StringUtils (Spring Framework 5.3.35 API)

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

```
public abstract class StringUtils
extends Object
```
Miscellaneous String utility methods.
Mainly for internal use within the framework; consider Apache's Commons Lang for a more comprehensive suite of String utilities.
This class delivers some simple functionality that should really be provided by the core Java String and StringBuilder classes. It also provides easy-to-use methods to convert between delimited strings, such as CSV strings, and collections and arrays.

Since:

16 April 2001

Author:

Rod Johnson, Juergen Hoeller, Keith Donald, Rob Harrop, Rick Evans, Arjen Poutsma, Sam Brannen, Brian Clozel

Constructor Summary

Constructors
Constructor and Description

StringUtils()

Constructors
Constructor and Description
`StringUtils()`

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static String[]`	`addStringToArray(String[] array, String str)` Append the given `String` to the given `String` array, returning a new array consisting of the input array contents plus the given `String`.
`static String`	`applyRelativePath(String path, String relativePath)` Apply the given relative path to the given Java resource path, assuming standard Java folder separation (i.e.
`static String`	`arrayToCommaDelimitedString(Object[] arr)` Convert a `String` array into a comma delimited `String` (i.e., CSV).
`static String`	`arrayToDelimitedString(Object[] arr, String delim)` Convert a `String` array into a delimited `String` (e.g.
`static String`	`capitalize(String str)` Capitalize a `String`, changing the first letter to upper case as per `Character.toUpperCase(char)`.
`static String`	`cleanPath(String path)` Normalize the path by suppressing sequences like "path/.." and inner simple dots.
`static String`	`collectionToCommaDelimitedString(Collection<?> coll)` Convert a `Collection` into a delimited `String` (e.g., CSV).
`static String`	`collectionToDelimitedString(Collection<?> coll, String delim)` Convert a `Collection` into a delimited `String` (e.g.
`static String`	`collectionToDelimitedString(Collection<?> coll, String delim, String prefix, String suffix)` Convert a `Collection` to a delimited `String` (e.g.
`static Set<String>`	`commaDelimitedListToSet(String str)` Convert a comma delimited list (e.g., a row from a CSV file) into a set.
`static String[]`	`commaDelimitedListToStringArray(String str)` Convert a comma delimited list (e.g., a row from a CSV file) into an array of strings.
`static String[]`	`concatenateStringArrays(String[] array1, String[] array2)` Concatenate the given `String` arrays into one, with overlapping array elements included twice.
`static boolean`	`containsWhitespace(CharSequence str)` Check whether the given `CharSequence` contains any whitespace characters.
`static boolean`	`containsWhitespace(String str)` Check whether the given `String` contains any whitespace characters.
`static int`	`countOccurrencesOf(String str, String sub)` Count the occurrences of the substring `sub` in string `str`.
`static String`	`delete(String inString, String pattern)` Delete all occurrences of the given substring.
`static String`	`deleteAny(String inString, String charsToDelete)` Delete any character in a given `String`.
`static String[]`	`delimitedListToStringArray(String str, String delimiter)` Take a `String` that is a delimited list and convert it into a `String` array.
`static String[]`	`delimitedListToStringArray(String str, String delimiter, String charsToDelete)` Take a `String` that is a delimited list and convert it into a `String` array.
`static boolean`	`endsWithIgnoreCase(String str, String suffix)` Test if the given `String` ends with the specified suffix, ignoring upper/lower case.
`static String`	`getFilename(String path)` Extract the filename from the given Java resource path, e.g.
`static String`	`getFilenameExtension(String path)` Extract the filename extension from the given Java resource path, e.g.
`static boolean`	`hasLength(CharSequence str)` Check that the given `CharSequence` is neither `null` nor of length 0.
`static boolean`	`hasLength(String str)` Check that the given `String` is neither `null` nor of length 0.
`static boolean`	`hasText(CharSequence str)` Check whether the given `CharSequence` contains actual text.
`static boolean`	`hasText(String str)` Check whether the given `String` contains actual text.
`static boolean`	`isEmpty(Object str)` Deprecated. as of 5.3, in favor of `hasLength(String)` and `hasText(String)` (or `ObjectUtils.isEmpty(Object)`)
`static boolean`	`matchesCharacter(String str, char singleCharacter)` Test if the given `String` matches the given single character.
