GTrans

Free Google Translation API library build by Java 8.

GTrans uses the Google Translate Ajax API to make calls to such methods as detect and translate.

Features

Fast, reliable and simple
Auto language detection & Support Hundreds of languages
Single / Bulk translation
Connection pooling (Apache HttpClient)

Future

Proxy/Proxy Pool support

How to use

Basic Usage (Single translation)

Provide source & target language to enable translate, you can also use auto if you don't know type.

// get client api
GoogleTranslate googleTranslate = new GoogleTranslate();

// single words translation
String singleWords = "안녕하세요 세계";
List<String> result = googleTranslate.translate(singleWords, "auto", "en");
System.out.println(result.toString());

>>>[Hello world]

Advanced Usage (Bulk translation)

Use String List can translate a batch of strings with one HTTP Request.

// get client api
GoogleTranslate googleTranslate = new GoogleTranslate();

// bulk words translation
List<String> bulkWords = new LinkedList<String>();
bulkWords.add("使用しています");
bulkWords.add("Google翻译接口");

List<String> result = googleTranslate.translate(bulkWords, "auto", "en");
System.out.println(result.toString());

>>>[I'm using, Google translation interface]

Language Detect

Identify the language used in a given sentence or sentences.

// get client api
GoogleTranslate googleTranslate = new GoogleTranslate();
List<String> result;

String singleWords = "안녕하세요 세계";

List<String> bulkWords = new LinkedList<String>();
bulkWords.add("使用しています");
bulkWords.add("Google翻译接口");

// single detect
result = googleTranslate.detect(singleWords);
System.out.println(result.toString());

// bulk detect
result = googleTranslate.detect(bulkWords);
System.out.println(result.toString());

>>>[ko]
>>>[ja, zh-CN]

How it works

We found a way to generate such token with a special algorithm.

/**
 * calculate tk
 * @param source str to translate
 * @return token
 * @throws UnsupportedEncodingException source can't be encode to utf-8
 */
public String calculateTk(String source) throws UnsupportedEncodingException {
    byte[] sourceBytes = source.getBytes("UTF-8"); // encode utf-8

    BigInteger a = tkk.get(0);
    for (byte k : sourceBytes)
        // java byte range from -127~128, use '& 0xff' turn to range 0~256
        a = rl(a.add(new BigInteger(String.valueOf(k & 0xff))), "+-a^+6");
    a = rl(a, "+-3^+b+-f");

    a = a.xor(tkk.get(1));
    if (a.compareTo(new BigInteger("0")) < 0)
        a = (a.and(new BigInteger("2147483647"))).add(new BigInteger("2147483648"));
    a = a.remainder(new BigInteger("1000000")); // get mod

    return String.format("%s.%s", a, a.xor(tkk.get(0)));
}

private static BigInteger rl(BigInteger a, String b){
    for (int c = 0; c < b.length() - 2; c += 3){
        char d = b.charAt(c + 2);
        int e;
        if (d >= 'a')
            e = d - 87;
        else
            e = getNumericValue((int)d);

        BigInteger f;
        if (b.charAt(c + 1) == '+')
            f = a.shiftRight(e);
        else
            f = a.shiftLeft(e);

        if (b.charAt(c) == '+')
            a = a.add(f).and(new BigInteger("4294967295"));
        else
            a = a.xor(f);
    }
    return a;
}

The algorithm has multi-language version, like Python.

Note

DISCLAIMER: this is an unofficial library using the web API of translate.googleapis.com and also is not associated with Google.

The API has limitations. Read Google Service Items get more information.
If you want to use a stable API, use Google's official translate API instead.
If you visit too frequently, you may get HTTP 429/430 error or errors. It means your IP probably has been banned. The restriction will be lifted after 24 hours.

License

GTrans has already licensed under the MIT License.

Frank-ZYW/GTrans