php - Json 使用 WHERE column = $variable 读取 mysql 列

Question

我想在同一个 session 中按此顺序实现以下目标:

1. 获取android变量(imei)
2. 发送变量到php
3. 在sql中使用变量
4. 将结果发送回android

我使用以下内容:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_contacts);

     // 01 - first i get imei
     TelephonyManager mngr = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE); 
     IMEI = mngr.getDeviceId();

    // 02 - then i call class to post imei to php
    new loadData().execute();

     // 03 - on php side i use "select ... where $imei ..." 

    // 04 - get the results back to android
// (yes i am aware that this method is commented out, i will explain why below)
    //accessWebService();

    }

发布:

    class loadData extends AsyncTask<String, Integer, String> {
    private StringBuilder sb;
    private ProgressDialog pr;
    private HttpResponse req;
    private InputStream is;

    @Override
    protected void onPreExecute() {
        super.onPreExecute();

    }

    @Override
    protected String doInBackground(String... arg0) {

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

          String imeino = String.valueOf(IMEI);

            nameValuePairs.add(new BasicNameValuePair("imeino",imeino));

                try
                {
                HttpClient httpclient = new DefaultHttpClient();
                    HttpPost httppost = new HttpPost("http://blah/contacts.php");
                    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                    HttpResponse response = httpclient.execute(httppost); 
                    HttpEntity entity = response.getEntity();
                    is = entity.getContent();
                    InputStreamReader ireader = new InputStreamReader(is);
                    BufferedReader bf = new BufferedReader(ireader);
                    sb = new StringBuilder();
                    String line = null;
                    while ((line = bf.readLine()) != null) {
                        sb.append(line);
                    }
                    Log.e("pass 1", "connection success ");

            }
                catch(Exception e)

            {       
                    Log.e("Error Send",e.toString());
            }
                return id;     

    }
}

获取

 private class JsonReadTask extends AsyncTask<String, Void, String> {
      @Override
      protected String doInBackground(String... params) {
       HttpClient httpclient = new DefaultHttpClient();
       HttpPost httppost = new HttpPost(params[0]);
       try {
        HttpResponse response = httpclient.execute(httppost);
        jsonResult = inputStreamToString(response.getEntity().getContent()).toString();

        System.out.println("jsonResult: "+jsonResult);
       }


       catch (ClientProtocolException e) {
        e.printStackTrace();
       } catch (IOException e) {
        e.printStackTrace();
       }
       return null;
      }

      private StringBuilder inputStreamToString(InputStream is) {
       String rLine = "";
       StringBuilder answer = new StringBuilder();
       BufferedReader rd = new BufferedReader(new InputStreamReader(is));

       try {
        while ((rLine = rd.readLine()) != null) {
         answer.append(rLine);
        }
       }

       catch (IOException e) {
        // e.printStackTrace();
        Toast.makeText(getApplicationContext(),
          "Error..." + e.toString(), Toast.LENGTH_LONG).show();
       }
       return answer;
      }

      @Override
      protected void onPostExecute(String result) {
       ListDrwaer();
      }
     }// end async task

     public void accessWebService() {
      JsonReadTask task = new JsonReadTask();
      // passes values for the urls string array
      task.execute(new String[] { "http://blah/contacts.php" });
     }

     // build hash set for list view
     public void ListDrwaer() {

      try {
       JSONObject jsonResponse = new JSONObject(jsonResult);
       JSONArray jsonMainNode = jsonResponse.optJSONArray("contact_info");

       for (int i = 0; i < jsonMainNode.length(); i++) {
        JSONObject jsonChildNode = jsonMainNode.getJSONObject(i);
        String name = jsonChildNode.optString("Name");
        String number = jsonChildNode.optString("Number");
        String username = jsonChildNode.optString("Username");
        String status = jsonChildNode.optString("Status");

        System.out.println("jsonResult: "+jsonResult);
        System.out.println("getName: "+name);
        System.out.println("getNumber: "+number);
        System.out.println("getUsername: "+username);
        System.out.println("getStatus: "+status);

       }
      } catch (JSONException e) {
          System.out.println("Json Error" +e.toString());
          Toast.makeText(getApplicationContext(), "Error" + e.toString(), Toast.LENGTH_SHORT).show();
      }
}

PHP:

    <?php

include 'config.php';

$con=mysql_connect("$servername", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$dbname")or die("cannot select DB");

$imei = isset($_POST['imeino']) ? $_POST['imeino'] : '';
//$imei = "000000000000000";

$sql = "select * from users WHERE IMEI ='$imei'"; 
$result = mysql_query($sql);
$json = array();

if(mysql_num_rows($result)){
while($row=mysql_fetch_assoc($result)){
$json['contact_info'][]=$row;
}
}
mysql_close($con);
echo json_encode($json); 

    $f = fopen("log.txt", "w");
    fwrite($f, print_r($json, true));
    fclose($f);  

?>  

好的，下面是代码的故事:

当我只是 POST [ new loadData().execute() ] 而不是 GET [ accessWebService(); ] 时，我可以读取我的 $imei = isset($_POST['imeino']) ? $_POST['imeino'] : ''; 变量为 0000000000000 但当然我无法返回结果，因为 accessWebService() 被注释掉了。

然而，当我取消注释 accessWebService() 时，我可以将结果返回到 android 但它们是 null 因为现在 $imei = isset($_POST[' imeino'])？ $_POST['imeino'] : ''; 为空。

总结一下:

每当我调用 GET 方法时，我都会丢失我的 POST 变量!

Answer 1

PHP

要在 PHP 中同时支持 GET 和 POST 变量，您可以使用 $_REQUEST :

$imei = isset($_REQUEST['imeino']) ? $_REQUEST['imeino'] : '';

检查参数是否已设置也是明智的做法，如果未设置则返回错误:

if ( empty($imei) ) {
    echo json_encode( array( 'error' => 'Missing imeino parameter' ) );
    return;
}

而且，非常重要的是，在将输入传递给 mysql 之前对其进行清理。这很危险:

$sql = "select * from users WHERE IMEI ='$imei'"; 

因为有人可能会使用 contacts.php?imeino=';DROP TABLE users' 调用您的 PHP 脚本。 See here获取更多信息。

顺便说一下，PHP's mysql module is deprecated ;我建议使用 PDO .

Java

访问 API 的 GET 方法只需要一个小改动，将 imeino 参数传递给您的 PHP 脚本:

 public void accessWebService( String imei ) {
    JsonReadTask task = new JsonReadTask();     
    task.execute(new String[] { "http://blah/contacts.php?imeino=" + imei });
 }

并且，您需要使用 IMEI 调用 accessWebService。