`static String[]`	`mergeStringArrays(String[] array1, String[] array2)` Deprecated. as of 4.3.15, in favor of manual merging via `LinkedHashSet` (with every entry included at most once, even entries within the first array)
`static Locale`	`parseLocale(String localeValue)` Parse the given `String` value into a `Locale`, accepting the `Locale.toString()` format as well as BCP 47 language tags as specified by `Locale.forLanguageTag(java.lang.String)`.
`static Locale`	`parseLocaleString(String localeString)` Parse the given `String` representation into a `Locale`.
`static TimeZone`	`parseTimeZoneString(String timeZoneString)` Parse the given `timeZoneString` value into a `TimeZone`.
`static boolean`	`pathEquals(String path1, String path2)` Compare two paths after normalization of them.
`static String`	`quote(String str)` Quote the given `String` with single quotes.
`static Object`	`quoteIfString(Object obj)` Turn the given Object into a `String` with single quotes if it is a `String`; keeping the Object as-is else.
`static String[]`	`removeDuplicateStrings(String[] array)` Remove duplicate strings from the given array.
`static String`	`replace(String inString, String oldPattern, String newPattern)` Replace all occurrences of a substring within a string with another string.
`static String[]`	`sortStringArray(String[] array)` Sort the given `String` array if necessary.
`static String[]`	`split(String toSplit, String delimiter)` Split a `String` at the first occurrence of the delimiter.
`static Properties`	`splitArrayElementsIntoProperties(String[] array, String delimiter)` Take an array of strings and split each element based on the given delimiter.
`static Properties`	`splitArrayElementsIntoProperties(String[] array, String delimiter, String charsToDelete)` Take an array of strings and split each element based on the given delimiter.
`static boolean`	`startsWithIgnoreCase(String str, String prefix)` Test if the given `String` starts with the specified prefix, ignoring upper/lower case.
`static String`	`stripFilenameExtension(String path)` Strip the filename extension from the given Java resource path, e.g.
`static boolean`	`substringMatch(CharSequence str, int index, CharSequence substring)` Test whether the given string matches the given substring at the given index.
`static String[]`	`tokenizeToStringArray(String str, String delimiters)` Tokenize the given `String` into a `String` array via a `StringTokenizer`.
`static String[]`	`tokenizeToStringArray(String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens)` Tokenize the given `String` into a `String` array via a `StringTokenizer`.
`static String`	`toLanguageTag(Locale locale)` Deprecated. as of 5.0.4, in favor of `Locale.toLanguageTag()`
`static String[]`	`toStringArray(Collection<String> collection)` Copy the given `Collection` into a `String` array.
`static String[]`	`toStringArray(Enumeration<String> enumeration)` Copy the given `Enumeration` into a `String` array.
`static CharSequence`	`trimAllWhitespace(CharSequence str)` Trim all whitespace from the given `CharSequence`: leading, trailing, and in between characters.
`static String`	`trimAllWhitespace(String str)` Trim all whitespace from the given `String`: leading, trailing, and in between characters.
`static String[]`	`trimArrayElements(String[] array)` Trim the elements of the given `String` array, calling `String.trim()` on each non-null element.
`static String`	`trimLeadingCharacter(String str, char leadingCharacter)` Trim all occurrences of the supplied leading character from the given `String`.
`static String`	`trimLeadingWhitespace(String str)` Trim leading whitespace from the given `String`.
`static String`	`trimTrailingCharacter(String str, char trailingCharacter)` Trim all occurrences of the supplied trailing character from the given `String`.
`static String`	`trimTrailingWhitespace(String str)` Trim trailing whitespace from the given `String`.
`static String`	`trimWhitespace(String str)` Trim leading and trailing whitespace from the given `String`.
`static String`	`truncate(CharSequence charSequence)` Truncate the supplied `CharSequence`.
`static String`	`truncate(CharSequence charSequence, int threshold)` Truncate the supplied `CharSequence`.
`static String`	`uncapitalize(String str)` Uncapitalize a `String`, changing the first letter to lower case as per `Character.toLowerCase(char)`.
`static String`	`unqualify(String qualifiedName)` Unqualify a string qualified by a '.' dot character.
`static String`	`unqualify(String qualifiedName, char separator)` Unqualify a string qualified by a separator character.
`static String`	`uriDecode(String source, Charset charset)` Decode the given encoded URI component value.

