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;
@Override
public 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 block
e.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
*/
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
String 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 {
@Override
public int getCount() {
// TODO Auto-generated method stub
return myshoplist.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public 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());
}
}