对我来说，关键是创建一个名为URLWithParams的类或其他类，因为AsyncTask将只允许发送一种类型的输入，并且我需要URL和HTTP请求的参数。
public class URLWithParams { public String url; public List<NamevaluePair> namevaluePairs; public URLWithParams() { namevaluePairs = new ArrayList<NamevaluePair>(); }}然后将其发送到JSONClient：
public class JSonClient extends AsyncTask<URLWithParams, Void, String> { private final static String TAG = "JSONClient"; ProgressDialog progressDialog ; GetJSonListener getJSONListener; public JSonClient(GetJSonListener listener){ this.getJSonListener = listener; } @Override protected String doInBackground(URLWithParams... urls) { return connect(urls[0].url, urls[0].namevaluePairs); } public static String connect(String url, List<NamevaluePair> pairs) { HttpClient httpclient = new DefaultHttpClient(); if(url == null) { Log.d(TAG, "want to connect, but url is null"); } else { Log.d(TAG, "starting connect with url " + url); } if(pairs == null) { Log.d(TAG, "want to connect, though pairs is null"); } else { Log.d(TAG, "starting connect with this many pairs: " + pairs.size()); for(NamevaluePair dog : pairs) { Log.d(TAG, "example: " + dog.toString()); } } // Execute the request HttpResponse response; try { // Prepare a request object HttpPost httpPost = new HttpPost(url); httpPost.setEntity(new UrlEnpredFormEntity(pairs)); response = httpclient.execute(httpPost); // Examine the response status Log.i(TAG,response.getStatusLine().toString()); BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8")); String json = reader.readLine(); return json; } catch (ClientProtocolException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; } @Override protected void onPostExecute(String json ) { getJSONListener.onRemoteCallComplete(json); } public interface GetJSonListener { public void onRemoteCallComplete(String jsonFromNet); }}然后从我的主班这样叫
public class BookCatalog implements GetJSonListener { private final String TAG = this.getClass().getSimpleName(); private String catalog_url = "URL"; private void getCatalogFromServer() { URLWithParams mURLWithParams = new URLWithParams(); mURLWithParams.url = catalog_url; try { JSonClient asyncPoster = new JSonClient(this); asyncPoster.execute(mURLWithParams); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } @Override public void onRemoteCallComplete(String jsonBookCatalogList) { Log.d(TAG, "received json catalog:"); Log.d(TAG, jsonBookCatalogList); JSonObject bookCatalogResult; try { bookCatalogResult = (JSONObject) new JSonTokener(jsonBookCatalogList).nextValue(); JSonArray books = bookCatalogResult.getJSonArray("books"); if(books != null) { ArrayList<String> newBookOrdering = new ArrayList<String>(); int num_books = books.length(); BookCatalogEntry temp; DebugLog.d(TAG, "apparently we found " + Integer.toString(num_books) + " books."); for(int book_id = 0; book_id < num_books; book_id++) { JSonObject book = books.getJSonObject(book_id); String title = book.getString("title"); int version = book.getInt("price"); } } } catch (JSonException e) { e.printStackTrace(); } }}