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

- Constructor Detail
  - StringUtils
```
public StringUtils()
```
- Method Detail
  - isEmpty
```
@Deprecated
public static boolean isEmpty(@Nullable
                                          Object str)
```
    Deprecated. as of 5.3, in favor of hasLength(String) and hasText(String) (or ObjectUtils.isEmpty(Object))
    
    Check whether the given object (possibly a String) is empty. This is effectively a shortcut for !hasLength(String).
    This method accepts any Object as an argument, comparing it to null and the empty String. As a consequence, this method will never return true for a non-null non-String object.
    The Object signature is useful for general attribute handling code that commonly deals with Strings but generally has to iterate over Objects since attributes may e.g. be primitive value objects as well.
    Note: If the object is typed to String upfront, prefer hasLength(String) or hasText(String) instead.
    
    Parameters:
    
    str - the candidate object (possibly a String)
    
    Since:
    
    3.2.1
  - hasLength
```
public static boolean hasLength(@Nullable
                                CharSequence str)
```
    Check that the given CharSequence is neither null nor of length 0.
    Note: this method returns true for a CharSequence that purely consists of whitespace.
```
 StringUtils.hasLength(null) = false
 StringUtils.hasLength("") = false
 StringUtils.hasLength(" ") = true
 StringUtils.hasLength("Hello") = true
 
```
    Parameters:
    
    str - the CharSequence to check (may be null)
    
    Returns:
    
    true if the CharSequence is not null and has length
    
    See Also:
    
    hasLength(String), hasText(CharSequence)
  - hasLength
```
public static boolean hasLength(@Nullable
                                String str)
```
    Check that the given String is neither null nor of length 0.
    Note: this method returns true for a String that purely consists of whitespace.
    
    Parameters:
    
    str - the String to check (may be null)
    
    Returns:
    
    true if the String is not null and has length
    
    See Also:
    
    hasLength(CharSequence), hasText(String)
  - hasText
```
public static boolean hasText(@Nullable
                              CharSequence str)
```
    Check whether the given CharSequence contains actual text.
    More specifically, this method returns true if the CharSequence is not null, its length is greater than 0, and it contains at least one non-whitespace character.
```
 StringUtils.hasText(null) = false
 StringUtils.hasText("") = false
 StringUtils.hasText(" ") = false
 StringUtils.hasText("12345") = true
 StringUtils.hasText(" 12345 ") = true
 
```
    Parameters:
    
    str - the CharSequence to check (may be null)
    
    Returns:
    
    true if the CharSequence is not null, its length is greater than 0, and it does not contain whitespace only
    
    See Also:
    
    hasText(String), hasLength(CharSequence), Character.isWhitespace(char)
  - hasText
```
public static boolean hasText(@Nullable
                              String str)
```
    Check whether the given String contains actual text.
    More specifically, this method returns true if the String is not null, its length is greater than 0, and it contains at least one non-whitespace character.
    
    Parameters:
    
    str - the String to check (may be null)
    
    Returns:
    
    true if the String is not null, its length is greater than 0, and it does not contain whitespace only
    
    See Also:
    
    hasText(CharSequence), hasLength(String), Character.isWhitespace(char)
  - containsWhitespace
```
public static boolean containsWhitespace(@Nullable
                                         CharSequence str)
```
    Check whether the given CharSequence contains any whitespace characters.
    
    Parameters:
    
    str - the CharSequence to check (may be null)
    
    Returns:
    
    true if the CharSequence is not empty and contains at least 1 whitespace character
    
    See Also:
    
    Character.isWhitespace(char)
  - containsWhitespace
```
public static boolean containsWhitespace(@Nullable
                                         String str)
```
    Check whether the given String contains any whitespace characters.
    
    Parameters:
    
    str - the String to check (may be null)
    
    Returns:
    
    true if the String is not empty and contains at least 1 whitespace character
    
    See Also:
    
    containsWhitespace(CharSequence)
  - trimWhitespace
```
public static String trimWhitespace(String str)
```
    Trim leading and trailing whitespace from the given String.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    the trimmed String
    
    See Also:
    
    Character.isWhitespace(char)
  - trimAllWhitespace
```
public static CharSequence trimAllWhitespace(CharSequence str)
```
    Trim all whitespace from the given CharSequence: leading, trailing, and in between characters.
    
    Parameters:
    
    str - the CharSequence to check
    
    Returns:
    
    the trimmed CharSequence
    
    Since:
    
    5.3.22
    
    See Also:
    
    trimAllWhitespace(String), Character.isWhitespace(char)
  - trimAllWhitespace
```
public static String trimAllWhitespace(String str)
```
    Trim all whitespace from the given String: leading, trailing, and in between characters.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    the trimmed String
    
    See Also:
    
    trimAllWhitespace(CharSequence), Character.isWhitespace(char)
  - trimLeadingWhitespace
```
public static String trimLeadingWhitespace(String str)
```
    Trim leading whitespace from the given String.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    the trimmed String
    
    See Also:
    
    Character.isWhitespace(char)
  - trimTrailingWhitespace
```
public static String trimTrailingWhitespace(String str)
```
    Trim trailing whitespace from the given String.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    the trimmed String
    
    See Also:
    
    Character.isWhitespace(char)
  - trimLeadingCharacter
```
public static String trimLeadingCharacter(String str,
                                          char leadingCharacter)
```
    Trim all occurrences of the supplied leading character from the given String.
    
    Parameters:
    
    str - the String to check
    
    leadingCharacter - the leading character to be trimmed
    
    Returns:
    
    the trimmed String
  - trimTrailingCharacter
```
public static String trimTrailingCharacter(String str,
                                           char trailingCharacter)
```
    Trim all occurrences of the supplied trailing character from the given String.
    
