Android 开发工具类 25_getJSON

获取 JSON 数据并解析

 import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;

 import org.json.JSONArray;
 import org.json.JSONObject;

 import com.wangjialin.internet.json.domain.News;
 import com.wangjialin.internet.json.utils.StreamTool;

 public class NewsService {

     /**
      * 获取最新视频资讯
      * @return
      * @throws Exception
      */
     public static List<News> getJSONLastNews() throws Exception{

         String path = "http://192.168.1.103:8080/ServerForJSON/NewsListServlet";
         HttpURLConnection conn = (HttpURLConnection) new URL(path).openConnection();
         conn.setConnectTimeout(5000);
         conn.setRequestMethod("GET");

         if(conn.getResponseCode() == 200){
             InputStream json = conn.getInputStream();
             return parseJSON(json);
         }
         return null;
     }

     private static List<News> parseJSON(InputStream jsonStream) throws Exception{

         List<News> list = new ArrayList<News>();
         byte[] data = StreamTool.read(jsonStream);
         String json = new String(data);
         JSONArray jsonArray = new JSONArray(json);

         for(int i = 0; i < jsonArray.length() ; i++){
             JSONObject jsonObject = jsonArray.getJSONObject(i);
             int id = jsonObject.getInt("id");
             String title = jsonObject.getString("title");
             int timelength = jsonObject.getInt("timelength");
             list.add(new News(id, title, timelength));
         }
         return list;
     }
 }

StreamTool

 import java.io.ByteArrayOutputStream;
 import java.io.InputStream;

 public class StreamTool {
     /**
      * 从流中读取数据
      * @param inStream
      * @return
      */
     public static byte[] read(InputStream inStream) throws Exception{

         ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
         byte[] buffer = new byte[1024];
         int len = 0;

         while((len = inStream.read(buffer)) != -1){
             outputStream.write(buffer, 0, len);
         }

         inStream.close();
         return outputStream.toByteArray();
     }
 }

显示

 public class MainActivity extends Activity {
     /** Called when the activity is first created. */
     List<News> newes;
     List<HashMap<String, Object>> data = null;;
     String length;

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         setContentView(R.layout.main);
         ListView listView = (ListView) this.findViewById(R.id.listView);

         length = this.getResources().getString(R.string.length);

         try{
             newes = NewsService.getJSONLastNews();
             data = new ArrayList<HashMap<String,Object>>();
             for(News news : newes){
                 HashMap<String, Object> item = new HashMap<String, Object>();
                 item.put("id", news.getId());
                 item.put("title", news.getTitle());
                 item.put("timelength", length + news.getTimelength());
                 data.add(item);
             }                

             SimpleAdapter adapter = new SimpleAdapter(this,
                     data, R.layout.item,
                     new String[]{"title", "timelength"},
                     new int[]{R.id.title, R.id.timelength}
             );
             listView.setAdapter(adapter);
         }catch(Exception e)
         {
             e.printStackTrace();
         };
     }
 }