Servlet使用外部API

/*
參考資料
http://bit.ly/2umBcG8
 */
/*
用Servlet POST 給API.AI請求與取得回應，正常版不亂碼
*/
package jt;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.entity.StringEntity;
import org.apache.http.util.EntityUtils;

public class AIConversationServlet extends HttpServlet {

    private String tokenId = "";//API.AI那邊的TokenId

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");

        PrintWriter out = response.getWriter();
        String userInput = new String(request.getParameter("userInput").getBytes("UTF-8"));
        String url = "https://api.api.ai/v1/query?v=20150910";
        url = this.stringParser(url);
        String urlParameters = "{\"query\": [\"" + userInput + "\"],\"lang\": \"zh-cn\",\"sessionId\": \"1234567890\"}";
        HttpClient httpClient = HttpClientBuilder.create().build();
        HttpPost post = new HttpPost(url);
        post.setHeader("Content-type", "application/json;charset=utf-8");
        post.setHeader("Authorization", tokenId);
        post.setEntity(new StringEntity(urlParameters, "UTF-8"));
        HttpResponse theResponse = httpClient.execute(post);
        HttpEntity entity = theResponse.getEntity();
        String responseString = EntityUtils.toString(entity, "UTF-8");
        out.write(responseString);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
    }

    public String stringParser(String url) throws IOException {
        String url2 = new String();
        for (int j = 0; j < url.length(); j++) {
            if (url.substring(j, j + 1).matches("[\\u4e00-\\u9fa5]+")) {
                try {
                    url2 = url2 + URLEncoder.encode(url.substring(j, j + 1), "UTF-8");
                } catch (UnsupportedEncodingException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            } else {
                url2 = url2 + url.substring(j, j + 1).toString();
            }
        }

        return url2;
    }
    public static String getBody(HttpServletRequest request) throws IOException {

        String body = null;
        StringBuilder stringBuilder = new StringBuilder();
        BufferedReader bufferedReader = null;

        try {
            InputStream inputStream = request.getInputStream();
            if (inputStream != null) {
                bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                char[] charBuffer = new char[128];
                int bytesRead = -1;
                while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
                    stringBuilder.append(charBuffer, 0, bytesRead);
                }
            } else {
                stringBuilder.append("");
            }
        } catch (IOException ex) {
            throw ex;
        } finally {
            if (bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException ex) {
                    throw ex;
                }
            }
        }

        body = stringBuilder.toString();
        return body;
    }
}

需匯入apache的套件