org.owasp.esapi
Class StringUtilities

java.lang.Object
  org.owasp.esapi.StringUtilities

public class StringUtilities
extends java.lang.Object

String utilities used in various filters.

Since:

June 1, 2007

Author:

Jeff Williams (jeff.williams .at. aspectsecurity.com) Aspect Security

Constructor Summary

StringUtilities()

Method Summary

static boolean	contains(java.lang.StringBuilder input, char c) Returns true if the character is contained in the provided StringBuilder.
static int	getLevenshteinDistance(java.lang.String s, java.lang.String t) Calculate the Edit Distance between 2 Strings as a measure of similarity.
static boolean	isEmpty(java.lang.String str) Returns true if String is empty ("") or null.
static boolean	notNullOrEmpty(java.lang.String str, boolean trim) Check to ensure that a String is not null or empty (after optional trimming of leading and trailing whitespace).
static java.lang.String	replaceLinearWhiteSpace(java.lang.String input)
static java.lang.String	replaceNull(java.lang.String test, java.lang.String replace) Returns the replace value if the value of test is null, "null", or ""
static java.lang.String	stripControls(java.lang.String input) Removes all unprintable characters from a string and replaces with a space.
static char[]	union(char[]... list) Union multiple character arrays.

Methods inherited from class java.lang.Object

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

Constructor Detail

StringUtilities

public StringUtilities()

Method Detail

replaceLinearWhiteSpace

public static java.lang.String replaceLinearWhiteSpace(java.lang.String input)

stripControls

public static java.lang.String stripControls(java.lang.String input)

Removes all unprintable characters from a string and replaces with a space.

Parameters:

input -

Returns:

the stripped value

union

public static char[] union(char[]... list)

Union multiple character arrays.

Parameters:

list - the char[]s to union

Returns:

the union of the char[]s

contains

public static boolean contains(java.lang.StringBuilder input,
                               char c)

Returns true if the character is contained in the provided StringBuilder.

Parameters:

input - The input

c - The character to check for to see if input contains.

Returns:

True if the specified character is contained; false otherwise.

replaceNull

public static java.lang.String replaceNull(java.lang.String test,
                                           java.lang.String replace)

Returns the replace value if the value of test is null, "null", or ""

Parameters:

test - The value to test

replace - The replacement value

Returns:

The correct value

getLevenshteinDistance

public static int getLevenshteinDistance(java.lang.String s,
                                         java.lang.String t)

Calculate the Edit Distance between 2 Strings as a measure of similarity. For example, if the strings GUMBO and GAMBOL are passed in, the edit distance is 2, since GUMBO transforms into GAMBOL by replacing the 'U' with an 'A' and adding an 'L'. Original Implementation of this algorithm by Michael Gilleland, adapted by Chas Emerick for the Apache-Commons project http://www.merriampark.com/ldjava.htm

Parameters:

s - The source string

t - The target String

Returns:

The edit distance between the 2 strings

notNullOrEmpty

public static boolean notNullOrEmpty(java.lang.String str,
                                     boolean trim)

Check to ensure that a String is not null or empty (after optional trimming of leading and trailing whitespace). Usually used with assertions, as in

                assert StringUtils.notNullOrEmpty(cipherXform, true) :
                                                                "Cipher transformation may not be null or empty!";
 

Parameters:

str - The String to be checked.

trim - If true, the string is first trimmed before checking to see if it is empty, otherwise it is not.

Returns:

True if the string is null or empty (after possible trimming); otherwise false.

Since:

2.0

isEmpty

public static boolean isEmpty(java.lang.String str)

Returns true if String is empty ("") or null.