根据百度API获得经纬度，然后根据经纬度在获得城市信息

package com.pb.baiduapi;

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 = null; 
				int count = 1;
				while((data= br.readLine())!=null){ 
					if(count==5){
						lng = (String)data.subSequence(data.indexOf(":")+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}}