(JAVA)基于JFinal框架调用百度地图公交路线规划API

这次用JAVA代码来复现一次调用。基于JFinal框架。（上次PHP调用看上一篇文章）

一、在控制器创建BaidumapController

package Controller;

import Calculation.SnCal;
import com.jfinal.core.Controller;
import com.jfinal.kit.HttpKit;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.LinkedHashMap;
import java.util.Map;

public class BaidumapController extends Controller {
    public void index() throws UnsupportedEncodingException {
    String sk = "yoursk";
    String uri = "/direction/v2/transit?";

    String ak = "yourak";

    String origin = "22.693621,113.817503";
    String destination = "22.579575,114.143696";
    String origin_uid = "桥头-地铁站";
    String destination_uid = "太安-地铁站";
    String departure_time = "10:00-12:00";
    String tactics_incity = "5";
    int timestamp = (int) (System.currentTimeMillis() / 1000);

    SnCal snCal = new SnCal();

/* 计算sn跟参数对出现顺序有关，get请求请使用LinkedHashMap保存<key,value>，该方法根据key的插入顺序排序；post请使用TreeMap保存<key,value>，该方法会自动将key按照字母a-z顺序排序。所以get请求可自定义参数顺序（sn参数必须在最后）发送请求，但是post请求必须按照字母a-z顺序填充body（sn参数必须在最后）。以get请求为例：http://api.map.baidu.com/geocoder/v2/?address=百度大厦&output=json&ak=yourak，paramsMap中先放入address，再放output，然后放ak，放入顺序必须跟get请求中对应参数的出现顺序保持一致。 */

    Map paramsMap = new LinkedHashMap<String, String>();
    paramsMap.put("origin", origin);
    paramsMap.put("destination", destination);
    paramsMap.put("origin_uid", origin_uid);
    paramsMap.put("destination_uid", destination_uid);
    paramsMap.put("departure_time", departure_time);
    paramsMap.put("tactics_incity", tactics_incity);
    paramsMap.put("ak", ak);
    paramsMap.put("timestamp", Integer.toString(timestamp));


    // 调用下面的toQueryString方法，对LinkedHashMap内所有value作utf8编码，拼接返回结果
    String paramsStr = snCal.toQueryString(paramsMap);

     // 对paramsStr前面拼接上uri，后面直接拼接yoursk
     String wholeStr = new String(uri + paramsStr + sk);

     // 对上面wholeStr再作utf8编码
     String tempStr = URLEncoder.encode(wholeStr, "UTF-8");

     // 调用下面的MD5方法得到最后的sn签名
     String sn= snCal.MD5(tempStr);

     // 用返回的sn拼接进URL
    String url = "http://api.map.baidu.com/direction/v2/transit?origin="+URLEncoder.encode(origin)+"&destination="+URLEncoder.encode(destination)+"&origin_uid="+URLEncoder.encode(origin_uid)+"&destination_uid="+URLEncoder.encode(destination_uid)+"&departure_time="+URLEncoder.encode(departure_time)+"&tactics_incity="+tactics_incity+"&ak="+ak+"&sn="+sn+"&timestamp="+timestamp;

    // 模拟http get请求
    String json = HttpKit.get(url);

    // 返回json
    renderJson(json);
    }
}

二、在公共函数包中创建SnCal类

package Calculation;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Map;
import java.util.Map.Entry;

//java版计算signature签名
public class SnCal {
     // 对Map内所有value作utf8编码，拼接返回结果
     public String toQueryString(Map<?, ?> data) throws UnsupportedEncodingException 
     {
           StringBuffer queryString = new StringBuffer();
           for (Entry<?, ?> pair : data.entrySet()) {
                 queryString.append(pair.getKey() + "=");
                 queryString.append(URLEncoder.encode((String) pair.getValue(), "UTF-8") + "&");
            }
           if (queryString.length() > 0) {
                 queryString.deleteCharAt(queryString.length() - 1);
           }
           return queryString.toString();
      }


      // 来自stackoverflow的MD5计算方法，调用了MessageDigest库函数，并把byte数组结果转换成16进制
     public String MD5(String md5) {
          try {
              java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
              byte[] array = md.digest(md5.getBytes());
              StringBuffer sb = new StringBuffer();
              for (int i = 0; i < array.length; ++i) {
                   sb.append(Integer.toHexString((array[i] & 0xFF) | 0x100).substring(1, 3));
              }
              return sb.toString();
         } catch (java.security.NoSuchAlgorithmException e) {

         }
         return null;
       }
}