java.lang.Object
- tech.tablesaw.util.StringUtils

```
public class StringUtils
extends Object
```
Operations on String that are null safe.
StringUtils handles null input Strings quietly. That is to say that a null input will return null. Where a boolean or int is being returned details vary by method.
A side effect of the null handling is that a NullPointerException should be considered a bug in StringUtils.
Methods in this class give sample code to explain their operation. The symbol * is used to indicate any input including null.
#ThreadSafe#

Since:

1.0

See Also:

String

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static String`	`abbreviate(String str, String abbrevMarker, int maxWidth)`	Abbreviates a String using ellipses.
`static String`	`capitalize(String str)`	Capitalizes a String changing the first character to title case as per `Character.toTitleCase(int)`.
`static boolean`	`isAllLowerCase(String cs)`	Checks if the CharSequence contains only lowercase characters.
`static boolean`	`isAllUpperCase(String cs)`	Checks if the CharSequence contains only uppercase characters.
`static boolean`	`isAlpha(String cs)`	Checks if the CharSequence contains only Unicode letters.
`static boolean`	`isAlphanumeric(String cs)`	Checks if the CharSequence contains only Unicode letters or digits.
`static boolean`	`isNumeric(String cs)`	Checks if the CharSequence contains only Unicode digits.
`static String`	`join(Object[] array, char separator)`	Joins the elements of the provided array into a single String containing the provided list of elements.
`static int`	`length(CharSequence cs)`	Gets a CharSequence length or `0` if the CharSequence is `null`.
`static String`	`removeZeroDecimal(String str)`	Removes all trailing zero decimals from the given String, assuming all decimals are zero and any zero decimals actually exist.
`static String`	`repeat(String str, int repeat)`	Repeat a String `repeat` times to form a new String.
`static String[]`	`splitByCharacterTypeCamelCase(String str)`	Splits a String by Character type as returned by `java.lang.Character.getType(char)`.

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

- Method Detail
  - splitByCharacterTypeCamelCase
```
public static String[] splitByCharacterTypeCamelCase(String str)
```
    Splits a String by Character type as returned by java.lang.Character.getType(char). Groups of contiguous characters of the same type are returned as complete tokens, with the following exception: if camelCase is true, the character of type Character.UPPERCASE_LETTER, if any, immediately preceding a token of type Character.LOWERCASE_LETTER will belong to the following token rather than to the preceding, if any, Character.UPPERCASE_LETTER token.
    
    Parameters:
    
    str - the String to split, may be null
    
    Returns:
    
    an array of parsed Strings, null if null String input
    
    Since:
    
    2.4
  - join
```
public static String join(Object[] array,
                          char separator)
```
    Joins the elements of the provided array into a single String containing the provided list of elements.
    No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings.
    StringUtils.join(null, *) = null StringUtils.join([], *) = "" StringUtils.join([null], *) = "" StringUtils.join(["a", "b", "c"], ';') = "a;b;c" StringUtils.join(["a", "b", "c"], null) = "abc" StringUtils.join([null, "", "a"], ';') = ";;a"
    Parameters:
    
    array - the array of values to join together, may be null
    
    separator - the separator character to use
    
    Returns:
    
    the joined String, null if null array input
    
    Since:
    
    2.0
  - repeat
```
public static String repeat(String str,
                            int repeat)
```
    Repeat a String repeat times to form a new String.
    StringUtils.repeat(null, 2) = null StringUtils.repeat("", 0) = "" StringUtils.repeat("", 2) = "" StringUtils.repeat("a", 3) = "aaa" StringUtils.repeat("ab", 2) = "abab" StringUtils.repeat("a", -2) = ""
    Parameters:
    
    str - the String to repeat, may be null
    
    repeat - number of times to repeat str, negative treated as zero
    
    Returns:
    
    a new String consisting of the original String repeated, null if null String input
  - length
```
public static int length(CharSequence cs)
```
    Gets a CharSequence length or 0 if the CharSequence is null.
    
    Parameters:
    
    cs - a CharSequence or null
    
    Returns:
    
    CharSequence length or 0 if the CharSequence is null.
    
    Since:
    
    2.4, 3.0 Changed signature from length(String) to length(CharSequence)
  - capitalize
```
public static String capitalize(String str)
```
    Capitalizes a String changing the first character to title case as per Character.toTitleCase(int). No other characters are changed.
    A null input String returns null.
    StringUtils.capitalize(null) = null StringUtils.capitalize("") = "" StringUtils.capitalize("cat") = "Cat" StringUtils.capitalize("cAt") = "CAt" StringUtils.capitalize("'cat'") = "'cat'"
    Parameters:
    
    str - the String to capitalize, may be null
    
    Returns:
    
    the capitalized String, null if null String input
    
    Since:
    
    2.0
  - isAlpha
```
public static boolean isAlpha(String cs)
```
    Checks if the CharSequence contains only Unicode letters.
    null will return false. An empty CharSequence (length()=0) will return false.
    StringUtils.isAlpha(null) = false StringUtils.isAlpha("") = false StringUtils.isAlpha(" ") = false StringUtils.isAlpha("abc") = true StringUtils.isAlpha("ab2c") = false StringUtils.isAlpha("ab-c") = false
    Parameters:
    
    cs - the CharSequence to check, may be null
    
    Returns:
    
    true if only contains letters, and is non-null
    
    Since:
    