    Parameters:
    
    str - the String to check
    
    trailingCharacter - the trailing character to be trimmed
    
    Returns:
    
    the trimmed String
  - matchesCharacter
```
public static boolean matchesCharacter(@Nullable
                                       String str,
                                       char singleCharacter)
```
    Test if the given String matches the given single character.
    
    Parameters:
    
    str - the String to check
    
    singleCharacter - the character to compare to
    
    Since:
    
    5.2.9
  - startsWithIgnoreCase
```
public static boolean startsWithIgnoreCase(@Nullable
                                           String str,
                                           @Nullable
                                           String prefix)
```
    Test if the given String starts with the specified prefix, ignoring upper/lower case.
    
    Parameters:
    
    str - the String to check
    
    prefix - the prefix to look for
    
    See Also:
    
    String.startsWith(java.lang.String, int)
  - endsWithIgnoreCase
```
public static boolean endsWithIgnoreCase(@Nullable
                                         String str,
                                         @Nullable
                                         String suffix)
```
    Test if the given String ends with the specified suffix, ignoring upper/lower case.
    
    Parameters:
    
    str - the String to check
    
    suffix - the suffix to look for
    
    See Also:
    
    String.endsWith(java.lang.String)
  - substringMatch
```
public static boolean substringMatch(CharSequence str,
                                     int index,
                                     CharSequence substring)
```
    Test whether the given string matches the given substring at the given index.
    
    Parameters:
    
    str - the original string (or StringBuilder)
    
    index - the index in the original string to start matching against
    
    substring - the substring to match at the given index
  - countOccurrencesOf
```
public static int countOccurrencesOf(String str,
                                     String sub)
```
    Count the occurrences of the substring sub in string str.
    
    Parameters:
    
    str - string to search in
    
    sub - string to search for
  - replace
```
public static String replace(String inString,
                             String oldPattern,
                             @Nullable
                             String newPattern)
```
    Replace all occurrences of a substring within a string with another string.
    
    Parameters:
    
    inString - String to examine
    
    oldPattern - String to replace
    
    newPattern - String to insert
    
    Returns:
    
    a String with the replacements
  - delete
```
public static String delete(String inString,
                            String pattern)
```
    Delete all occurrences of the given substring.
    
    Parameters:
    
    inString - the original String
    
    pattern - the pattern to delete all occurrences of
    
    Returns:
    
    the resulting String
  - deleteAny
```
public static String deleteAny(String inString,
                               @Nullable
                               String charsToDelete)
```
    Delete any character in a given String.
    
    Parameters:
    
    inString - the original String
    
    charsToDelete - a set of characters to delete. E.g. "az\n" will delete 'a's, 'z's and new lines.
    
    Returns:
    
    the resulting String
  - quote
```
@Nullable
public static String quote(@Nullable
                                     String str)
```
    Quote the given String with single quotes.
    
    Parameters:
    
    str - the input String (e.g. "myString")
    
    Returns:
    
    the quoted String (e.g. "'myString'"), or null if the input was null
  - quoteIfString
```
@Nullable
public static Object quoteIfString(@Nullable
                                             Object obj)
```
    Turn the given Object into a String with single quotes if it is a String; keeping the Object as-is else.
    
    Parameters:
    
    obj - the input Object (e.g. "myString")
    
    Returns:
    
    the quoted String (e.g. "'myString'"), or the input object as-is if not a String
  - unqualify
```
public static String unqualify(String qualifiedName)
```
    Unqualify a string qualified by a '.' dot character. For example, "this.name.is.qualified", returns "qualified".
    
    Parameters:
    
    qualifiedName - the qualified name
  - unqualify
```
public static String unqualify(String qualifiedName,
                               char separator)
```
    Unqualify a string qualified by a separator character. For example, "this:name:is:qualified" returns "qualified" if using a ':' separator.
    
    Parameters:
    
    qualifiedName - the qualified name
    
    separator - the separator
  - capitalize
```
public static String capitalize(String str)
```
    Capitalize a String, changing the first letter to upper case as per Character.toUpperCase(char). No other letters are changed.
    
    Parameters:
    
    str - the String to capitalize
    
    Returns:
    
    the capitalized String
  - uncapitalize
```
public static String uncapitalize(String str)
```
    Uncapitalize a String, changing the first letter to lower case as per Character.toLowerCase(char). No other letters are changed.
    
    Parameters:
    
    str - the String to uncapitalize
    
    Returns:
    
    the uncapitalized String
  - getFilename
```
@Nullable
public static String getFilename(@Nullable
                                           String path)
```
    Extract the filename from the given Java resource path, e.g. "mypath/myfile.txt" → "myfile.txt".
    
