrits) to standard ascii.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

integerPattern

public static final String integerPattern

default integer format string

See Also:

Constant Field Values

floatDoublePattern

public static final String floatDoublePattern

default float/double format string

See Also:

Constant Field Values

moneyPattern

public static final String moneyPattern

default money format string

See Also:

Constant Field Values

timestampPattern

public static String timestampPattern

localized format string for a timestamp

datePattern

public static String datePattern

localized format string for a date

timePattern

public static String timePattern

localized format string for a time

shortTimestampPattern

public static String shortTimestampPattern

localized format string for a short timestamp

shortDatePattern

public static String shortDatePattern

localized format string for a short date

shortTimePattern

public static String shortTimePattern

localized format string for a short time

timestampFormat

public static DateFormat timestampFormat

localized DateFormat for a timestamp

dateFormat

public static DateFormat dateFormat

localized DateFormat for a date

timeFormat

public static DateFormat timeFormat

localized DateFormat for a time

shortTimestampFormat

public static DateFormat shortTimestampFormat

localized DateFormat for a short timestamp

shortDateFormat

public static DateFormat shortDateFormat

localized DateFormat for a short date

shortTimeFormat

public static DateFormat shortTimeFormat

localized DateFormat for a short time

debitLetter

public static char debitLetter

short letter for "debit" (soll)

creditLetter

public static char creditLetter

short letter for "credit" (haben)

emptyString

public static final String emptyString

the empty string

See Also:

Constant Field Values

lineSeparatorString

public static final String lineSeparatorString

the newline string

See Also:

Constant Field Values

stringNormalizer

public static StringConverter stringNormalizer

The default normalizer used within the application. Defaults to DefaultStringNormalizer.

MD5SALT

public static char[] MD5SALT

Salt for md5sum(char[]).
The default is null, i.e. no salt. Applications should set an individual salt to enhance security.

Constructor Detail

StringHelper

public StringHelper()

Method Detail

loadFormats

public static void loadFormats()

Loads the localized formats. Invoked whenever the Locale changes.

unDiacrit

public static String unDiacrit(String str)

Converts special unicode characters (so-called diacrits) to standard ascii. Supports also special german and northern european "umlauts".

Parameters:

str - the string to be converted

Returns:

the converted string

normalize

public static String normalize(String str,
                               StringConverter normalizer)

Normalizes a string (phonetically) for use as AppDbObject.normText.

Parameters:

str - the string to be normalized

normalizer - the normalizer to use, null = global default

Returns:

the normalized string

normalize

public static String normalize(String str)

Normalizes a string (phonetically) for use as AppDbObject.normText using stringNormalizer.

Parameters:

str - the string to be normalized

Returns:

the normalized string

toDoubleQuotes

public static String toDoubleQuotes(String str)

Takes a string, surrounds it with double-quotes and escapes all double-quotes already in the string according to Unix rules. Example:

 Length 5" --> "Length 5\""
 

Parameters:

str - the string

Returns:

the string in double quotes

toWindowsDoubleQuotes

public static String toWindowsDoubleQuotes(String str)

Takes a string, surrounds it with double-quotes and escapes all double-quotes already in the string according to Windows-rules. Example:

 Length 5" --> "Length 5""
 

Parameters:

str - the string

Returns:

the string in double quotes

toFixedLength

public static String toFixedLength(String str,
                                   int length,
                                   char filler)

Takes a string and returns one with a given length, cutting or filling up with fillchars, whatever appropriate.

Parameters:

str - the string

length - the length of the returned string

filler - the character to fill up if str is too short

Returns:

the string with the desired length

toFixedLength

public static String toFixedLength(String str,
                                   int length)

Takes a string and returns one with a given length, cutting or filling up with spaces, whatever appropriate.

Parameters:

str - the string

length - the length of the returned string

Returns:

the string with the desired length

toFixedLengthLeftFill

public static String toFixedLengthLeftFill(String str,
                                           int length,
                                           char filler)

Takes a string and returns one with a given length, cutting or filling up with fillchars from the left, whatever appropriate.

Parameters:

str - the string

length - the length of the returned string

filler - the character to fill up if str is too short

Returns:

the string with the desired length

toFixedLengthLeftFill

public static String toFixedLengthLeftFill(String str,
                                           int length)

Takes a string and returns one with a given length, cutting or filling up with spaces from the left, whatever appropriate.

Parameters:

str - the string

length - the length of the returned string

Returns:

the string with the desired length

toDTA

public static String toDTA(String str)

Filters illegal chars for DTA-Files (German "DATENAUSTAUSCH" banking format).

