Is there a method for String conversion to Title Case?

Question

Apache Commons StringUtils.capitalize() or Commons Text WordUtils.capitalize()

e.g: WordUtils.capitalize("i am FINE") = "I Am FINE" from WordUtils doc

There are no capitalize() or titleCase() methods in Java's String class. You have two choices:

• using commons lang string utils.

 StringUtils.capitalize(null)  = null
 StringUtils.capitalize("")    = ""
 StringUtils.capitalize("cat") = "Cat"
 StringUtils.capitalize("cAt") = "CAt"
 StringUtils.capitalize("'cat'") = "'cat'"

• write (yet another) static helper method toTitleCase()

Sample implementation

public static String toTitleCase(String input) {
    StringBuilder titleCase = new StringBuilder(input.length());
    boolean nextTitleCase = true;

    for (char c : input.toCharArray()) {
        if (Character.isSpaceChar(c)) {
            nextTitleCase = true;
        } else if (nextTitleCase) {
            c = Character.toTitleCase(c);
            nextTitleCase = false;
        }

        titleCase.append(c);
    }

    return titleCase.toString();
}

Testcase

    System.out.println(toTitleCase("string"));
    System.out.println(toTitleCase("another string"));
    System.out.println(toTitleCase("YET ANOTHER STRING"));

outputs:

String
Another String
YET ANOTHER STRING

If I may submit my take on the solution...

The following method is based on the one that dfa posted. It makes the following major change (which is suited to the solution I needed at the time): it forces all characters in the input string into lower case unless it is immediately preceded by an "actionable delimiter" in which case the character is coerced into upper case.

A major limitation of my routine is that it makes the assumption that "title case" is uniformly defined for all locales and is represented by the same case conventions I have used and so it is less useful than dfa's code in that respect.

public static String toDisplayCase(String s) {

    final String ACTIONABLE_DELIMITERS = " '-/"; // these cause the character following
                                                 // to be capitalized
    
    StringBuilder sb = new StringBuilder();
    boolean capNext = true;

    for (char c : s.toCharArray()) {
        c = (capNext)
                ? Character.toUpperCase(c)
                : Character.toLowerCase(c);
        sb.append(c);
        capNext = (ACTIONABLE_DELIMITERS.indexOf((int) c) >= 0); // explicit cast not needed
    }
    return sb.toString();
}

TEST VALUES

a string

maRTin o'maLLEY

john wilkes-booth

YET ANOTHER STRING

OUTPUTS

A String

Martin O'Malley

John Wilkes-Booth

Yet Another String

Use WordUtils.capitalizeFully() from Apache Commons.

WordUtils.capitalizeFully(null)        = null
WordUtils.capitalizeFully("")          = ""
WordUtils.capitalizeFully("i am FINE") = "I Am Fine"

You can use apache commons langs like this :

WordUtils.capitalizeFully("this is a text to be capitalize")

you can find the java doc here : WordUtils.capitalizeFully java doc

and if you want to remove the spaces in between the worlds you can use :

StringUtils.remove(WordUtils.capitalizeFully("this is a text to be capitalize")," ")

you can find the java doc for String StringUtils.remove java doc

i hope this help.

If you want the correct answer according to the latest Unicode standard, you should use icu4j.

UCharacter.toTitleCase(Locale.US, "hello world", null, 0);

Note that this is locale sensitive.

Api Documentation

Implementation

Here's another take based on @dfa's and @scottb's answers that handles any non-letter/digit characters:

public final class TitleCase {

    public static String toTitleCase(String input) {

        StringBuilder titleCase = new StringBuilder(input.length());
        boolean nextTitleCase = true;

        for (char c : input.toLowerCase().toCharArray()) {
            if (!Character.isLetterOrDigit(c)) {
                nextTitleCase = true;
            } else if (nextTitleCase) {
                c = Character.toTitleCase(c);
                nextTitleCase = false;
            }
            titleCase.append(c);
        }

        return titleCase.toString();
    }

}

Given input:

MARY ÄNN O’CONNEŽ-ŠUSLIK

the output is

Mary Änn O’Connež-Šuslik