Explore Java 21’s New Emoji Detection APIs

Java 21 adds six new static methods to java.lang.Character for detecting Emoji characters.

public static boolean isEmoji(int codePoint) { return CharacterData.of(codePoint).isEmoji(codePoint); }
public static boolean isEmojiPresentation(int codePoint) { return CharacterData.of(codePoint).isEmojiPresentation(codePoint); }
public static boolean isEmojiModifier(int codePoint) { return CharacterData.of(codePoint).isEmojiModifier(codePoint); }
public static boolean isEmojiModifierBase(int codePoint) { return CharacterData.of(codePoint).isEmojiModifierBase(codePoint); }
public static boolean isEmojiComponent(int codePoint) { return CharacterData.of(codePoint).isEmojiComponent(codePoint); }
public static boolean isExtendedPictographic(int codePoint) { return CharacterData.of(codePoint).isExtendedPictographic(codePoint); }

Each method receives a Unicode code point and returns a boolean indicating whether the character matches the specific Emoji property.

Example: using isEmoji to check if a string contains any Emoji.

@Test
void testEmoji() {
    String message = "欢迎来到 www.didispace.com ❤️，要不要来杯 ☕️ ？";
    if (message.codePoints().anyMatch(Character::isEmoji)) {
        System.out.println("Message包含表情");
    }
}

Additional examples show how to determine if an Emoji can be modified or has been modified using isEmojiModifier and isEmojiModifierBase.

@Test
void testEmoji2() {
    String welcomeMsg = "欢迎来到 www.didispace.com ❤️，要不要来杯 ☕️ ？";
    OptionalInt emojiOptional = welcomeMsg.codePoints().filter(Character::isEmoji).findFirst();
    if (emojiOptional.isPresent()) {
        int emojiCodePoint = emojiOptional.getAsInt();
        if (Character.isEmojiModifierBase(emojiCodePoint)) {
            System.out.println("Emoji can be modified");
            if (Character.isEmojiModifier(emojiCodePoint))
                System.out.println("Emoji is modified");
            else
                System.out.println("Emoji has not been modified");
        } else {
            System.out.println("Emoji cannot be modified");
        }
    } else {
        System.out.println("No emoji present");
    }
}

The new methods can also be used via regular expressions, for example:

String welcomeMsg = "欢迎来到 www.didispace.com ❤️，要不要来杯 ☕️ ？";
Matcher matcher = Pattern.compile("\\p{IsEmoji}").matcher(welcomeMsg);
if (matcher.find()) {
    System.out.println("Message contains an emoji!");
}
matcher = Pattern.compile("\\p{IsEmoji_Modifier_Base}").matcher(welcomeMsg);
if (matcher.find()) {
    System.out.println("Message contains an emoji modifier base!");
}