谷歌翻译接口使用（android为例）

对于android来说，很多翻译接口要收费的。但是翻译还是有很多网页版的，因此爬虫便成为一种方式。谷歌翻译中国版不需要翻墙，谷歌翻译中有一个接口可以得到翻译后的json。

例子：
https://translate.google.cn/translate_a/single?client=gtx&sl=en&tl=zh&dt=t&q=Do%20not%20work%20overtime%20tonight

在浏览器打开会下载一个f.txt的文件，内容为：
[[[“今晚不要加班”,”Do not work overtime tonight”,null,null,3]],null,”en”]。
在android中使用流的方式接收，转化为json进行相应处理即可。

如果翻译很长比如：
https://translate.google.cn/translate_a/single?client=gtx&sl=en&tl=zh&dt=t&q=The%20world%27s%20first%20railless%20train%20is%20tested%20in%20Zhuzhou,%20Central%20China%27s%20Hunan%20province,%20on%20Oct%2023,%202017.%20The%2030-meter%20train%20has%20three%20carriages%20and%20is%20developed%20by%20CRRC%20Zhuzhou%20Locomotive%20Co%20Ltd.%20The%20train%20can%20move%20at%20a%20speed%20of%2070%20km/h%20and%20can%20carry%20up%20to%20500%20passengers.

返回内容会是这个样子的：
[[[“2017年10月23日，中国中部湖南省株洲市测试了世界上第一列无轨列车.30米长的列车有三个车厢，由中国中车株洲机车有限公司开发，列车时速可达70公里/”,”The world’s first railless train is tested in Zhuzhou, Central China’s Hunan province, on Oct 23, 2017. The 30-meter train has three carriages and is developed by CRRC Zhuzhou Locomotive Co Ltd. The train can move at a speed of 70 km/”,null,null,3],[“小时，可载500名乘客。”,”h and can carry up to 500 passengers.”,null,null,3]],null,”en”]
只要进行相应处理与拼接即可。

sl=en 为source language，可设置为auto。
tl=zh 为target language，设置为目标语言。
注意在android中使用HttpURLConnection的话，需要设置User-Agent如：HttpURLConnection.setRequestProperty(“User-Agent”, “Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36”);

支持的语言：
“auto”:””Automatic”,
“af”:”Afrikaans”,
“sq”:”Albanian”,
“ar”:”Arabic”,
“hy”:”Armenian”,
“az”:”Azerbaijani”,
“eu”:”Basque”,
“be”:”Belarusian”,
“bn”:”Bengali”,
“bs”:”Bosnian”,
“bg”:”Bulgarian”,
“ca”:”Catalan”,
“ceb”:”Cebuano”,
“ny”:”Chichewa”,
“zh-cn”:”Chinese Simplified”,
“zh-tw”:”Chinese Traditional”,
“co”:”Corsican”,
“hr”:”Croatian”,
“cs”:”Czech”,
“da”:”Danish”,
“nl”:”Dutch”,
“en”:”English”,
“eo”:”Esperanto”,
“et”:”Estonian”,
“tl”:”Filipino”,
“fi”:”Finnish”,
“fr”:”French”,
“fy”:”Frisian”,
“gl”:”Galician”,
“ka”:”Georgian”,
“de”:”German”,
“el”:”Greek”,
“gu”:”Gujarati”,
“ht”:”Haitian Creole”,
“ha”:”Hausa”,
“haw”:”Hawaiian”,
“iw”:”Hebrew”,
“hi”:”Hindi”,
“hmn”:”Hmong”,
“hu”:”Hungarian”,
“is”:”Icelandic”,
“ig”:”Igbo”,
“id”:”Indonesian”,
“ga”:”Irish”,
“it”:”Italian”,
“ja”:”Japanese”,
“jw”:”Javanese”,
“kn”:”Kannada”,
“kk”:”Kazakh”,
“km”:”Khmer”,
“ko”:”Korean”,
“ku”:”Kurdish (Kurmanji)”,
“ky”:”Kyrgyz”,
“lo”:”Lao”,
“la”:”Latin”,
“lv”:”Latvian”,
“lt”:”Lithuanian”,
“lb”:”Luxembourgish”,
“mk”:”Macedonian”,
“mg”:”Malagasy”,
“ms”:”Malay”,
“ml”:”Malayalam”,
“mt”:”Maltese”,
“mi”:”Maori”,
“mr”:”Marathi”,
“mn”:”Mongolian”,
“my”:”Myanmar (Burmese)”,
“ne”:”Nepali”,
“no”:”Norwegian”,
“ps”:”Pashto”,
“fa”:”Persian”,
“pl”:”Polish”,
“pt”:”Portuguese”,
“ma”:”Punjabi”,
“ro”:”Romanian”,
“ru”:”Russian”,
“sm”:”Samoan”,
“gd”:”Scots Gaelic”,
“sr”:”Serbian”,
“st”:”Sesotho”,
“sn”:”Shona”,
“sd”:”Sindhi”,
“si”:”Sinhala”,
“sk”:”Slovak”,
“sl”:”Slovenian”,
“so”:”Somali”,
“es”:”Spanish”,
“su”:”Sudanese”,
“sw”:”Swahili”,
“sv”:”Swedish”,
“tg”:”Tajik”,
“ta”:”Tamil”,
“te”:”Telugu”,
“th”:”Thai”,
“tr”:”Turkish”,
“uk”:”Ukrainian”,
“ur”:”Urdu”,
“uz”:”Uzbek”,
“vi”:”Vietnamese”,
“cy”:”Welsh”,
“xh”:”Xhosa”,
“yi”:”Yiddish”,
“yo”:”Yoruba”,
“zu”:”Zulu”

