原文：http://www.open-open.com/code/view/1421032487812

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
 
/** 
* 获取经纬度
* 
* @author jueyue 返回格式：Map<String,Object> map map.put("status", 
* reader.nextString());//状态 map.put("result", list);//查询结果 
* list<map<String,String>> 
* 密钥:f247cdb592eb43ebac6ccd27f796e2d2 
*/ 
public class GetLatAndLngByBaidu { 
     
    /** 
    * @param addr 
    * 查询的地址 
    * @return 
    * @throws IOException 
    */ 
    public Object[] getCoordinate(String addr) throws IOException { 
        String lng = null;//经度
        String lat = null;//纬度
        String address = null; 
        try { 
            address = java.net.URLEncoder.encode(addr, "UTF-8"); 
        }catch (UnsupportedEncodingException e1) { 
            e1.printStackTrace(); 
        } 
        String key = "f247cdb592eb43ebac6ccd27f796e2d2"; 
        String url = String .format("http://api.map.baidu.com/geocoder?address=%s&output=json&key=%s", address, key); 
        URL myURL = null; 
        URLConnection httpsConn = null; 
        try { 
            myURL = new URL(url); 
        } catch (MalformedURLException e) { 
            e.printStackTrace(); 
        } 
        InputStreamReader insr = null;
        BufferedReader br = null;
        try { 
            httpsConn = (URLConnection) myURL.openConnection();// 不使用代理 
            if (httpsConn != null) { 
                insr = new InputStreamReader( httpsConn.getInputStream(), "UTF-8"); 
                br = new BufferedReader(insr); 
                String data = http://www.mamicode.com/null; ":")+1, data.indexOf(","));//经度
                        count++;
                    }else if(count==6){
                        lat = data.substring(data.indexOf(":")+1);//纬度
                        count++;
                    }else{
                        count++;
                    }
                } 
            } 
        } catch (IOException e) { 
            e.printStackTrace(); 
        } finally {
            if(insr!=null){
                insr.close();
            }
            if(br!=null){
                br.close();
            }
        }
        return new Object[]{lng,lat}; 
    } 
 
 
    public static void main(String[] args) throws IOException {
        GetLatAndLngByBaidu getLatAndLngByBaidu = new GetLatAndLngByBaidu();
        Object[] o = getLatAndLngByBaidu.getCoordinate("成都市天府四街");
        System.out.println(o[0]);//经度
        System.out.println(o[1]);//纬度
    }
 
}

输出结果：104.04701

                 30.548397

调用以下路径根据经纬度获取地址，返回数据为JSON格式，

http://api.map.baidu.com/geocoder/v2/?ak=pmCgmADsAsD9rEXkqWNcTzjd&location=30.548397,104.04701&output=json&pois=1

返回结果：

{"status":0,"result":{"location":{"lng":104.04701001273,"lat":30.548396923974},"formatted_address":"四川省成都市武侯区天府四街","business":"","addressComponent":{"city":"成都市","district":"武侯区","province":"四川省","street":"天府四街","street_number":""},"pois":[{"addr":"四川省成都市武侯区天府四街","cp":"NavInfo","distance":"144","name":"保利·心语花园","poiType":"地产小区","point":{"x":104.04823889466,"y":30.54874673449},"tel":"","uid":"881965b85a8d8a977369d348","zip":""},{"addr":"四川省成都市武侯区天府四街","cp":"NavInfo","distance":"629","name":"逸都国际","poiType":"地产小区","point":{"x":104.05247889667,"y":30.547152788724},"tel":"","uid":"e49f869c4f156be9c6effb6b","zip":""},{"addr":"四川省成都市武侯区剑南大道","cp":"NavInfo","distance":"881","name":"世豪广场","poiType":"地产小区","point":{"x":104.05252381195,"y":30.553318490823},"tel":"","uid":"a2a7b0b167a0e1997adbd206","zip":""},{"addr":"四川省成都市武侯区德赛三街","cp":"NavInfo","distance":"989","name":"顾客停车场","poiType":"交通设施","point":{"x":104.04942465794,"y":30.555798655385},"tel":"","uid":"d135a6e15571911483a00cfe","zip":""}],"cityCode":75}}

Java根据百度API获得经纬度，然后根据经纬度在获得城市信息