Commons-lang-stringutils

Operations on that is String null safe.

Isempty/isblank -Checks if a string is empty (judging if the string is empty)

Trim/strip -removes leading and trailing whitespace (control characters before and after deletion, white space characters)

Equals -compares-strings null-safe (determines if strings are equal)

StartsWith -check if a String starts with a prefix null-safe

EndsWith -check if a String ends with a suffix null-safe

indexof/lastindexof/contains -Null-safe index-of Checks

indexofany/lastindexofany/indexofanybut/lastindexofanybut -index-of any of a set of Strings

Containsonly/containsnone/containsany -does String contains only/none/any of these characters

substring/left/right/mid -Null-safe Substring extractions

substringbefore/substringafter/substringbetween -substring extraction relative to other strings ( Gets the substring relative to the delimiter position)

Split/join -Splits a string to an array of substrings and vice versa (split, concatenation string)

remove/delete -Removes part of a String

Replace/overlay -Searches a string and replaces one string with another

chomp/chop -Removes the last part of a String

appendifmissing -Appends a suffix to the end of the string if not present (if the character does not end with the specified suffix, append the suffix back after the string)

prependifmissing -prepends a prefix to the start of the string if not present (if the character does not start with the specified prefix, the prefix is returned before the string)

leftpad/rightpad/center/Repeat -Pads a String

uppercase/lowercase/swapcase/capitalize/uncapitalize -Changes the case of a String (changing the casing of characters)

countmatches -counts the number of occurrences of one String in another

isalpha/isnumeric/iswhitespace/isasciiprintable -checks the characters in a String

defaultstring -protects against a null input String (prevent null)

Reverse/reversedelimited -Reverses a string (inverse string)

abbreviate -abbreviates a string using ellipsis

difference -compares Strings and reports on their differences

levenshteindistance -The number of changes needed to change one String into another

More:javadoc

Commons-lang-stringutils