android开发-hack news droid的解析

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1. package com.glebpopov.hackernews.net;
3. import java.io.BufferedReader;
4. import java.io.IOException;
5. import java.io.InputStream;
6. import java.io.InputStreamReader;
7. import java.util.ArrayList;
9. import org.apache.http.HttpEntity;
10. import org.apache.http.HttpResponse;
11. import org.apache.http.client.HttpClient;
12. import org.apache.http.client.methods.HttpGet;
13. import org.apache.http.impl.client.DefaultHttpClient;
14. import org.json.JSONArray;
15. import org.json.JSONException;
16. import org.json.JSONObject;
18. import com.glebpopov.hackernews.domain.CommentItem;
19. import com.glebpopov.hackernews.domain.NewsContainer;
20. import com.glebpopov.hackernews.domain.NewsItem;
22. import android.util.Log;
24. public class DataParser
25. {
26. private String dataUrl = null;
27. private String TAG = "DataParser";
29. public DataParser(String url)
30. {
31. dataUrl = url;
32. }
34. public String getUrl()
35. {
36. return dataUrl;
37. }
39. //returns HTTP code
40. public int submitData()
41. {
42. if (getUrl() == null || getUrl().length() == 0)
43. {
44. Log.e(TAG, "getJsonData: invalid URL");
45. return 500;
46. }
47. // Create the httpclient
48. HttpClient httpclient = new DefaultHttpClient();
50. // Prepare a request object
51. HttpGet httpget = new HttpGet(getUrl());
53. // Execute the request
54. HttpResponse response;
56. try
57. {
58. // Open the webpage.
59. response = httpclient.execute(httpget);
60. return response.getStatusLine().getStatusCode();
61. }
62. catch (IOException ex)
63. {
64. // thrown by line 80 - getContent();
65. // Connection was not established
66. Log.e(TAG, "getJsonData: Connection failed: " + ex.getMessage());
67. }
68. finally
69. {
71. }
72. return 500;
73. }
75. public NewsContainer getNews()
76. {
77. if (dataUrl == null || dataUrl.length() == 0)
78. {
79. Log.e(TAG, "getNews: invalid URL");
80. return null;
81. }
82. Log.d(TAG, "URL: " + dataUrl);
84. NewsContainer container = null;
85. JSONArray jsonData = getJsonData();
86. if (jsonData != null)
87. {
88. container = new NewsContainer();
89. ArrayList data = new ArrayList();
90. NewsItem item = null;
91. NewsItem moreLink = null;
92. //shouldn't return links to NEXT...links to next should be appended somewhere else
93. for (int i=0; i
94. {
95. try
96. {
97. if (jsonData.getJSONObject(i).getString("title") != null &&
98. jsonData.getJSONObject(i).getString("title").toLowerCase().equals("nextid")
99. )
100. {
101. moreLink = new NewsItem();
102. moreLink.setTitle(jsonData.getJSONObject(i).getString("title"));
103. moreLink.setUrl("http://hndroidapi.appspot.com" + jsonData.getJSONObject(i).getString("url"));
105. } else
106. {
107. int id = 0;
108. try
109. {
110. id = Integer.parseInt(jsonData.getJSONObject(i).getString("item_id"));
111. } catch (Exception ex) {}
113. item = new NewsItem();
114. item.setTitle(jsonData.getJSONObject(i).getString("title"));
115. item.setUrl(jsonData.getJSONObject(i).getString("url"));
116. item.setPostedDate(jsonData.getJSONObject(i).getString("time"));
117. item.setPoints(jsonData.getJSONObject(i).getString("score"));
118. item.setAuthor(jsonData.getJSONObject(i).getString("user"));
119. item.setComments(jsonData.getJSONObject(i).getString("comments"));
120. item.setId(id);
122. //add to container
123. data.add(item);
124. }
125. } catch (Exception ex)
126. {
127. Log.e(TAG, "getNews: exception while parsing JSON data: " + ex);
128. }
129. }
131. container.setNewsContainer(data);
132. container.setMoreNewsLink(moreLink);
133. }
135. if (container != null && container.getNewsContainer() != null)
136. {
137. Log.d(TAG, "getNews: returning " + container.getNewsContainer().size() + " elements");
138. } else
139. {
140. Log.w(TAG, "getNews: failed to retrieve news data");
141. }
142. return container;
143. }
145. public ArrayList getComments()
146. {
147. if (dataUrl == null || dataUrl.length() == 0)
148. {
149. Log.e(TAG, "getComments: invalid URL");
150. return null;
151. }
152. JSONArray jsonData = getJsonData();
153. ArrayList data = parseComments(jsonData, -1);
154. Log.d(TAG, "getComments: returning " + data.size() + " elements");
155. return data;
156. }
158. public ArrayList parseComments(JSONArray jsonData, int parentId)
159. {
160. //Log.d(TAG, "parseComments: ParentID=" + parentID);
162. ArrayList data = new ArrayList();
163. if (jsonData != null)
164. {
165. //Log.d(TAG, "parseComments: Container Count=" + jsonData.length());
