如何parsingAndroid中的JSON

我在哪里可以find关于如何parsingAndroid中的JSON提要的分步说明？ 我只是一个想学习的Android初学者。

Answer 1

Android有你需要parsingjson内置的所有工具。 示例如下，不需要GSON或类似的东西。

获取您的JSON：

DefaultHttpClient httpclient = new DefaultHttpClient(new BasicHttpParams()); HttpPost httppost = new HttpPost(http://someJSONUrl/jsonWebService); // Depends on your web service httppost.setHeader("Content-type", "application/json"); InputStream inputStream = null; String result = null; try { HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); inputStream = entity.getContent(); // json is UTF-8 by default BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"), 8); StringBuilder sb = new StringBuilder(); String line = null; while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } result = sb.toString(); } catch (Exception e) { // Oops } finally { try{if(inputStream != null)inputStream.close();}catch(Exception squish){} } 

现在你有你的JSON，那么是什么？

创build一个JSONObject ：

 JSONObject jObject = new JSONObject(result); 

得到一个特定的string

 String aJsonString = jObject.getString("STRINGNAME"); 

得到一个特定的布尔值

 boolean aJsonBoolean = jObject.getBoolean("BOOLEANNAME"); 

得到一个特定的整数

 int aJsonInteger = jObject.getInt("INTEGERNAME"); 

得到一个特定的长

 long aJsonLong = jObject.getBoolean("LONGNAME"); 

获得一个特定的双

 double aJsonDouble = jObject.getDouble("DOUBLENAME"); 

获取特定的JSONArray ：

 JSONArray jArray = jObject.getJSONArray("ARRAYNAME"); 

从数组中获取项目

 for (int i=0; i < jArray.length(); i++) { try { JSONObject oneObject = jArray.getJSONObject(i); // Pulling items from the array String oneObjectsItem = oneObject.getString("STRINGNAMEinTHEarray"); String oneObjectsItem2 = oneObject.getString("anotherSTRINGNAMEINtheARRAY"); } catch (JSONException e) { // Oops } } 

Answer 2

1. 编写JSONparsing器类

    public class JSONParser { static InputStream is = null; static JSONObject jObj = null; static String json = ""; // constructor public JSONParser() {} public JSONObject getJSONFromUrl(String url) { // Making HTTP request try { // defaultHttpClient DefaultHttpClient httpClient = new DefaultHttpClient(); HttpPost httpPost = new HttpPost(url); HttpResponse httpResponse = httpClient.execute(httpPost); HttpEntity httpEntity = httpResponse.getEntity(); is = httpEntity.getContent(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } try { BufferedReader reader = new BufferedReader(new InputStreamReader( is, "iso-8859-1"), 8); StringBuilder sb = new StringBuilder(); String line = null; while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } is.close(); json = sb.toString(); } catch (Exception e) { Log.e("Buffer Error", "Error converting result " + e.toString()); } // try parse the string to a JSON object try { jObj = new JSONObject(json); } catch (JSONException e) { Log.e("JSON Parser", "Error parsing data " + e.toString()); } // return JSON String return jObj; } } 

2. parsingJSON数据一旦你创build了parsing器类，接下来就是要知道如何使用这个类。 下面我解释如何使用parsing器类来parsingjson（在这个例子中）。

2.1。 将所有这些节点名称存储在variables中：在联系人json中，我们有诸如姓名，电子邮件，地址，性别和电话号码之类的项目。 所以首先是将所有这些节点名称存储在variables中。 打开您的主要活动类，并声明将所有节点名称存储在静态variables中。

 // url to make request private static String url = "http://api.9android.net/contacts"; // JSON Node names private static final String TAG_CONTACTS = "contacts"; private static final String TAG_ID = "id"; private static final String TAG_NAME = "name"; private static final String TAG_EMAIL = "email"; private static final String TAG_ADDRESS = "address"; private static final String TAG_GENDER = "gender"; private static final String TAG_PHONE = "phone"; private static final String TAG_PHONE_MOBILE = "mobile"; private static final String TAG_PHONE_HOME = "home"; private static final String TAG_PHONE_OFFICE = "office"; // contacts JSONArray JSONArray contacts = null; 

2.2。 使用parsing器类来获取JSONObject并循环遍历每个json项目。 下面我创build一个JSONParser类的实例，并使用循环，我循环通过每个JSON项目，并最终将每个JSON数据存储在variables中。

 // Creating JSON Parser instance JSONParser jParser = new JSONParser(); // getting JSON string from URL JSONObject json = jParser.getJSONFromUrl(url); try { // Getting Array of Contacts contacts = json.getJSONArray(TAG_CONTACTS); // looping through All Contacts for(int i = 0; i < contacts.length(); i++){ JSONObject c = contacts.getJSONObject(i); // Storing each json item in variable String id = c.getString(TAG_ID); String name = c.getString(TAG_NAME); String email = c.getString(TAG_EMAIL); String address = c.getString(TAG_ADDRESS); String gender = c.getString(TAG_GENDER); // Phone number is agin JSON Object JSONObject phone = c.getJSONObject(TAG_PHONE); String mobile = phone.getString(TAG_PHONE_MOBILE); String home = phone.getString(TAG_PHONE_HOME); String office = phone.getString(TAG_PHONE_OFFICE); } } catch (JSONException e) { e.printStackTrace(); } 

Answer 3

我已经为你编写了一个简单的例子，并注明了源代码。 这个例子展示了如何抓取实时json和parsing到一个JSONObject中来提取细节：

 try{ // Create a new HTTP Client DefaultHttpClient defaultClient = new DefaultHttpClient(); // Setup the get request HttpGet httpGetRequest = new HttpGet("http://example.json"); // Execute the request in the client HttpResponse httpResponse = defaultClient.execute(httpGetRequest); // Grab the response BufferedReader reader = new BufferedReader(new InputStreamReader(httpResponse.getEntity().getContent(), "UTF-8")); String json = reader.readLine(); // Instantiate a JSON object from the request response JSONObject jsonObject = new JSONObject(json); } catch(Exception e){ // In your production code handle any errors and catch the individual exceptions e.printStackTrace(); } 

一旦你有了JSONObject，就可以参考SDK了解如何提取你需要的数据。

Answer 4

尝试按照这个教程http://www.androidhive.info/2012/01/android-json-parsing-tutorial/希望这将帮助你开始与JSONParsing