Android 通过当前经纬度获得城市的实例代码

package com.yy;
import java.io.inputstreamreader;
import java.net.httpurlconnection;
import java.net.url;

import javax.xml.parsers.saxparser;
import javax.xml.parsers.saxparserfactory;

import org.xml.sax.attributes;
import org.xml.sax.inputsource;
import org.xml.sax.saxexception;
import org.xml.sax.xmlreader;
import org.xml.sax.helpers.defaulthandler;

import android.content.context;
import android.location.location;
import android.location.locationmanager;

public class getcity {
 /**
  * 借助google map 通过用户当前经纬度 获得用户当前城市
  */
 static final string google_maps_api_key = "abcdefg";

 private locationmanager locationmanager;
 private location currentlocation;
 private string city="全国";
 public getcity(context context) {
  this.locationmanager = (locationmanager) context
    .getsystemservice(context.location_service);
  //只是简单的获取城市 不需要实时更新 所以这里先注释
//  this.locationmanager.requestlocationupdates(
//    locationmanager.gps_provider,  1000, 0,
//    new locationlistener() {
//     public void onlocationchanged(location loc) {
//      //当坐标改变时触发此函数，如果provider传进相同的坐标，它就不会被触发
//      // save the latest location
//      currentlocation = loc;
//      // update the latitude & longitude textviews
//      system.out
//        .println("getcity()"
//          + (loc.getlatitude() + " " + loc
//            .getlongitude()));
//     }
//
//     public void onproviderdisabled(string arg0) {
//      system.out.println(".onproviderdisabled(关闭)"+arg0);
//     }
//
//     public void onproviderenabled(string arg0) {
//      system.out.println(".onproviderenabled(开启)"+arg0);
//     }
//
//     public void onstatuschanged(string arg0, int arg1,
//       bundle arg2) {
//      system.out.println(".onstatuschanged(provider的转态在可用、" +
//        "暂时不可用和无服务三个状态直接切换时触发此函数)"+
//        arg0+" "+arg1+" "+arg2);
//     }
//    });
  currentlocation = locationmanager.getlastknownlocation(locationmanager.gps_provider);

  if (currentlocation == null)
   currentlocation = locationmanager
     .getlastknownlocation(locationmanager.network_provider);
 }
 /**
  * 开始解析
  */
 public void start() {
  if(currentlocation!=null){
   new thread(){
    public void run(){
     string temp=reversegeocode(currentlocation);
     if(temp!=null&&temp.length()>=2)
      city=temp;
    }
   }.start();
  }else{
   system.out.println("getcity.start()未获得location");
  }
 }

 /**
  * 获得城市
  * @return
  */
 public string getcity(){
  return city;
 }

 /**
  * 通过google  map api 解析出城市
  * @param loc
  * @return
  */
 public string reversegeocode(location loc) {
  // http://maps.google.com/maps/geo?q=40.714224,-73.961452&output=json&oe=utf8&sensor=true_or_false&key=your_api_key
  string localityname = "";
  httpurlconnection connection = null;
  url serveraddress = null;

  try {
   // build the url using the latitude & longitude you want to lookup
   // note: i chose xml return format here but you can choose something
   // else
   serveraddress = new url("http://maps.google.com/maps/geo?q="
     + double.tostring(loc.getlatitude()) + ","
     + double.tostring(loc.getlongitude())
     + "&output=xml&oe=utf8&sensor=true&key="
     + google_maps_api_key);
   // set up out communications stuff
   connection = null;

   // set up the initial connection
   connection = (httpurlconnection) serveraddress.openconnection();
   connection.setrequestmethod("get");
   connection.setdooutput(true);
   connection.setreadtimeout(10000);

   connection.connect();

   try {
    inputstreamreader isr = new inputstreamreader(connection
      .getinputstream());
    inputsource source = new inputsource(isr);
    saxparserfactory factory = saxparserfactory.newinstance();
    saxparser parser = factory.newsaxparser();
    xmlreader xr = parser.getxmlreader();
    googlereversegeocodexmlhandler handler = new googlereversegeocodexmlhandler();

    xr.setcontenthandler(handler);
    xr.parse(source);

    localityname = handler.getlocalityname();
    system.out.println("getcity.reversegeocode()"+localityname);
   } catch (exception ex) {
    ex.printstacktrace();
   }
  } catch (exception ex) {
   ex.printstacktrace();
   system.out.println("getcity.reversegeocode()"+ex);
  }

  return localityname;
 }

 /**
  * the final piece of this puzzle is parsing the xml tha