如何在android中提取和显示字段

How to extract and display field in android

本文关键字：显示字段提取 android 更新时间：2023-09-26

请在下方查找Main.java代码

public class Main extends Activity implements OnClickListener {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    findViewById(R.id.my_button).setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
    Button b = (Button)findViewById(R.id.my_button);
    b.setClickable(false);
    new LongRunningGetIO().execute();
}
private class LongRunningGetIO extends AsyncTask <Void, Void, String> {
    protected String getASCIIContentFromEntity(HttpEntity entity) throws IllegalStateException, IOException {
       InputStream in = entity.getContent();
         StringBuffer out = new StringBuffer();
         int n = 1;
         while (n>0) {
             byte[] b = new byte[4096];
             n =  in.read(b);
             if (n>0) out.append(new String(b, 0, n));
         }
         return out.toString();
    }
    @Override
    protected String doInBackground(Void... params) {
         HttpClient httpClient = new DefaultHttpClient();
         HttpContext localContext = new BasicHttpContext();
         HttpGet httpGet = new HttpGet("http://191.166.1.88:2000");
         String text = null;
         try {
               HttpResponse response = httpClient.execute(httpGet, localContext);
               HttpEntity entity = response.getEntity();
               text = getASCIIContentFromEntity(entity);
         } catch (Exception e) {
             return e.getLocalizedMessage();
         }
         return text;
    }   
    protected void onPostExecute(String results) {
        if (results!=null) {
            EditText et = (EditText)findViewById(R.id.my_edit);
            et.setText(results);
        }
        Button b = (Button)findViewById(R.id.my_button);
        b.setClickable(true);
      }
     }
     }

我从REST API获取JSON数据，如下所示

 {"Tm":{"Time": "Mon Nov 20 12:45:59 IST 2015"},"Name":
 {"Host": "u1", "IP": "190.166.169.137"},"Speed":{"cpu":   
   2494.259033203125}}

如何只提取主机的"u1"的Nama，并在android中的文本框中显示。我是新手，请帮助

将您的doInBackground更改为这一点，也使doInBackbackground的返回类型从String返回到JSONObject。

 try {
            URL url = new URL("http://191.166.1.88:2000");
            HttpURLConnection connection = (HttpURLConnection)url.openConnection();
            connection.connect();
            System.out.println(connection.getResponseMessage());
            responseCode = connection.getResponseCode();
            if(responseCode == HttpURLConnection.HTTP_OK) {
                InputStream inputStream = connection.getInputStream();
                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
                String responseData = "", data="";
                while ((data = reader.readLine()) != null){
                    responseData += data + "'n";
                }
                jsonResponse = new JSONObject(responseData);
            } else {
                //Not Success
            }
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return jsonResponse;
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return jsonResponse;
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return jsonResponse;
        }
        return jsonResponse;

以及对这个的onPostExecute

 @Override
    protected void onPostExecute(JSONObject result) {
        if(result != null) {
             JSONObject name =result.getJSONObject("Name"); 
             String host = name.getString("Host");
        }
    }