使用httpclient实现免费的google翻译api

import java.io.inputstream;
import java.net.urlencoder;
import java.text.messageformat;

import org.apache.commons.io.ioutils;

import org.bb.util.net.http.httpclientutil;
import org.jsoup.jsoup;
import org.jsoup.nodes.document;
import org.jsoup.nodes.element;

/**
 * translateutil
 *
 * <pre>翻譯工具
 * ps: 透過google translate
 * </pre>
 *
 * @author catty
 * @version 1.0, created on 2011/9/2
 */
public class translateutil {

 protected static final string url_template = "http://translate.google.com/?langpair={0}&text={1}";
 protected static final string id_resultbox = "result_box";
 protected static final string encoding = "utf-8";

 protected static final string auto = "auto"; // google自動判斷來源語系
 protected static final string taiwan = "zh-tw"; // 繁中
 protected static final string china = "zh-cn"; // 簡中
 protected static final string english = "en"; // 英
 protected static final string japan = "ja"; // 日

 /**
  * <pre>google翻譯
  * ps: 交由google自動判斷來源語系
  * </pre>
  *
  * @param text
  * @param target_lang 目標語系
  * @return
  * @throws exception
  */
 public static string translate(final string text, final string target_lang) throws exception {
  return translate(text, auto, target_lang);
 }

 /**
  * <pre>google翻譯</pre>
  *
  * @param text
  * @param src_lang 來源語系
  * @param target_lang 目標語系
  * @return
  * @throws exception
  */
 public static string translate(final string text, final string src_lang, final string target_lang)
   throws exception {
  inputstream is = null;
  document doc = null;
  element ele = null;
  try {
   // create url string
   string url = messageformat.format(url_template,
     urlencoder.encode(src_lang + "|" + target_lang, encoding),
     urlencoder.encode(text, encoding));

   // connect & download html
   is = httpclientutil.downloadasstream(url);

   // parse html by jsoup
   doc = jsoup.parse(is, encoding, "");
   ele = doc.getelementbyid(id_resultbox);
   string result = ele.text();
   return result;

  } finally {
   ioutils.closequietly(is);
   is = null;
   doc = null;
   ele = null;
  }
 }

 /**
  * <pre>google翻譯: 簡中-->繁中</pre>
  *
  * @param text
  * @return
  * @throws exception
  */
 public static string cn2tw(final string text) throws exception {
  return translate(text, china, taiwan);
 }

 /**
  * <pre>google翻譯: 繁中-->簡中</pre>
  *
  * @param text
  * @return
  * @throws exception
  */
 public static string tw2cn(final string text) throws exception {
  return translate(text, taiwan, china);
 }

 /**
  * <pre>google翻譯: 英文-->繁中</pre>
  *
  * @param text
  * @return
  * @throws exception
  */
 public static string en2tw(final string text) throws exception {
  return translate(text, english, taiwan);
 }

 /**
  * <pre>google翻譯: 繁中-->英文</pre>
  *
  * @param text
  * @return
  * @throws exception
  */
 public static string tw2en(final string text) throws exception {
  return translate(text, taiwan, english);
 }

 /**
  * <pre>google翻譯: 日文-->繁中</pre>
  *
  * @param text
  * @return
  * @throws exception
  */
 public static string jp2tw(final string text) throws exception {
  return translate(text, japan, taiwan);
 }

 /**
  * <pre>google翻譯: 繁中-->日</pre>
  *
  * @param text
  * @return
  * @throws exception
  */
 public static string tw2jp(final string text) throws exception {
  return translate(text, taiwan, japan);
 }
}

import java.io.bufferedinputstream;
import java.io.file;
import java.io.fileoutputstream;
import java.io.inputstream;
import java.util.map;

import org.apache.commons.io.ioutils;
import org.apache.commons.logging.log;
import org.apache.commons.logging.logfactory;
import org.apache.http.httpentity;
import org.apache.http.httpresponse;
import org.apache.http.client.httpclient;
import org.apache.http.client.methods.httpget;
import org.apache.http.client.methods.httppost;
import org.apache.http.client.methods.httprequestbase;
import org.apache.http.conn.scheme.plainsocketfactory;
import org.apache.http.conn.scheme.scheme;
import org.apache.http.conn.scheme.schemeregistry;
import org.apache.http.conn.ssl.sslsocketfactory;
import org.apache.http.entity.bufferedhttpentity;
import org.apache.http.impl.client.defaulthttpclient;
import org.apache.http.impl.conn.tsccm.threadsafeclientconnmanager;
import org.apache.http.params.basichttpparams;

