StringUtils (HtmlUnit 4.18.0 API)

java.lang.Object
- org.htmlunit.util.StringUtils

```
public final class StringUtils
extends Object
```
String utilities class for utility functions not covered by third party libraries.

Author:

Daniel Gredler, Ahmed Ashour, Martin Tamme, Ronald Brill

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static Color`	`asColorHexadecimal(String token)` Returns a Color parsed from the given RGB in hexadecimal notation.
`static boolean`	`containsIgnoreCase(String s, String expected)` Tests if a CharSequence ends with a specified prefix.
`static String`	`cssCamelize(String string)` Transforms the specified string from delimiter-separated (e.g.
`static String`	`cssDeCamelize(String string)` Transforms the specified string from camel-cased (e.g.
`static <T extends CharSequence> T`	`defaultIfEmptyOrNull(T s, T defaultString)` Returns either the passed in CharSequence, or if the CharSequence is empty or `null`, the default value.
`static boolean`	`endsWithIgnoreCase(String s, String expectedEnd)` Tests if a CharSequence ends with a specified prefix.
`static boolean`	`equalsChar(char expected, CharSequence s)`
`static String`	`escapeXml(String text)` Escape the string to be used as xml 1.0 content be replacing the characters '"', '&', ''', '<', and '>' into their XML entity equivalents.
`static String`	`escapeXmlAttributeValue(String attValue)` Escape the string to be used as attribute value.
`static String`	`escapeXmlChars(String s)` Escapes the characters '<', '>' and '&' into their XML entity equivalents.
`static Color`	`findColorHSL(String token)` Returns a Color parsed from the given hsl notation if found inside the given string.
`static Color`	`findColorRGB(String token)` Returns a Color parsed from the given rgb notation if found inside the given string.
`static Color`	`findColorRGBA(String token)` Returns a Color parsed from the given rgb notation.
`static String`	`formatColor(Color color)` Formats the specified color.
`static int`	`indexOf(String s, char searchChar, int beginIndex, int endIndex)` Returns the index within the specified string of the first occurrence of the specified search character.
`static boolean`	`isBlank(CharSequence s)` Tests if a CharSequence is null, empty, or contains only whitespace.
`static boolean`	`isEmptyOrNull(CharSequence s)` Returns true if the param is null or empty.
`static boolean`	`isEmptyString(CharSequence s)` Returns true if the param is not null and empty.
`static boolean`	`isNotBlank(CharSequence s)` Tests if a CharSequence is NOT null, empty, or contains only whitespace.
`static String`	`replaceChars(String str, String searchChars, String replaceChars)` Replaces multiple characters in a String in one go.
`static String`	`sanitizeForAppendReplacement(String toSanitize)` Sanitize a string for use in Matcher.appendReplacement.
`static String`	`sanitizeForFileName(String toSanitize)` Sanitizes a string for use as filename.
`static String[]`	`splitAtBlank(String str)` Splits the provided text into an array, using blank as the separator.
`static String[]`	`splitAtComma(String str)` Splits the provided text into an array, using blank as the separator.
`static String[]`	`splitAtCommaOrBlank(String str)` Splits the provided text into an array, using comma or blank as the separator.
`static String[]`	`splitAtJavaWhitespace(String str)` Splits the provided text into an array, using whitespace as the separator.
`static boolean`	`startsWithIgnoreCase(String s, String expectedStart)` Tests if a CharSequence starts with a specified prefix.
`static String`	`substringBefore(String str, String find)` Gets the substring before the first occurrence of a separator.
`static byte[]`	`toByteArray(String content, Charset charset)` Converts a string into a byte array using the specified encoding.
`static String`	`toRootLowerCase(String s)` Lowercases a string by checking and check for null first.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - isEmptyString
```
public static boolean isEmptyString(CharSequence s)
```
    Returns true if the param is not null and empty. This is different from StringUtils.isEmpty(CharSequence) because this returns false if the provided string is null.
    
    Parameters:
    
    s - the string to check
    
    Returns:
    
    true if the param is not null and empty
  - isEmptyOrNull
```
public static boolean isEmptyOrNull(CharSequence s)
```
    Returns true if the param is null or empty.
    
    Parameters:
    
    s - the string to check
    
    Returns:
    
    true if the param is null or empty
  - defaultIfEmptyOrNull
```
public static <T extends CharSequence> T defaultIfEmptyOrNull(T s,
                                                              T defaultString)
```
    Returns either the passed in CharSequence, or if the CharSequence is empty or null, the default value.
    