Parameters:

str - the string

Returns:

the DTA conform string

toVarName

public static String toVarName(String str)

Filters illegal chars for Java variable names.

Parameters:

str - the string

Returns:

the java conform string

isAllDigits

public static boolean isAllDigits(String str,
                                  boolean whitespaceAllowed)

Checks if a string contains only digits or whitespaces, i.e. no illegal char in a number string.

Parameters:

str - the string to check

whitespaceAllowed - true if whitespaces are allowed

Returns:

true if no illegal char detected, false otherwise

isAllDigits

public static boolean isAllDigits(String str)

checks if a string contains only digits, i.e. no non-number char in string, even no whitespace.

Parameters:

str - the string to check

Returns:

true if no illegal char detected, false otherwise

debitCreditToString

public static String debitCreditToString(BMoney money,
                                         boolean debit)

Translates a money value to a string with a suffix indicating whether debit or credit. Commonly used in financial accounting applications.

Parameters:

money - the amount of money

debit - true if the amount is debit

Returns:

the formatted value

trim

public static String trim(String s,
                          int max)

Trims a string. The method is nullpointer safe.

Parameters:

s - the string, may be null

max - the maximum number of characters, 0 = minimum length

Returns:

the trimmed string, null if s == null

trim

public static String trim(String s)

Trims a string. The method is nullpointer safe.

Parameters:

s - the string, may be null

Returns:

the trimmed string, null if s == null

See Also:

trim(java.lang.String, int)

isAllWhitespace

public static boolean isAllWhitespace(String str)

Checks if string contains only whitespaces.

Parameters:

str - the string to check

Returns:

true if null, empty or all whitespace, false if at least one non-whitespace-character found

firstLine

public static String firstLine(String str)

Gets the first line from a multi-line string. Nice in tables.

Parameters:

str - the multiline string

Returns:

the first line, null if str == null

toHexString

public static String toHexString(byte[] binaryData)

Creates a human-readable hex-String out of a byte-array (e.g. from MessageDigest MD5sum).

Parameters:

binaryData - the data, may be null

Returns:

the formatted hex string , null if data was null

toBytes

public static byte[] toBytes(char c)

Converts a single (unicode) char to a byte-array.

Parameters:

c - the character

Returns:

the byte[2] array

toBytes

public static byte[] toBytes(char[] chars)

Converts a char-array to a byte-array.

Parameters:

chars - the character array

Returns:

the byte array

md5sum

public static String md5sum(char[] salt,
                            char[] input)

Builds an MD5-sum from an array of chars as used in password-fields.
Note that this method converts the characters to bytes via toBytes(char[]) before applying the md5 hash. By this we achieve an enhanced security against md5 crackers, which assume ordinary strings. In order to enhance security even more, however, you should add some application-specific salt.

Parameters:

salt - the "salt", null if plain MD5.

input - is the input array of chars

Returns:

the md5sum as a string, null if input == null or conversion failed (error is logged)

See Also:

md5sum(char[]), MD5SALT

md5sum

public static String md5sum(char[] input)

Builds an MD5-sum from an array of chars with a default salt given by MD5SALT.

Parameters:

input - is the input array of chars

Returns:

the md5sum as a string, null if input == null or conversion failed (error is logged)

toString

public static String toString(String str)

Maps null to the empty string. Simple but essential ;)

Parameters:

str - the string to test against null

Returns:

str or the emptystring if str is null

getClassBaseName

public static String getClassBaseName(String str)

Gets the basename of a classname(-like) string. The basename is the last name of a pathname with dots.

Parameters:

str - the classname

Returns:

the basename

getClassBaseName

public static String getClassBaseName(Class<?> clazz)

Gets the basename of a class. The basename is the class name without the package.

Parameters:

clazz - the class

Returns:

the basename

See Also:

getClassBaseName(java.lang.String)

objectArrayToString

public static String objectArrayToString(Object[] objArray,
                                         String separator)

Creates a string from an object array.

Parameters:

objArray - the array of objects

separator - the string between two objects

Returns:

the string

toCharArray

public static char[] toCharArray(String str)

Transforms a string to a char-array. nullp-safe.

Parameters:

str - the string

Returns:

the character array

toHTML

public static String toHTML(String text)

Converts a multiline string to an HTML-string that can be displayed in a label. Useful to print multiline labels.

Parameters:

text - the input string

Returns:

the HTML string