在列表中添加值后，无法检索出来
原问题来自于CSDN问答频道，更多解决方案见：http://ask.csdn.net/questions/1879
问题描述：
在一个列表中我使用add(int,Object)方法添加了一个值，但是当我使用get(int)方法检索值的时候，却还是获得上次添加的值，并不是这次新添加的值。
谁能给出适当的建议呢？
我使用的下面的代码：
public static List getCompanyName(String user_id) { List<CustomerList> fetchDatefromID = new ArrayList<CustomerList>(); CustomerList tempProgram = new CustomerList(); String result = ""; InputStream is = null; ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); nameValuePairs.add(new BasicNameValuePair("q", "" + user_id)); // http post try { HttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost( "https://erestaurantonline.co.uk/kernow_mobile/customer_search.php?"); httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); is = entity.getContent(); } catch (Exception e) { Log.e("log_tag", "Error in http connection " + e.toString()); } // convert response to string 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(); result = sb.toString(); } catch (Exception e) { Log.e("log_tag", "Error converting result " + e.toString()); } // parse json data try { JSONArray jArray = new JSONArray(result); for (int i = 0; i < jArray.length(); i++) { JSONObject json_data = jArray.getJSONObject(i); if (json_data.getString("company") != null) { tempProgram.setCompanyName(json_data.getString("company")); tempProgram.setID(json_data.getString("id")); fetchDatefromID.add(i, tempProgram); } } } catch (JSONException e) { Log.e("log_tag", "Error parsing data " + e.toString()); } for (int i = 0; i < fetchDatefromID.size(); i++) { Log.v("log_tag","DataMy : "+fetchDatefromID.get(i).getCompanyName().toString()); } return fetchDatefromID;}解决方案：
把下面的代码：
if (json_data.getString("company") != null) { tempProgram.setCompanyName(json_data.getString("company")); tempProgram.setID(json_data.getString("id")); fetchDatefromID.add(i, tempProgram); }换成：
if (json_data.getString("company") != null) { tempProgram = new CustomerList(); tempProgram.setCompanyName(json_data.getString("company")); tempProgram.setID(json_data.getString("id")); fetchDatefromID.add(i, tempProgram); }
否则，list中的每一项都要引用同样的对象，那样的话总是显示你最后一次输入的数据。