/**
 * postutil.java
 *
 * @author catty
 * @version 1.0, created on 2008/2/20
 */
public class httpclientutil {

 protected static log log = logfactory.getlog(httpclientutil.class);
 protected static httpclient httpclient = null;
 protected static int maxtotal = 200;
 protected static int maxperroute = 20;
 protected static string useragent = "mozilla/5.0 (windows nt 6.1; wow64) applewebkit/535.7 (khtml, like gecko) chrome/16.0.912.77 safari/535.7";

 static {
  if (httpclient == null) {
   // ~~~~~~~~~~~~~~~~~~~~
   // create httpclient
   // ~~~~~~~~~~~~~~~~~~~~
   schemeregistry reg = new schemeregistry();
   reg.register(new scheme("http", 80, plainsocketfactory.getsocketfactory()));
   reg.register(new scheme("https", 443, sslsocketfactory.getsocketfactory()));
   threadsafeclientconnmanager cm = new threadsafeclientconnmanager(reg);
   cm.setmaxtotal(maxtotal);
   cm.setdefaultmaxperroute(maxperroute);
   httpclient = new defaulthttpclient(cm);
  }
 }

 /**
  * <pre>下載後回傳inputstream</pre>
  *
  * @param url
  * @return
  * @throws exception
  */
 public static inputstream downloadasstream(string url) throws exception {
  inputstream is = (inputstream) download(url, null, null, false);
  return is;
 }

 /**
  * <pre>下載後儲存到file</pre>
  *
  * @param url
  * @param savefile
  * @throws exception
  */
 public static void download(string url, file savefile) throws exception {
  download(url, savefile, null, false);
 }

 /**
  * <pre>下載</pre>
  *
  * @param url
  * @param savefile
  * @param params
  * @param ispost
  * @return 如果savefile==null則回傳inputstream, 否則回傳savefile
  * @throws exception
  */
 public static object download(final string url, final file savefile, final map<string, string> params,
   final boolean ispost) throws exception {

  boolean savetofile = savefile != null;

  // check dir exist ??
  if (savetofile && savefile.getparentfile().exists() == false) {
   savefile.getparentfile().mkdirs();
  }

  exception err = null;
  httprequestbase request = null;
  httpresponse response = null;
  httpentity entity = null;
  fileoutputstream fos = null;
  object result = null;

  try {
   // create request
   if (ispost) {
    request = new httppost(url);
   } else {
    request = new httpget(url);
   }

   // add header & params
   addheaderandparams(request, params);

   // connect
   response = httpclient.execute(request);
   entity = response.getentity();
   entity = new bufferedhttpentity(entity);

   // get result
   if (savetofile) {// save to disk
    fos = new fileoutputstream(savefile);
    ioutils.copy(entity.getcontent(), fos);
    result = savefile;
   } else { // warp to inpustream
    result = new bufferedinputstream(entity.getcontent());
   }

  } catch (exception e) {
   err = e;
  } finally {

   // close
   ioutils.closequietly(fos);

   // clear
   request = null;
   response = null;
   entity = null;

   if (err != null) {
    throw err;
   }

   return result;
  }

 }

 protected static void addheaderandparams(final httprequestbase request, final map<string, string> params) {
  // add default header
  request.addheader("user-agent", useragent);

  // add params
  if (params != null) {

   // map --> httpparams
   basichttpparams myparams = new basichttpparams();
   for (string key : params.keyset()) {
    myparams.setparameter(key, params.get(key));
   }

   request.setparams(myparams);
  }
 }

 public static httpclient gethttpclient() {
  return httpclient;
 }

 public static void sethttpclient(httpclient httpclient) {
  httpclientutil.httpclient = httpclient;
 }

 public static int getmaxtotal() {
  return maxtotal;
 }

 public static void setmaxtotal(int maxtotal) {
  httpclientutil.maxtotal = maxtotal;
 }

 public static int getmaxperroute() {
  return maxperroute;
 }

 public static void setmaxperroute(int maxperroute) {
  httpclientutil.maxperroute = maxperroute;
 }

 public static string getuseragent() {
  return useragent;
 }

 public static void setuseragent(string useragent) {
  httpclientutil.useragent = useragent;
 }
}