    Type Parameters:
    
    T - the kind of CharSequence
    
    Parameters:
    
    s - the CharSequence to check
    
    defaultString - the default to return if the input is empty or null
    
    Returns:
    
    the passed in CharSequence, or the defaultString
  - isBlank
```
public static boolean isBlank(CharSequence s)
```
    Tests if a CharSequence is null, empty, or contains only whitespace.
    
    Parameters:
    
    s - the CharSequence to check
    
    Returns:
    
    true if a CharSequence is null, empty, or contains only whitespace
  - isNotBlank
```
public static boolean isNotBlank(CharSequence s)
```
    Tests if a CharSequence is NOT null, empty, or contains only whitespace.
    
    Parameters:
    
    s - the CharSequence to check
    
    Returns:
    
    false if a CharSequence is null, empty, or contains only whitespace
  - equalsChar
```
public static boolean equalsChar(char expected,
                                 CharSequence s)
```
    Parameters:
    
    expected - the char that we expect
    
    s - the string to check
    
    Returns:
    
    true if the provided string has only one char and this matches the expectation
  - startsWithIgnoreCase
```
public static boolean startsWithIgnoreCase(String s,
                                           String expectedStart)
```
    Tests if a CharSequence starts with a specified prefix.
    
    Parameters:
    
    s - the string to check
    
    expectedStart - the string that we expect at the beginning (has to be not null and not empty)
    
    Returns:
    
    true if the provided string has only one char and this matches the expectation
  - endsWithIgnoreCase
```
public static boolean endsWithIgnoreCase(String s,
                                         String expectedEnd)
```
    Tests if a CharSequence ends with a specified prefix.
    
    Parameters:
    
    s - the string to check
    
    expectedEnd - the string that we expect at the end (has to be not null and not empty)
    
    Returns:
    
    true if the provided string has only one char and this matches the expectation
  - containsIgnoreCase
```
public static boolean containsIgnoreCase(String s,
                                         String expected)
```
    Tests if a CharSequence ends with a specified prefix.
    
    Parameters:
    
    s - the string to check
    
    expected - the string that we expect to be a substring (has to be not null and not empty)
    
    Returns:
    
    true if the provided string has only one char and this matches the expectation
  - replaceChars
```
public static String replaceChars(String str,
                                  String searchChars,
                                  String replaceChars)
```
    Replaces multiple characters in a String in one go. This method can also be used to delete characters.
    
    Parameters:
    
    str - String to replace characters in, may be null.
    
    searchChars - a set of characters to search for, may be null.
    
    replaceChars - a set of characters to replace, may be null.
    
    Returns:
    
    modified String, or the input string if no replace was done.
  - escapeXmlChars
```
public static String escapeXmlChars(String s)
```
    Escapes the characters '<', '>' and '&' into their XML entity equivalents.
    
    Parameters:
    
    s - the string to escape
    
    Returns:
    
    the escaped form of the specified string
  - escapeXml
```
public static String escapeXml(String text)
```
    Escape the string to be used as xml 1.0 content be replacing the characters '"', '&', ''', '<', and '>' into their XML entity equivalents.
    
    Parameters:
    
    text - the attribute value
    
    Returns:
    
    the escaped value
  - escapeXmlAttributeValue
```
public static String escapeXmlAttributeValue(String attValue)
```
    Escape the string to be used as attribute value. Only <, & and " have to be escaped (see http://www.w3.org/TR/REC-xml/#d0e888).
    
    Parameters:
    
    attValue - the attribute value
    
    Returns:
    
    the escaped value
  - indexOf
```
public static int indexOf(String s,
                          char searchChar,
                          int beginIndex,
                          int endIndex)
```
    Returns the index within the specified string of the first occurrence of the specified search character.
    
    Parameters:
    
    s - the string to search
    
    searchChar - the character to search for
    
    beginIndex - the index at which to start the search
    
    endIndex - the index at which to stop the search
    
    Returns:
    
    the index of the first occurrence of the character in the string or -1
  - asColorHexadecimal
```
public static Color asColorHexadecimal(String token)
```
    Returns a Color parsed from the given RGB in hexadecimal notation.
    
    Parameters:
    
    token - the token to parse
    
    Returns:
    
    a Color whether the token is a color RGB in hexadecimal notation; otherwise null
  - findColorRGB
```
public static Color findColorRGB(String token)
```
    Returns a Color parsed from the given rgb notation if found inside the given string.
    
    Parameters:
    
    token - the token to parse
    
    Returns:
    
    a Color whether the token contains a color in RGB notation; otherwise null
  - findColorRGBA
```
public static Color findColorRGBA(String token)
```
    Returns a Color parsed from the given rgb notation.
    
    Parameters:
    
    token - the token to parse
    
    Returns:
    
    a Color whether the token is a color in RGB notation; otherwise null
  - findColorHSL
```
public static Color findColorHSL(String token)
```
    Returns a Color parsed from the given hsl notation if found inside the given string.
    