166. CommentItem item = null;
167. for (int i=0; i
168. {
169. item = new CommentItem();
170. try
171. {
172. int id = -1;
173. try
174. {
175. id = Integer.parseInt(jsonData.getJSONObject(i).getString("id"));
176. } catch (Exception ex) {}
178. item.setId(id);
179. item.setParentId(parentId);
180. item.setComment(jsonData.getJSONObject(i).getString("comment"));
181. item.setReplyId(jsonData.getJSONObject(i).getString("reply_id"));
182. item.setPostedDate(jsonData.getJSONObject(i).getString("time"));
183. item.setAuthor(jsonData.getJSONObject(i).getString("username"));
184. if (jsonData.getJSONObject(i).getJSONArray("children") != null)
185. {
186. item.setChildren(parseComments(jsonData.getJSONObject(i).getJSONArray("children"), id));
187. }
189. } catch (Exception ex)
190. {
191. Log.e(TAG, "parseComments: exception while parsing JSON data: " + ex);
192. }
193. data.add(item);
194. }
195. }
196. return data;
197. }
199. public JSONArray getJsonData()
200. {
201. if (dataUrl == null || dataUrl.length() == 0)
202. {
203. Log.e(TAG, "getJsonData: invalid URL");
204. return null;
205. }
206. // Create the httpclient
207. HttpClient httpclient = new DefaultHttpClient();
209. // Prepare a request object
210. HttpGet httpget = new HttpGet(dataUrl);
212. // Execute the request
213. HttpResponse response;
215. try {
217. // return string
218. String returnString = null;
220. // Open the webpage.
221. response = httpclient.execute(httpget);
223. if(response.getStatusLine().getStatusCode() == 200){
224. // Connection was established. Get the content.
226. HttpEntity entity = response.getEntity();
227. // If the response does not enclose an entity, there is no need
228. // to worry about connection release
232. if (entity != null) {
233. // A Simple JSON Response Read
234. InputStream instream = entity.getContent();
236. returnString = convertStreamToString(instream);
238. //Log.d(TAG, "Return String: " + returnString);
240. // Load the requested page converted to a string into a JSONObject.
241. JSONObject myAwway = new JSONObject(returnString);
243. // Get the query value'
244. //String query = myAwway.getString("query");
246. // Make array of the suggestions
247. JSONArray recs = myAwway.getJSONArray("items");
248. if (recs != null)
249. {
250. Log.d(TAG, "getJsonData: Got JSON Data: " + recs.length());
251. } else
252. {
253. Log.w(TAG, "getJsonData: no data returned");
254. }
255. // Cose the stream.
256. instream.close();
257. return recs;
259. }
261. }
262. else {
263. // code here for a response othet than 200. A response 200 means the webpage was ok
264. // Other codes include 404 - not found, 301 - redirect etc...
265. // Display the response line.
266. Log.e(TAG, "getJsonData: Unable to load page. Status: " + response.getStatusLine());
267. }
268. }
269. catch (IOException ex) {
270. // thrown by line 80 - getContent();
271. // Connection was not established
272. Log.e(TAG, "getJsonData: Connection failed: " + ex.getMessage());
273. }
274. catch (JSONException ex){
275. // JSON errors
276. Log.e(TAG, "getJsonData: JSONException: " + ex.getMessage());
277. } finally
278. {
280. }
281. return null;
282. }
284. public String convertStreamToString(InputStream is) {
285. /*
286. * To convert the InputStream to String we use the BufferedReader.readLine()
287. * method. We iterate until the BufferedReader return null which means
288. * there's no more data to read. Each line will appended to a StringBuilder
289. * and returned as String.
290. */
291. BufferedReader reader = new BufferedReader(new InputStreamReader(is));
292. StringBuilder sb = new StringBuilder();
294. String line = null;
295. try {
296. while ((line = reader.readLine()) != null) {
297. sb.append(line + "\n");
298. }
299. } catch (IOException e) {
300. e.printStackTrace();
301. } finally {
302. try {
303. is.close();
304. } catch (IOException e) {
305. e.printStackTrace();
306. }
307. }
308. return sb.toString();
309. }
311. public NewsItem getLatestNews() {
312. Log.d(TAG, "getLatestNews");
313. NewsContainer container = getNews();
314. if (container != null)
315. {
316. ArrayList data = container.getNewsContainer();
317. if (data != null && data.size() > 0 && data.get(0) != null && data.get(0).getTitle() != null)
318. {
319. Log.d(TAG, "getLatestNews: successfully retrieved " + data.size() + " records");
320. return data.get(0);
321. }
322. }
323. Log.w(TAG, "getLatestNews: no data returned");
324. return null;
325. }
326. }