参考 http://blog.sina.com.cn/s/blog_6923201d01011t6h.html

http://www.cnphp6.com/archives/106137

遇到的问题：

1. 找不到NameValuePair cannot be resolve....,

2.  ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();

   解决方法： build path中删除无效的jar路径，添加  eclipse安装路径下 sdk\platforms\android-23\optional  路径下的jar文件

3. 在主线程中不能进行耗时操作以及在非UI线程中，禁止修改UI：

   修改部分代码如下：

4.        b1.setOnClickListener(new Button.OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubnew Thread(){@SuppressWarnings("deprecation")@Overridepublic void run() {ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();// http gettry {HttpClient httpclient = new DefaultHttpClient();HttpGet httpget = new HttpGet("http://wlan_address:80/test.php");
   //                            HttpGet httpget = new HttpGet(
   //                                       "http://computer_address:80/test.php");HttpResponse response = httpclient.execute(httpget);HttpEntity entity = response.getEntity();is = entity.getContent();} catch (Exception e) {Log.e("log_tag", "Error in http connection" + e.toString());}// convert response to stringtry {BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);sb = new StringBuilder();sb.append(reader.readLine() + "\n");String line = "0";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());}int ct_id;String ct_name;try {jArray = new JSONArray(result);JSONObject json_data = null;for (int i = 0; i < jArray.length(); i++) {json_data = jArray.getJSONObject(i);ct_id = json_data.getInt("id");ct_name = json_data.getString("name");Message msg = new Message();msg.what = 0x123;msg.obj = ct_name;Log.e("NAME", ct_name);myhandler.sendMessage(msg);// tv.append(ct_name + " \n");}} catch (JSONException e1) {// Toast.makeText(getBaseContext(), "No City Found"// ,Toast.LENGTH_LONG).show();} catch (ParseException e1) {e1.printStackTrace();}}}.start();}});

5. private final Handler myhandler = new Handler(){public void handleMessage(Message msg){if(msg.what == 0x123){System.out.println("------->" + msg.obj);tv.append(msg.obj + "\n");}}};

   6. org.apache.http.conn.HttpHostConnectException: Connection to http://localhost refused in android

   当在模拟器中运行程序时，ip地址是自己电脑的真实ip地址

   当在真机上运行时，ip地址是cmd-》ipconfig 下wlan的ip地址 （真机和电脑需要在同一无线局域网下）

   7. PHP代码修改

6. <?php
   $link=mysqli_connect("localhost","root","123456","test");
   mysqli_set_charset($link, "utf8");
   //mysqli_select_db("test",$link);
   $sql=mysqli_query($link,"select * from teacher ");
   while($row=mysqli_fetch_assoc($sql))
   $output[]=$row;
   print(json_encode($output));
   mysqli_close($link);?>