从HTTP响应中获取JSON对象
我想从一个Http获取响应中获得一个JSON对象：
这里是我现在的Http代码：
protected String doInBackground(String... params) { HttpClient client = new DefaultHttpClient(); HttpGet request = new HttpGet(params[0]); HttpResponse response; String result = null; try { response = client.execute(request); HttpEntity entity = response.getEntity(); if (entity != null) { // A Simple JSON Response Read InputStream instream = entity.getContent(); result = convertStreamToString(instream); // now you have the string representation of the HTML request System.out.println("RESPONSE: " + result); instream.close(); if (response.getStatusLine().getStatusCode() == 200) { netState.setLogginDone(true); } } // Headers org.apache.http.Header[] headers = response.getAllHeaders(); for (int i = 0; i < headers.length; i++) { System.out.println(headers[i]); } } catch (ClientProtocolException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } return result; }
这里是convertSteamToString函数：
private static String convertStreamToString(InputStream is) { BufferedReader reader = new BufferedReader(new InputStreamReader(is)); StringBuilder sb = new StringBuilder(); String line = null; try { while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } } catch (IOException e) { e.printStackTrace(); } finally { try { is.close(); } catch (IOException e) { e.printStackTrace(); } } return sb.toString(); }
现在我只是得到一个string对象。 我怎样才能得到一个JSON对象。
你得到的string只是JSON Object.toString（）。 这意味着你得到了JSON对象，但是以String格式。
如果你应该得到一个JSON对象，你可以把：
JSONObject myObject = new JSONObject(result);
这样做来获得JSON
String json = EntityUtils.toString(response.getEntity());
更多细节在这里： 从HttpResponse获取JSON
没有看看你的确切的JSON输出，很难给你一些工作代码。 本教程非常有用，但您可以使用以下内容：
JSONObject jsonObj = new JSONObject("yourJsonString");
然后你可以使用这个json对象来检索：
String value = jsonObj.getString("yourKey");
这不是你的问题的确切答案，但这可能会帮助你
public class JsonParser { private static DefaultHttpClient httpClient = ConnectionManager.getClient(); public static List<Club> getNearestClubs(double lat, double lon) { // YOUR URL GOES HERE String getUrl = Constants.BASE_URL + String.format("getClosestClubs?lat=%f&lon=%f", lat, lon); List<Club> ret = new ArrayList<Club>(); HttpResponse response = null; HttpGet getMethod = new HttpGet(getUrl); try { response = httpClient.execute(getMethod); // CONVERT RESPONSE TO STRING String result = EntityUtils.toString(response.getEntity()); // CONVERT RESPONSE STRING TO JSON ARRAY JSONArray ja = new JSONArray(result); // ITERATE THROUGH AND RETRIEVE CLUB FIELDS int n = ja.length(); for (int i = 0; i < n; i++) { // GET INDIVIDUAL JSON OBJECT FROM JSON ARRAY JSONObject jo = ja.getJSONObject(i); // RETRIEVE EACH JSON OBJECT'S FIELDS long id = jo.getLong("id"); String name = jo.getString("name"); String address = jo.getString("address"); String country = jo.getString("country"); String zip = jo.getString("zip"); double clat = jo.getDouble("lat"); double clon = jo.getDouble("lon"); String url = jo.getString("url"); String number = jo.getString("number"); // CONVERT DATA FIELDS TO CLUB OBJECT Club c = new Club(id, name, address, country, zip, clat, clon, url, number); ret.add(c); } } catch (Exception e) { e.printStackTrace(); } // RETURN LIST OF CLUBS return ret; } } Again, it's relatively straight forward, but the methods I'll make special note of are: JSONArray ja = new JSONArray(result); JSONObject jo = ja.getJSONObject(i); long id = jo.getLong("id"); String name = jo.getString("name"); double clat = jo.getDouble("lat");
你需要像下面这样使用JSONObject ：
String mJsonString = downloadFileFromInternet(urls[0]); JSONObject jObject = null; try { jObject = new JSONObject(mJsonString); } catch (JSONException e) { e.printStackTrace(); return false; }
…
private String downloadFileFromInternet(String url) { if(url == null /*|| url.isEmpty() == true*/) new IllegalArgumentException("url is empty/null"); StringBuilder sb = new StringBuilder(); InputStream inStream = null; try { url = urlEncode(url); URL link = new URL(url); inStream = link.openStream(); int i; int total = 0; byte[] buffer = new byte[8 * 1024]; while((i=inStream.read(buffer)) != -1) { if(total >= (1024 * 1024)) { return ""; } total += i; sb.append(new String(buffer,0,i)); } } catch(Exception e ) { e.printStackTrace(); return null; }catch(OutOfMemoryError e) { e.printStackTrace(); return null; } return sb.toString(); } private String urlEncode(String url) { if(url == null /*|| url.isEmpty() == true*/) return null; url = url.replace("[",""); url = url.replace("]",""); url = url.replaceAll(" ","%20"); return url; }
希望这可以帮助你..
有一个JSONObject构造函数将string转换为JSONObject：
http://developer.android.com/reference/org/json/JSONObject.html#JSONObject(java.lang.String）;