    Parameters:
    
    token - the token to parse
    
    Returns:
    
    a Color whether the token contains a color in RGB notation; otherwise null
  - formatColor
```
public static String formatColor(Color color)
```
    Formats the specified color.
    
    Parameters:
    
    color - the color to format
    
    Returns:
    
    the specified color, formatted
  - sanitizeForAppendReplacement
```
public static String sanitizeForAppendReplacement(String toSanitize)
```
    Sanitize a string for use in Matcher.appendReplacement. Replaces all \ with \\ and $ as \$ because they are used as control characters in appendReplacement.
    
    Parameters:
    
    toSanitize - the string to sanitize
    
    Returns:
    
    sanitized version of the given string
  - sanitizeForFileName
```
public static String sanitizeForFileName(String toSanitize)
```
    Sanitizes a string for use as filename. Replaces \, /, |, :, ?, *, ", <, >, control chars by _ (underscore).
    
    Parameters:
    
    toSanitize - the string to sanitize
    
    Returns:
    
    sanitized version of the given string
  - cssCamelize
```
public static String cssCamelize(String string)
```
    Transforms the specified string from delimiter-separated (e.g. font-size) to camel-cased (e.g. fontSize).
    
    Parameters:
    
    string - the string to camelize
    
    Returns:
    
    the transformed string
  - toRootLowerCase
```
public static String toRootLowerCase(String s)
```
    Lowercases a string by checking and check for null first. There is no cache involved and the ROOT locale is used to convert it.
    
    Parameters:
    
    s - the string to lowercase
    
    Returns:
    
    the lowercased string
  - cssDeCamelize
```
public static String cssDeCamelize(String string)
```
    Transforms the specified string from camel-cased (e.g. fontSize) to delimiter-separated (e.g. font-size). to camel-cased .
    
    Parameters:
    
    string - the string to decamelize
    
    Returns:
    
    the transformed string
  - toByteArray
```
public static byte[] toByteArray(String content,
                                 Charset charset)
```
    Converts a string into a byte array using the specified encoding.
    
    Parameters:
    
    charset - the charset
    
    content - the string to convert
    
    Returns:
    
    the String as a byte[]; if the specified encoding is not supported an empty byte[] will be returned
  - splitAtJavaWhitespace
```
public static String[] splitAtJavaWhitespace(String str)
```
    Splits the provided text into an array, using whitespace as the separator. Whitespace is defined by Character.isWhitespace(char).
    
    Parameters:
    
    str - the String to parse, may be null
    
    Returns:
    
    an array of parsed Strings, an empty array if null String input
  - splitAtBlank
```
public static String[] splitAtBlank(String str)
```
    Splits the provided text into an array, using blank as the separator.
    
    Parameters:
    
    str - the String to parse, may be null
    
    Returns:
    
    an array of parsed Strings, an empty array if null String input
  - splitAtComma
```
public static String[] splitAtComma(String str)
```
    Splits the provided text into an array, using blank as the separator.
    
    Parameters:
    
    str - the String to parse, may be null
    
    Returns:
    
    an array of parsed Strings, an empty array if null String input
  - splitAtCommaOrBlank
```
public static String[] splitAtCommaOrBlank(String str)
```
    Splits the provided text into an array, using comma or blank as the separator.
    
    Parameters:
    
    str - the String to parse, may be null
    
    Returns:
    
    an array of parsed Strings, an empty array if null String input
  - substringBefore
```
public static String substringBefore(String str,
                                     String find)
```
    Gets the substring before the first occurrence of a separator. The separator is not returned. A null string input will return null. An empty ("") string input will return the empty string. A null or empty separator is not allowed (will throw).
    
    Parameters:
    
    str - the String to get a substring from, may be null.
    
    find - the String to find, not null and not empty
    
    Returns:
    
    the substring before the first occurrence of the specified string, null if null String input.

Class StringUtils

Method Summary

Methods inherited from class java.lang.Object

Method Detail

isEmptyString

isEmptyOrNull

defaultIfEmptyOrNull

isBlank

isNotBlank

equalsChar

startsWithIgnoreCase

endsWithIgnoreCase

containsIgnoreCase

replaceChars

escapeXmlChars

escapeXml

escapeXmlAttributeValue

indexOf

asColorHexadecimal

findColorRGB

findColorRGBA

findColorHSL

formatColor

sanitizeForAppendReplacement

sanitizeForFileName

cssCamelize

toRootLowerCase

cssDeCamelize

toByteArray

splitAtJavaWhitespace

splitAtBlank

splitAtComma

splitAtCommaOrBlank

substringBefore