gTTS4j (Google Text to Speech): Java version of an interface to Google's Text to Speech API.

import com.dragonbean.cloud.gTTS4j;

gTTS4j gtts = new gTTS4j();
gtts.init(text, "en", true, false);

• text - String - Text to be spoken.
• lang - String - ISO 639-1 language code (supported by the Google Text to Speech API) to speak in.
• slow - Boolean - Speak slowly. Default False (Note: only two speeds are provided by the API).

InputStream is = gtts.exec();

InputStream is = null;
String text = "Surprise!";
gTTS4j gtts = new gTTS4j();
try {
    gtts.init(text, "en", true, false);
    is = gtts.exec();
} catch (Exception e) {
    e.printStackTrace();
} finally {
    if (is != null) is.close();
}

• 'af' : 'Afrikaans'
• 'sq' : 'Albanian'
• 'ar' : 'Arabic'
• 'hy' : 'Armenian'
• 'bn' : 'Bengali'
• 'ca' : 'Catalan'
• 'zh' : 'Chinese'
• 'zh-cn' : 'Chinese (Mandarin/China)'
• 'zh-tw' : 'Chinese (Mandarin/Taiwan)'
• 'zh-yue' : 'Chinese (Cantonese)'
• 'hr' : 'Croatian'
• 'cs' : 'Czech'
• 'da' : 'Danish'
• 'nl' : 'Dutch'
• 'en' : 'English'
• 'en-au' : 'English (Australia)'
• 'en-uk' : 'English (United Kingdom)'
• 'en-us' : 'English (United States)'
• 'eo' : 'Esperanto'
• 'fi' : 'Finnish'
• 'fr' : 'French'
• 'de' : 'German'
• 'el' : 'Greek'
• 'hi' : 'Hindi'
• 'hu' : 'Hungarian'
• 'is' : 'Icelandic'
• 'id' : 'Indonesian'
• 'it' : 'Italian'
• 'ja' : 'Japanese'
• 'km' : 'Khmer (Cambodian)'
• 'ko' : 'Korean'
• 'la' : 'Latin'
• 'lv' : 'Latvian'
• 'mk' : 'Macedonian'
• 'no' : 'Norwegian'
• 'pl' : 'Polish'
• 'pt' : 'Portuguese'
• 'ro' : 'Romanian'
• 'ru' : 'Russian'
• 'sr' : 'Serbian'
• 'si' : 'Sinhala'
• 'sk' : 'Slovak'
• 'es' : 'Spanish'
• 'es-es' : 'Spanish (Spain)'
• 'es-us' : 'Spanish (United States)'
• 'sw' : 'Swahili'
• 'sv' : 'Swedish'
• 'ta' : 'Tamil'
• 'th' : 'Thai'
• 'tr' : 'Turkish'
• 'uk' : 'Ukrainian'
• 'vi' : 'Vietnamese'
• 'cy' : 'Welsh'

1. Fork yp2211/gTTS4j on GitHub and clone it locally
2. Make sure you write tests for new features or modify the existing ones if necessary
3. Open a new Pull Request from your feature branch to the master branch.
4. Thank you!