代码例子：

/** * 翻译回调 */public interface TranslateCallback{    public void onTranslateDone(String result);}

import java.io.ByteArrayOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import java.net.URLEncoder;import java.util.HashMap;import java.util.Map;import java.util.concurrent.Executors;import android.content.Context;import android.os.AsyncTask;import android.util.Log;public class TranslateUtil {    public static final String TRANSLATE_BASE_URL = "https://translate.google.cn/"; // 不需要翻墙即可使用//    public static final String TRANSLATE_SINGLE_URL = "https://translate.google.cn/translate_a/single?client=gtx&sl=en&tl=zh&dt=t&q=Do%20not%20work%20overtime%20tonight";    public static final String USER_AGENT = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36";    private static String LAN_AUTO = "auto";    /**     * 翻译，包含http请求，需要异步，返回""则为翻译失败     * @param sourceLan 源语言，如en，自动检测为auto     * @param targetLan 目标语言如zh     * @param content 翻译文本     * @return ""为翻译失败，其余成功     */    public void translate(Context context, String sourceLan, String targetLan, String content, TranslateCallback callback) {        TranslateTask task = new TranslateTask(context, sourceLan, targetLan, content, callback);        task.executeOnExecutor(Executors.newCachedThreadPool());    }    /**     * 使用异步任务来翻译，翻译完成后回调callback     */    class TranslateTask extends AsyncTask<Void, Void, String> {        String sourceLan;        String targetLan;        String content;        Context context;        TranslateCallback callback;        private LoadingDalog loadingDalog = null; // 这个请自己定义加载中对话框，或者干脆不使用        TranslateTask(Context context, String sourceLan, String targetLan, String content, TranslateCallback callback){            this.context = context;            this.content = content;            this.callback = callback;            this.sourceLan = sourceLan;            this.targetLan = targetLan;        }        @Override        protected String doInBackground(Void... params) {            String result = "";            if (content == null || content.equals("")) {                return result;            }            try {                String googleResult = "";                // 新建一个URL对象                URL url = new URL(getTranslateUrl(sourceLan, targetLan, content));                // 打开一个HttpURLConnection连接                HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();                // 设置连接主机超时时间                urlConn.setConnectTimeout(5 * 1000);                //设置从主机读取数据超时                urlConn.setReadTimeout(5 * 1000);                // 设置是否使用缓存  默认是true                urlConn.setUseCaches(false);                // 设置为Post请求                urlConn.setRequestMethod("GET");                //urlConn设置请求头信息                urlConn.setRequestProperty("User-Agent", USER_AGENT);                //设置请求中的媒体类型信息。//            urlConn.setRequestProperty("Content-Type", "application/json");                //设置客户端与服务连接类型//            urlConn.addRequestProperty("Connection", "Keep-Alive");                // 开始连接                urlConn.connect();                // 判断请求是否成功                int statusCode = urlConn.getResponseCode();                if (statusCode == 200) {                    // 获取返回的数据                    googleResult = streamToString(urlConn.getInputStream());                }                // 关闭连接                urlConn.disconnect();                // 处理返回结果，拼接                JSONArray jsonArray = new JSONArray(googleResult).getJSONArray(0);                for (int i = 0; i < jsonArray.length(); i++) {                    result += jsonArray.getJSONArray(i).getString(0);                }            } catch (Exception e) {//            result = "翻译失败";                e.printStackTrace();                result = "";            }            Log.d("TAG", "翻译结果：" + result);            return result;        }        @Override        protected void onPostExecute(String result) {            if (loadingDalog != null && loadingDalog.isShowing()) {                loadingDalog.cancel();            }            if (callback != null){                callback.onTranslateDone(result);            }            super.onPostExecute(result);        }        @Override        protected void onPreExecute() {            super.onPreExecute();            String str = context.getString(R.string.translating);            try {                loadingDalog = new LoadingDalog(context);// Dialog使用、初始化                loadingDalog.setMessage(str);                loadingDalog.show();            } catch (Exception e) {                e.printStackTrace();            }        }    }    /**     * 将输入流转换成字符串     *     * @param is 从网络获取的输入流     * @return 字符串     */    public static String streamToString(InputStream is) {        try {            ByteArrayOutputStream out = new ByteArrayOutputStream();            byte[] buffer = new byte[1024];            int len = 0;            while ((len = is.read(buffer)) != -1) {                out.write(buffer, 0, len);            }            out.close();            is.close();            byte[] byteArray = out.toByteArray();            return new String(byteArray);        } catch (Exception e) {            return null;        }    }    public void translate(Context context, String targetLan, String content, TranslateCallback callback) {        translate(context, LAN_AUTO, targetLan, content, callback);    }    private static String getTranslateUrl(String sourceLan, String targetLan, String content) {        try {            return TRANSLATE_BASE_URL + "translate_a/single?client=gtx&sl=" + sourceLan + "&tl=" + targetLan + "&dt=t&q=" + URLEncoder.encode(content, "UTF-8");        } catch (Exception e) {            return TRANSLATE_BASE_URL + "translate_a/single?client=gtx&sl=" + sourceLan + "&tl=" + targetLan + "&dt=t&q=" + content;        }}

// 使用TranslateCallback translateCallback = new TranslateCallback() {    @Override    public void onTranslateDone(String result) {        // result是翻译结果，在这里使用翻译结果，比如使用对话框显示翻译结果    }}new TranslateUtil().translate(activity, "auto", "en", "待翻译内容", translateCallback);