Package com.privatejgoodies.common.base

Class Strings

java.lang.Object
com.privatejgoodies.common.base.Strings
public class Strings extends Object
Provides frequently used static null-safe String testing methods .
Author:
Karsten Lentzsch

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    ELLIPSIS_STRING
    The correct ellipsis string.
    static final String
    NO_ELLIPSIS_STRING
    A string with three dots that should is often meant to be the ellipsis string "…" or character '…'.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    Strings()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static String
    abbreviateCenter(String str, int maxLength)
    Abbreviates the given string if it exceeds the given maximum length by replacing its center part with an ellipsis ('…').
    static boolean
    isBlank(String str)
    Checks if the given string is whitespace, empty ("") or null.
    static boolean
    isEmpty(String str)
    Checks if the given string is empty ("") or null.
    static boolean
    isNotBlank(String str)
    Checks if the given string is not empty (""), not null and not whitespace only.
    static boolean
    isNotEmpty(String str)
    Checks if the given string is not empty ("") and not null.
    static boolean
    isTrimmed(String str)
    Checks if the given string is null, empty (""), or the first and last characters are not whitespace.
    static boolean
    startsWithIgnoreCase(String str, String prefix)
    Checks if str starts with the given prefix ignoring cases.

    Methods inherited from class java.lang.Object

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

  • Field Details

  • Constructor Details

    • Strings

      protected Strings()

  • Method Details

    • isBlank

      public static boolean isBlank(String str)
      Checks if the given string is whitespace, empty ("") or null. 
       Strings.isBlank(null)    == true
 Strings.isBlank("")      == true
 Strings.isBlank(" ")     == true
 Strings.isBlank(" abc")  == false
 Strings.isBlank("abc ")  == false
 Strings.isBlank(" abc ") == false
      Parameters:
      str - the string to check, may be null
      Returns:
      true if the string is whitespace, empty or null
      See Also:

    • isNotBlank

      public static boolean isNotBlank(String str)
      Checks if the given string is not empty (""), not null and not whitespace only. 
       Strings.isNotBlank(null)    == false
 Strings.isNotBlank("")      == false
 Strings.isNotBlank(" ")     == false
 Strings.isNotBlank(" abc")  == true
 Strings.isNotBlank("abc ")  == true
 Strings.isNotBlank(" abc ") == true
      Parameters:
      str - the string to check, may be null
      Returns:
      true if the string is not empty and not null and not whitespace only
      See Also:

    • isEmpty

      public static boolean isEmpty(String str)
      Checks if the given string is empty ("") or null. 
       Strings.isEmpty(null)  == true
 Strings.isEmpty("")    == true
 Strings.isEmpty(" ")   == false
 Strings.isEmpty("Hi ") == false
      Parameters:
      str - the string to check, may be null
      Returns:
      true if the string is empty or null
      See Also:

    • isNotEmpty

      public static boolean isNotEmpty(String str)
      Checks if the given string is not empty ("") and not null. 
       Strings.isNotEmpty(null)  == false
 Strings.isNotEmpty("")    == false
 Strings.isNotEmpty(" ")   == true
 Strings.isNotEmpty("Hi")  == true
 Strings.isNotEmpty("Hi ") == true
      Parameters:
      str - the string to check, may be null
      Returns:
      true if the string is not empty and not null
      See Also:

    • isTrimmed

      public static boolean isTrimmed(String str)
      Checks if the given string is null, empty (""), or the first and last characters are not whitespace. 
       Strings.isTrimmed(null)  == true
 Strings.isTrimmed("")    == true
 Strings.isTrimmed(" ")   == false
 Strings.isTrimmed("Hi")  == true
 Strings.isTrimmed("Hi ") == false
 Strings.isTrimmed(" Hi") == false
      Parameters:
      str - the string to check, may be null
      Returns:
      true if the string is null, empty, or the first and last characters are not whitespace.
      Since:
      1.3

    • startsWithIgnoreCase

      public static boolean startsWithIgnoreCase(String str, String prefix)
      Checks if str starts with the given prefix ignoring cases. null is handled safely; if both arguments are null, true is returned, false otherwise. 
       Strings.startsWithIgnoreCase(null, null)      == true
 Strings.startsWithIgnoreCase("a", null)       == false
 Strings.startsWithIgnoreCase(null, "a")       == false
 Strings.startsWithIgnoreCase("",  "")         == true
 Strings.startsWithIgnoreCase(" ", "")         == true
 Strings.startsWithIgnoreCase("John", "J")     == true
 Strings.startsWithIgnoreCase("John", "Jo")    == true
 Strings.startsWithIgnoreCase("John", "Joh")   == true
 Strings.startsWithIgnoreCase("John", "joh")   == true
 Strings.startsWithIgnoreCase("john", "Joh")   == true
 Strings.startsWithIgnoreCase("john", "joh")   == true
 Strings.startsWithIgnoreCase("John", "John")  == true
 Strings.startsWithIgnoreCase("John", "john")  == true
 Strings.startsWithIgnoreCase("John", "Jonny") == false
      Parameters:
      str - the test string to check, may be null
      prefix - the prefix to check for, may be null
      Returns:
      true, if the string starts with the prefix, ignoring cases, false otherwise
      See Also:

    • abbreviateCenter

      public static String abbreviateCenter(String str, int maxLength)
      Abbreviates the given string if it exceeds the given maximum length by replacing its center part with an ellipsis ('…'). If the string is null or shorter than the limit, it is returned as is.

       Strings.abbreviateCenter(null,      3) == null
 Strings.abbreviateCenter("",        3) == ""
 Strings.abbreviateCenter(" ",       3) == " "
 Strings.abbreviateCenter("a",       3) == "a"
 Strings.abbreviateCenter("ab",      3) == "ab"
 Strings.abbreviateCenter("abc",     3) == "abc"
 Strings.abbreviateCenter("abcd",    3) == "a…d"
 Strings.abbreviateCenter("abcde",   3) == "a…e"
 Strings.abbreviateCenter("abcde",   4) == "ab…e"
 Strings.abbreviateCenter("abcdef",  4) == "ab…f"
 Strings.abbreviateCenter("abcdefg", 5) == "ab…fg"
      Parameters:
      str - the source string
      maxLength - the maximum length of the result string
      Returns:
      str if its length is less than or equal to maxLength, an abbreviated string with length maxLength where the center is replaced by an ellipsis