如何使用JSON從外部數據庫填充微調框

Question

我想從與外部數據庫進行通信的php中獲取JSON的微調框。我不斷收到JSON異常錯誤。

我想獲得一個下拉菜單中，我可以選擇的寵物類型（即狗，貓，魚等）

這是JSON我從JSONParser得到：

{"success":1,"0":{"pets_kind":"dog"},"1":{"pets_kind":"cat"}} 

這是我的PHP：

DB_Functions.php：

public function getPetKind(){ 
    $result = array(); 
    $fetch = mysql_query("SELECT pets_kind FROM PetsList") or die(mysql_error()); 

    while ($row = mysql_fetch_array($fetch, MYSQL_ASSOC)) { 
     $row_array['pets_kind'] = $row['pets_kind']; 
     array_push($result,$row_array); 
    } 
    return $result; 
} 

的index.php：

}else if($tag == 'getpetkind'){ 
    $pets_kind = array(); 
    $pets_kind = $db->getPetKind(); 
    if($pets_kind != false){ 
     $response = array(); 
     $response["success"]=1; 
     foreach ($pets_kind as $row) { 
      $row_array['pets_kind'] = $row['pets_kind']; 
      array_push($response,$row_array); 
     } 
     echo json_encode($response); 

    } 

填充下拉的AsyncTask我在OnCreate()撥打：

private class FillDropDown extends AsyncTask<String,Void,JSONObject>{ 

    @Override 
    protected void onPreExecute(){ 
     super.onPreExecute(); 
     petsKindDropDown = (Spinner) findViewById(R.id.petsKindDropDown); 

    } 
    @Override 
    protected JSONObject doInBackground(String... args){ 

     UserFunctions userFunctions = new UserFunctions(); 
     JSONObject json = userFunctions.getPetsKind(); 
     return json; 
    } 
    @Override 
    protected void onPostExecute(JSONObject json){ 
     /** 
     * Checks for success message 
     */ 
     try{ 
      if(json.getString(KEY_SUCCESS) != null){ 

        ArrayList<String> kind = new ArrayList<String>(); 
        JSONArray jsonArr = new JSONArray(json.optString("pets_kind")); 
        for(int i = 0; i < jsonArr.length(); i++){ 
         JSONObject jsonObject = jsonArr.getJSONObject(i); 
         kind.add(jsonObject.optString("pets_kind")); 
        } 

        petsKindDropDown.setAdapter(new ArrayAdapter<String>(AddPet.this, 
          android.R.layout.simple_spinner_dropdown_item,kind)); 
      } 

      else{ 
       addPetAlertText.setText("Error occured in Filling Drop down"); 
      } 
     } catch (JSONException e){ 
      e.printStackTrace(); 
     } 
    } 
} 

錯誤：

W/System.err: org.json.JSONException: End of input at character 0 of 
W/System.err:  at org.json.JSONTokener.syntaxError(JSONTokener.java:449) 
W/System.err:  at org.json.JSONTokener.nextValue(JSONTokener.java:97) 
W/System.err:  at org.json.JSONArray.<init>(JSONArray.java:92) 
W/System.err:  at org.json.JSONArray.<init>(JSONArray.java:108) 
W/System.err:  at com.adicili.petdetective.AddPet$FillDropDown.onPostExecute(AddPet.java:133) 
W/System.err:  at com.adicili.petdetective.AddPet$FillDropDown.onPostExecute(AddPet.java:103) 
W/System.err:  at android.os.AsyncTask.finish(AsyncTask.java:651) 
W/System.err:  at android.os.AsyncTask.-wrap1(AsyncTask.java) 
W/System.err:  at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668) 
W/System.err:  at android.os.Handler.dispatchMessage(Handler.java:102) 
W/System.err:  at android.os.Looper.loop(Looper.java:148) 
W/System.err:  at android.app.ActivityThread.main(ActivityThread.java:5417) 
W/System.err:  at java.lang.reflect.Method.invoke(Native Method) 
W/System.err:  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
W/System.err:  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 

Answer 1

更改PHP功能是這樣的：

public function getPetKind(){ 
    $result = array(); 
    $fetch = mysql_query("SELECT pets_kind FROM PetsList") or die(mysql_error()); 
    while ($row = mysql_fetch_array($fetch, MYSQL_ASSOC)) { 
     $result[] = $row; 
    } 
    return $result; 
} 

，並建立像這樣JSON：

$response = array(); 
$pets_kind = $db->getPetKind(); 
if(count($pets_kind) > 0){ 
    $response["success"]=1; 
    $response["result"]=$pets_kind; 
}else{ 
    $response["success"]=0; 
    $response["result"]='no pet found'; 
} 
echo json_encode($response); 

，然後你的java代碼如下所示：

ArrayList<String> kind = new ArrayList<String>(); 
JSONArray jsonArr = json.getJSONArray("result"); 
for(int i = 0; i < jsonArr.length(); i++){ 
    JSONObject jsonObject = jsonArr.getJSONObject(i); 
    kind.add(jsonObject.optString("pets_kind")); 
}