    Parameters:
    
    path - the file path (may be null)
    
    Returns:
    
    the extracted filename, or null if none
  - getFilenameExtension
```
@Nullable
public static String getFilenameExtension(@Nullable
                                                    String path)
```
    Extract the filename extension from the given Java resource path, e.g. "mypath/myfile.txt" → "txt".
    
    Parameters:
    
    path - the file path (may be null)
    
    Returns:
    
    the extracted filename extension, or null if none
  - stripFilenameExtension
```
public static String stripFilenameExtension(String path)
```
    Strip the filename extension from the given Java resource path, e.g. "mypath/myfile.txt" → "mypath/myfile".
    
    Parameters:
    
    path - the file path
    
    Returns:
    
    the path with stripped filename extension
  - applyRelativePath
```
public static String applyRelativePath(String path,
                                       String relativePath)
```
    Apply the given relative path to the given Java resource path, assuming standard Java folder separation (i.e. "/" separators).
    
    Parameters:
    
    path - the path to start from (usually a full file path)
    
    relativePath - the relative path to apply (relative to the full file path above)
    
    Returns:
    
    the full file path that results from applying the relative path
  - cleanPath
```
public static String cleanPath(String path)
```
    Normalize the path by suppressing sequences like "path/.." and inner simple dots.
    The result is convenient for path comparison. For other uses, notice that Windows separators ("\") are replaced by simple slashes.
    NOTE that cleanPath should not be depended upon in a security context. Other mechanisms should be used to prevent path-traversal issues.
    
    Parameters:
    
    path - the original path
    
    Returns:
    
    the normalized path
  - pathEquals
```
public static boolean pathEquals(String path1,
                                 String path2)
```
    Compare two paths after normalization of them.
    
    Parameters:
    
    path1 - first path for comparison
    
    path2 - second path for comparison
    
    Returns:
    
    whether the two paths are equivalent after normalization
  - uriDecode
```
public static String uriDecode(String source,
                               Charset charset)
```
    Decode the given encoded URI component value. Based on the following rules:
    - Alphanumeric characters "a" through "z", "A" through "Z", and "0" through "9" stay the same.
    - Special characters "-", "_", ".", and "*" stay the same.
    - A sequence "%<i>xy</i>" is interpreted as a hexadecimal representation of the character.
    - For all other characters (including those already decoded), the output is undefined.
    Parameters:
    
    source - the encoded String
    
    charset - the character set
    
    Returns:
    
    the decoded value
    
    Throws:
    
    IllegalArgumentException - when the given source contains invalid encoded sequences
    
    Since:
    
    5.0
    
    See Also:
    
    URLDecoder.decode(String, String)
  - parseLocale
```
@Nullable
public static Locale parseLocale(String localeValue)
```
    Parse the given String value into a Locale, accepting the Locale.toString() format as well as BCP 47 language tags as specified by Locale.forLanguageTag(java.lang.String).
    
    Parameters:
    
    localeValue - the locale value: following either Locale's toString() format ("en", "en_UK", etc.), also accepting spaces as separators (as an alternative to underscores), or BCP 47 (e.g. "en-UK")
    
    Returns:
    
    a corresponding Locale instance, or null if none
    
    Throws:
    
    IllegalArgumentException - in case of an invalid locale specification
    
    Since:
    
    5.0.4
    
    See Also:
    
    parseLocaleString(java.lang.String), Locale.forLanguageTag(java.lang.String)
  - parseLocaleString
```
@Nullable
public static Locale parseLocaleString(String localeString)
```
    Parse the given String representation into a Locale.
    For many parsing scenarios, this is an inverse operation of Locale's toString, in a lenient sense. This method does not aim for strict Locale design compliance; it is rather specifically tailored for typical Spring parsing needs.
    Note: This delegate does not accept the BCP 47 language tag format. Please use parseLocale(java.lang.String) for lenient parsing of both formats.
    
    Parameters:
    
    localeString - the locale String: following Locale's toString() format ("en", "en_UK", etc.), also accepting spaces as separators (as an alternative to underscores)
    
    Returns:
    
    a corresponding Locale instance, or null if none
    
    Throws:
    
    IllegalArgumentException - in case of an invalid locale specification
  - toLanguageTag
```
@Deprecated
public static String toLanguageTag(Locale locale)
```
    Deprecated. as of 5.0.4, in favor of Locale.toLanguageTag()
    
    Determine the RFC 3066 compliant language tag, as used for the HTTP "Accept-Language" header.
    
    Parameters:
    
    locale - the Locale to transform to a language tag
    
    Returns:
    
    the RFC 3066 compliant language tag as String
  - parseTimeZoneString
```
public static TimeZone parseTimeZoneString(String timeZoneString)
```
    Parse the given timeZoneString value into a TimeZone.
    