    3.0 Changed signature from isAlpha(String) to isAlpha(CharSequence), 3.0 Changed "" to return false and not true
  - isAlphanumeric
```
public static boolean isAlphanumeric(String cs)
```
    Checks if the CharSequence contains only Unicode letters or digits.
    null will return false. An empty CharSequence (length()=0) will return false.
    StringUtils.isAlphanumeric(null) = false StringUtils.isAlphanumeric("") = false StringUtils.isAlphanumeric(" ") = false StringUtils.isAlphanumeric("abc") = true StringUtils.isAlphanumeric("ab c") = false StringUtils.isAlphanumeric("ab2c") = true StringUtils.isAlphanumeric("ab-c") = false
    Parameters:
    
    cs - the CharSequence to check, may be null
    
    Returns:
    
    true if only contains letters or digits, and is non-null
    
    Since:
    
    3.0 Changed signature from isAlphanumeric(String) to isAlphanumeric(CharSequence), 3.0 Changed "" to return false and not true
  - isNumeric
```
public static boolean isNumeric(String cs)
```
    Checks if the CharSequence contains only Unicode digits. A decimal point is not a Unicode digit and returns false.
    null will return false. An empty CharSequence (length()=0) will return false.
    Note that the method does not allow for a leading sign, either positive or negative. Also, if a String passes the numeric test, it may still generate a NumberFormatException when parsed by Integer.parseInt or Long.parseLong, e.g. if the value is outside the range for int or long respectively.
    StringUtils.isNumeric(null) = false StringUtils.isNumeric("") = false StringUtils.isNumeric(" ") = false StringUtils.isNumeric("123") = true StringUtils.isNumeric("१२३") = true StringUtils.isNumeric("12 3") = false StringUtils.isNumeric("ab2c") = false StringUtils.isNumeric("12-3") = false StringUtils.isNumeric("12.3") = false StringUtils.isNumeric("-123") = false StringUtils.isNumeric("+123") = false
    Parameters:
    
    cs - the CharSequence to check, may be null
    
    Returns:
    
    true if only contains digits, and is non-null
    
    Since:
    
    3.0 Changed signature from isNumeric(String) to isNumeric(CharSequence), 3.0 Changed "" to return false and not true
  - isAllLowerCase
```
public static boolean isAllLowerCase(String cs)
```
    Checks if the CharSequence contains only lowercase characters.
    null will return false. An empty CharSequence (length()=0) will return false.
    StringUtils.isAllLowerCase(null) = false StringUtils.isAllLowerCase("") = false StringUtils.isAllLowerCase(" ") = false StringUtils.isAllLowerCase("abc") = true StringUtils.isAllLowerCase("abC") = false StringUtils.isAllLowerCase("ab c") = false StringUtils.isAllLowerCase("ab1c") = false StringUtils.isAllLowerCase("ab/c") = false
    Parameters:
    
    cs - the CharSequence to check, may be null
    
    Returns:
    
    true if only contains lowercase characters, and is non-null
    
    Since:
    
    2.5, 3.0 Changed signature from isAllLowerCase(String) to isAllLowerCase(CharSequence)
  - isAllUpperCase
```
public static boolean isAllUpperCase(String cs)
```
    Checks if the CharSequence contains only uppercase characters.
    null will return false. An empty String (length()=0) will return false.
    StringUtils.isAllUpperCase(null) = false StringUtils.isAllUpperCase("") = false StringUtils.isAllUpperCase(" ") = false StringUtils.isAllUpperCase("ABC") = true StringUtils.isAllUpperCase("aBC") = false StringUtils.isAllUpperCase("A C") = false StringUtils.isAllUpperCase("A1C") = false StringUtils.isAllUpperCase("A/C") = false
    Parameters:
    
    cs - the CharSequence to check, may be null
    
    Returns:
    
    true if only contains uppercase characters, and is non-null
    
    Since:
    
    2.5, 3.0 Changed signature from isAllUpperCase(String) to isAllUpperCase(CharSequence)
  - removeZeroDecimal
```
public static String removeZeroDecimal(String str)
```
    Removes all trailing zero decimals from the given String, assuming all decimals are zero and any zero decimals actually exist.
    A null input String returns null.
    
    Parameters:
    
    str - the String to handle, may be null
    
    Returns:
    
    string without trailing zero decimals
  - abbreviate
```
public static String abbreviate(String str,
                                String abbrevMarker,
                                int maxWidth)
```
    Abbreviates a String using ellipses. This will turn "Now is the time for all good men" into "Now is the time for..."
    Specifically:
    
    If the number of characters in str is less than or equal to maxWidth, return str.
    Else abbreviate it to (substring(str, 0, max-3) + "...").
    If maxWidth is less than 4, throw an IllegalArgumentException.
    In no case will it return a String of length greater than maxWidth.
    
    StringUtils.abbreviate(null, *) = null StringUtils.abbreviate("", 4) = "" StringUtils.abbreviate("abcdefg", 6) = "abc..." StringUtils.abbreviate("abcdefg", 7) = "abcdefg" StringUtils.abbreviate("abcdefg", 8) = "abcdefg" StringUtils.abbreviate("abcdefg", 4) = "a..." StringUtils.abbreviate("abcdefg", 3) = IllegalArgumentException
    Parameters:
    
    str - the String to check, may be null
    
    abbrevMarker - the String indicate abbreviation
    
    maxWidth - maximum length of result String, must be at least 4
    
    Returns:
    
    abbreviated String, null if null String input
    
    Throws:
    
    IllegalArgumentException - if the width is too small
    
    Since:
    
    2.0

Class StringUtils

Method Summary

Methods inherited from class java.lang.Object

Method Detail

splitByCharacterTypeCamelCase

join

repeat

length

capitalize

isAlpha

isAlphanumeric

isNumeric

isAllLowerCase

isAllUpperCase

removeZeroDecimal

abbreviate