在服务器与客户端之间通信,json数据是一种常用格式,本文主要在服务器端构建数据,在客户端接收显示,并且在listview上显示出来
服务器端的构建
简单的javabean与返回结果函数与插入函数略过
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {response.setContentType("text/html");response.setCharacterEncoding("UTF-8");PrintWriter out = response.getWriter();List<MyShop> shops = JsonService.getListShop();StringBuffer sb = new StringBuffer();sb.append('[');for (MyShop shop : shops) {sb.append('{').append("\"name\":").append("\""+shop.getName()+"\"").append(","); sb.append("\"detail\":").append("\""+shop.getDetail()+"\"").append(",");sb.append("\"distance\":").append("\""+shop.getDistance()+"\"").append(",");sb.append("\"address\":").append("\""+shop.getAddress()+"\"").append(",");sb.append("\"popularity\":").append(shop.getPopularity());sb.append('}').append(",");}sb.deleteCharAt(sb.length() - 1);sb.append(']');out.write(new String(sb));out.flush();out.close();}
在浏览器中直接输入访问http://localhost:8080/AppServer/JsonServlet
可得
可以在服务器端直接查看json数据
客户端接收与解析json数据
public class JsonParse {/*** 解析Json数据** @param urlPath* @return mlists* @throws Exception*/public static List<MyShop> getListShop(String urlPath) throws Exception {List<MyShop> mlists = new ArrayList<MyShop>();byte[] data = readParse(urlPath);JSONArray array = new JSONArray(new String(data));for (int i = 0; i < array.length(); i++) {JSONObject item = array.getJSONObject(i);String name = item.getString("name");String detail = item.getString("detail");String distance = item.getString("distance");String popularity = item.getString("popularity");String address = item.getString("address");mlists.add(new MyShop(name, detail, distance,address,popularity));}return mlists;}/*** 从指定的url中获取字节数组** @param urlPath* @return 字节数组* @throws Exception*/public static byte[] readParse(String urlPath) throws Exception {ByteArrayOutputStream outStream = new ByteArrayOutputStream();byte[] data = new byte[1024];int len = 0;URL url = new URL(urlPath);HttpURLConnection conn = (HttpURLConnection) url.openConnection();InputStream inStream = conn.getInputStream();while ((len = inStream.read(data)) != -1) {outStream.write(data, 0, len);}inStream.close();return outStream.toByteArray();}}
在activity中开启子线程来接收服务器数据
new Thread(new Runnable() {private String tag;@Overridepublic void run() {// TODO Auto-generated method stub//获得新闻集合List<MyShop> shopList = null;try {shopList = JsonParse.getListShop("http://192.168.247.1:8080/AppServer/JsonServlet");} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}Log.i(tag, "在RUN中LIST长度为"+shopList.size());Message msg=new Message();if(shopList!=null){msg.what=SUCCESS;msg.obj=shopList;}else{msg.what=FAILED;}handler.sendMessage(msg);Log.i(tag, "***********T长度为"+shopList.size());}}).start();
消息处理器
//消息处理器private Handler handler=new Handler(){/*** 接收消息*/@Overridepublic void handleMessage(Message msg) {// TODO Auto-generated method stubString tag = null;switch (msg.what) {case SUCCESS: //访问成功,有数据//绑定数据Log.i(tag,"%%%%%%%%%%到达了消息处理器");myshoplist=(List<MyShop>) msg.obj;Log.i(tag, "handleMessage中数据newInfoList长度为"+myshoplist.size());NearAdapter adapter=new NearAdapter();Log.i(tag, "有没有到达ADAPTER"+adapter.getCount());showList.setAdapter(adapter);break;case FAILED: //访问失败Toast.makeText(ChooseMer.this, "当前网络崩溃了", 0).show();break;default:break;}}};
配置适配器
public class NearAdapter extends BaseAdapter {@Overridepublic int getCount() {// TODO Auto-generated method stubreturn myshoplist.size();}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn null;}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn 0;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {if (convertView == null) {LayoutInflater inflater = LayoutInflater.from(ChooseMer.this);convertView = inflater.inflate(R.layout.nearby_list_item, null);init(convertView,position);}return convertView;}public void init(View convertView,int position) {hold.name = (TextView) convertView.findViewById(R.id.nearby_item_name);MyShop shop=myshoplist.get(position);hold.name.setText(shop.getName());hold.local = (TextView) convertView.findViewById(R.id.nearby_item_local);hold.local.setText(shop.getDetail());hold.dis1 = (TextView) convertView.findViewById(R.id.nearby_item_dis1);hold.dis1.setText(shop.getDistance());hold.dis2 = (TextView) convertView.findViewById(R.id.nearby_item_dis2);hold.dis2.setText(shop.getAddress());hold.dis3 = (TextView) convertView.findViewById(R.id.nearby_item_dis3);hold.dis3.setText(shop.getPopularity());}}