    Parameters:
    
    timeZoneString - the time zone String, following TimeZone.getTimeZone(String) but throwing IllegalArgumentException in case of an invalid time zone specification
    
    Returns:
    
    a corresponding TimeZone instance
    
    Throws:
    
    IllegalArgumentException - in case of an invalid time zone specification
  - toStringArray
```
public static String[] toStringArray(@Nullable
                                     Collection<String> collection)
```
    Copy the given Collection into a String array.
    The Collection must contain String elements only.
    
    Parameters:
    
    collection - the Collection to copy (potentially null or empty)
    
    Returns:
    
    the resulting String array
  - toStringArray
```
public static String[] toStringArray(@Nullable
                                     Enumeration<String> enumeration)
```
    Copy the given Enumeration into a String array.
    The Enumeration must contain String elements only.
    
    Parameters:
    
    enumeration - the Enumeration to copy (potentially null or empty)
    
    Returns:
    
    the resulting String array
  - addStringToArray
```
public static String[] addStringToArray(@Nullable
                                        String[] array,
                                        String str)
```
    Append the given String to the given String array, returning a new array consisting of the input array contents plus the given String.
    
    Parameters:
    
    array - the array to append to (can be null)
    
    str - the String to append
    
    Returns:
    
    the new array (never null)
  - concatenateStringArrays
```
@Nullable
public static String[] concatenateStringArrays(@Nullable
                                                         String[] array1,
                                                         @Nullable
                                                         String[] array2)
```
    Concatenate the given String arrays into one, with overlapping array elements included twice.
    The order of elements in the original arrays is preserved.
    
    Parameters:
    
    array1 - the first array (can be null)
    
    array2 - the second array (can be null)
    
    Returns:
    
    the new array (null if both given arrays were null)
  - mergeStringArrays
```
@Deprecated
 @Nullable
public static String[] mergeStringArrays(@Nullable
                                                                String[] array1,
                                                                @Nullable
                                                                String[] array2)
```
    Deprecated. as of 4.3.15, in favor of manual merging via LinkedHashSet (with every entry included at most once, even entries within the first array)
    
    Merge the given String arrays into one, with overlapping array elements only included once.
    The order of elements in the original arrays is preserved (with the exception of overlapping elements, which are only included on their first occurrence).
    
    Parameters:
    
    array1 - the first array (can be null)
    
    array2 - the second array (can be null)
    
    Returns:
    
    the new array (null if both given arrays were null)
  - sortStringArray
```
public static String[] sortStringArray(String[] array)
```
    Sort the given String array if necessary.
    
    Parameters:
    
    array - the original array (potentially empty)
    
    Returns:
    
    the array in sorted form (never null)
  - trimArrayElements
```
public static String[] trimArrayElements(String[] array)
```
    Trim the elements of the given String array, calling String.trim() on each non-null element.
    
    Parameters:
    
    array - the original String array (potentially empty)
    
    Returns:
    
    the resulting array (of the same size) with trimmed elements
  - removeDuplicateStrings
```
public static String[] removeDuplicateStrings(String[] array)
```
    Remove duplicate strings from the given array.
    As of 4.2, it preserves the original order, as it uses a LinkedHashSet.
    
    Parameters:
    
    array - the String array (potentially empty)
    
    Returns:
    
    an array without duplicates, in natural sort order
  - split
```
@Nullable
public static String[] split(@Nullable
                                       String toSplit,
                                       @Nullable
                                       String delimiter)
```
    Split a String at the first occurrence of the delimiter. Does not include the delimiter in the result.
    
    Parameters:
    
    toSplit - the string to split (potentially null or empty)
    
    delimiter - to split the string up with (potentially null or empty)
    
    Returns:
    
    a two element array with index 0 being before the delimiter, and index 1 being after the delimiter (neither element includes the delimiter); or null if the delimiter wasn't found in the given input String
  - splitArrayElementsIntoProperties
```
@Nullable
public static Properties splitArrayElementsIntoProperties(String[] array,
                                                                    String delimiter)
```
    Take an array of strings and split each element based on the given delimiter. A Properties instance is then generated, with the left of the delimiter providing the key, and the right of the delimiter providing the value.
    Will trim both the key and value before adding them to the Properties.
    
    Parameters:
    
    array - the array to process
    
    delimiter - to split each element using (typically the equals symbol)
    
    Returns:
    
    a Properties instance representing the array contents, or null if the array to process was null or empty
  - splitArrayElementsIntoProperties
```
@Nullable
public static Properties splitArrayElementsIntoProperties(String[] array,
                                                                    String delimiter,
                                                                    @Nullable
                                                                    String charsToDelete)
```
    Take an array of strings and split each element based on the given delimiter. A Properties instance is then generated, with the left of the delimiter providing the key, and the right of the delimiter providing the value.
    Will trim both the key and value before adding them to the Properties instance.
    
    Parameters:
    
    array - the array to process
    
    delimiter - to split each element using (typically the equals symbol)
    
    charsToDelete - one or more characters to remove from each element prior to attempting the split operation (typically the quotation mark symbol), or null if no removal should occur
    
    Returns:
    
    a Properties instance representing the array contents, or null if the array to process was null or empty
  - tokenizeToStringArray
```
public static String[] tokenizeToStringArray(@Nullable
                                             String str,
                                             String delimiters)
```
    Tokenize the given String into a String array via a StringTokenizer.
    Trims tokens and omits empty tokens.
    The given delimiters string can consist of any number of delimiter characters. Each of those characters can be used to separate tokens. A delimiter is always a single character; for multi-character delimiters, consider using delimitedListToStringArray(java.lang.String, java.lang.String).
    
    Parameters:
    
    str - the String to tokenize (potentially null or empty)
    
    delimiters - the delimiter characters, assembled as a String (each of the characters is individually considered as a delimiter)
    
    Returns:
    
    an array of the tokens
    
    See Also:
    
    StringTokenizer, String.trim(), delimitedListToStringArray(java.lang.String, java.lang.String)
  - tokenizeToStringArray
```
public static String[] tokenizeToStringArray(@Nullable
                                             String str,
                                             String delimiters,
                                             boolean trimTokens,
                                             boolean ignoreEmptyTokens)
```
    Tokenize the given String into a String array via a StringTokenizer.
    The given delimiters string can consist of any number of delimiter characters. Each of those characters can be used to separate tokens. A delimiter is always a single character; for multi-character delimiters, consider using delimitedListToStringArray(java.lang.String, java.lang.String).
    
    Parameters:
    
    str - the String to tokenize (potentially null or empty)
    
    delimiters - the delimiter characters, assembled as a String (each of the characters is individually considered as a delimiter)
    
    trimTokens - trim the tokens via String.trim()
    
    ignoreEmptyTokens - omit empty tokens from the result array (only applies to tokens that are empty after trimming; StringTokenizer will not consider subsequent delimiters as token in the first place).
    
    Returns:
    
    an array of the tokens
    
    See Also:
    
    StringTokenizer, String.trim(), delimitedListToStringArray(java.lang.String, java.lang.String)
  - delimitedListToStringArray
```
public static String[] delimitedListToStringArray(@Nullable
                                                  String str,
                                                  @Nullable
                                                  String delimiter)
```
    Take a String that is a delimited list and convert it into a String array.
    A single delimiter may consist of more than one character, but it will still be considered as a single delimiter string, rather than as a bunch of potential delimiter characters, in contrast to tokenizeToStringArray(java.lang.String, java.lang.String).
    
    Parameters:
    
    str - the input String (potentially null or empty)
    
    delimiter - the delimiter between elements (this is a single delimiter, rather than a bunch individual delimiter characters)
    
    Returns:
    
    an array of the tokens in the list
    
    See Also:
    
    tokenizeToStringArray(java.lang.String, java.lang.String)
  - delimitedListToStringArray
```
public static String[] delimitedListToStringArray(@Nullable
                                                  String str,
                                                  @Nullable
                                                  String delimiter,
                                                  @Nullable
                                                  String charsToDelete)
```
    Take a String that is a delimited list and convert it into a String array.
    A single delimiter may consist of more than one character, but it will still be considered as a single delimiter string, rather than as a bunch of potential delimiter characters, in contrast to tokenizeToStringArray(java.lang.String, java.lang.String).
    
    Parameters:
    
    str - the input String (potentially null or empty)
    
    delimiter - the delimiter between elements (this is a single delimiter, rather than a bunch individual delimiter characters)
    
    charsToDelete - a set of characters to delete; useful for deleting unwanted line breaks: e.g. "\r\n\f" will delete all new lines and line feeds in a String
    
    Returns:
    
    an array of the tokens in the list
    
    See Also:
    
    tokenizeToStringArray(java.lang.String, java.lang.String)
  - commaDelimitedListToStringArray
```
public static String[] commaDelimitedListToStringArray(@Nullable
                                                       String str)
```
    Convert a comma delimited list (e.g., a row from a CSV file) into an array of strings.
    
    Parameters:
    
    str - the input String (potentially null or empty)
    
    Returns:
    
    an array of strings, or the empty array in case of empty input
  - commaDelimitedListToSet
```
public static Set<String> commaDelimitedListToSet(@Nullable
                                                  String str)
```
    Convert a comma delimited list (e.g., a row from a CSV file) into a set.
    Note that this will suppress duplicates, and as of 4.2, the elements in the returned set will preserve the original order in a LinkedHashSet.
    
    Parameters:
    
    str - the input String (potentially null or empty)
    
    Returns:
    
    a set of String entries in the list
    
    See Also:
    
    removeDuplicateStrings(String[])
  - collectionToDelimitedString
```
public static String collectionToDelimitedString(@Nullable
                                                 Collection<?> coll,
                                                 String delim,
                                                 String prefix,
                                                 String suffix)
```
    Convert a Collection to a delimited String (e.g. CSV).
    Useful for toString() implementations.
    
    Parameters:
    
    coll - the Collection to convert (potentially null or empty)
    
    delim - the delimiter to use (typically a ",")
    
    prefix - the String to start each element with
    
    suffix - the String to end each element with
    
    Returns:
    
    the delimited String
  - collectionToDelimitedString
```
public static String collectionToDelimitedString(@Nullable
                                                 Collection<?> coll,
                                                 String delim)
```
    Convert a Collection into a delimited String (e.g. CSV).
    Useful for toString() implementations.
    
    Parameters:
    
    coll - the Collection to convert (potentially null or empty)
    
    delim - the delimiter to use (typically a ",")
    
    Returns:
    
    the delimited String
  - collectionToCommaDelimitedString
```
public static String collectionToCommaDelimitedString(@Nullable
                                                      Collection<?> coll)
```
    Convert a Collection into a delimited String (e.g., CSV).
    Useful for toString() implementations.
    
    Parameters:
    
    coll - the Collection to convert (potentially null or empty)
    
    Returns:
    
    the delimited String
  - arrayToDelimitedString
```
public static String arrayToDelimitedString(@Nullable
                                            Object[] arr,
                                            String delim)
```
    Convert a String array into a delimited String (e.g. CSV).
    Useful for toString() implementations.
    
    Parameters:
    
    arr - the array to display (potentially null or empty)
    
    delim - the delimiter to use (typically a ",")
    
    Returns:
    
    the delimited String
  - arrayToCommaDelimitedString
```
public static String arrayToCommaDelimitedString(@Nullable
                                                 Object[] arr)
```
    Convert a String array into a comma delimited String (i.e., CSV).
    Useful for toString() implementations.
    
    Parameters:
    
    arr - the array to display (potentially null or empty)
    
    Returns:
    
    the delimited String
  - truncate
```
public static String truncate(CharSequence charSequence)
```
    Truncate the supplied CharSequence.
    Delegates to truncate(CharSequence, int), supplying 100 as the threshold.
    
    Parameters:
    
    charSequence - the CharSequence to truncate
    
    Returns:
    
    a truncated string, or a string representation of the original CharSequence if its length does not exceed the threshold
    
    Since:
    
    5.3.27
  - truncate
```
public static String truncate(CharSequence charSequence,
                              int threshold)
```
    Truncate the supplied CharSequence.
    If the length of the CharSequence is greater than the threshold, this method returns a subsequence of the CharSequence (up to the threshold) appended with the suffix " (truncated)...". Otherwise, this method returns charSequence.toString().
    
    Parameters:
    
    charSequence - the CharSequence to truncate
    
    threshold - the maximum length after which to truncate; must be a positive number
    
    Returns:
    
    a truncated string, or a string representation of the original CharSequence if its length does not exceed the threshold
    
    Since:
    
    5.3.27

Class StringUtils

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

StringUtils

Method Detail

isEmpty

hasLength

hasLength

hasText

hasText

containsWhitespace

containsWhitespace

trimWhitespace

trimAllWhitespace

trimAllWhitespace

trimLeadingWhitespace

trimTrailingWhitespace

trimLeadingCharacter

trimTrailingCharacter

matchesCharacter

startsWithIgnoreCase

endsWithIgnoreCase

substringMatch

countOccurrencesOf

replace

delete

deleteAny

quote

quoteIfString

unqualify

unqualify

capitalize

uncapitalize

getFilename

getFilenameExtension

stripFilenameExtension

applyRelativePath

cleanPath

pathEquals

uriDecode

parseLocale

parseLocaleString

toLanguageTag

parseTimeZoneString

toStringArray

toStringArray

addStringToArray

concatenateStringArrays

mergeStringArrays

sortStringArray

trimArrayElements

removeDuplicateStrings

split

splitArrayElementsIntoProperties

splitArrayElementsIntoProperties

tokenizeToStringArray

tokenizeToStringArray

delimitedListToStringArray

delimitedListToStringArray

commaDelimitedListToStringArray

commaDelimitedListToSet

collectionToDelimitedString

collectionToDelimitedString

collectionToCommaDelimitedString

arrayToDelimitedString

arrayToCommaDelimitedString

truncate

truncate