为什么如果我向服务器上的数据库请求超过 100 行，结果却什么也得不到？

Question

我正在尝试从我的服务器接收整个 table 数据到我的应用程序。这个功能我只需要在第一次访问时能够在设备上加载分配的 table 并在将来使用新数据动态更新它。我遇到的问题是 table 由 600 行组成，当我从我的 php 文件中生成 json 时，我在 Android 的答案 reader 中生成了 json就是empty.I想办法接收整个table但是解决不了，希望大家帮帮我。

如果我将行的值减少到 100，我没有问题，但我不能全部发送，我想知道是否有另一种方法可以接收整个 table 或更大的文件。

这是我在应用程序中的 class 调用服务器和 php 文件以提取 table:

 private String makeHttpRequestJsonListSpecific(String languageTOpass, String urlAdress) {
    String responce=null;
    Log.v(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific : SEND MY REQUEST....");
 tringBuffer data_post = new StringBuffer();
try {
        data_post.append(URLEncoder.encode("Language","UTF-8"));
        data_post.append("=");
        data_post.append(URLEncoder.encode(languageTOpass,"UTF-8"));
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } 
    String json = "";
    InputStream responseStream = null;
    String logMess = "";
    long startTime;
    long stopTime;
    long elapsedTime;

    try {

        byte[] postDataBytes = data_post.toString().getBytes("UTF-8");

        JSONObject Language_Json = new JSONObject();
        Language_Json.put("Language",languageTOpass);

        String Message_send = Language_Json.toString();
        Log.v(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific : IL VALORE DI Message_send...." + Message_send);
     URL url = new URL(urlAdress);

    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    conn.setDoOutput(true);
    conn.setDoInput(true);
    conn.setRequestMethod("POST");
    conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
    conn.setRequestProperty("Accept", "application/json");
    conn.setUseCaches(true);
    conn.connect();

    OutputStreamWriter request = new OutputStreamWriter(conn.getOutputStream());
    request.write(Message_send);
    request.flush();
    request.close();

        
        InputStream inputStream = (InputStream) conn.getContent();
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: IL VALORE DI READR--- " + reader.toString());
        StringBuilder result = new StringBuilder();
        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: IL VALORE DI RESULT--- " + result.toString());
        String line;
        
        while ((line = reader.readLine()) != null) {
            Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: SONO NEL CICLO DI SCRITTURA DELLA RISPOSTA--- " + conn);
            result.append(line).append("\n");
        }
        json = result.toString();
        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: ************************************************************ " );
        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: ************************************************************ " );
        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: THE DIMENSION OF THE RECEPTION : " + json.getBytes().length);
        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: ************************************************************ " );
        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: ************************************************************ " );
        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: ************************************************************ " );
        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: RESOULT : " + json);

        conn.disconnect();

        Log.d(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific: Connection --- " + conn);

    } catch (IOException | JSONException e ) {
        Log.e(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific:ERROR MESSAGE --- " + e.getMessage());
        Log.e(TAG, "GetSpecificListFromServer: makeHttpRequestJsonListSpecific:ERROR MESSAGE Cause --- " + e.getCause());
    }
    return json;
}

这是我在服务器上生成 json 文件以发送到我的应用程序的 php 文件：

<? php 
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL | E_STRICT);

$host ='localhost';
$username ='***';
$pwd ='**';
$db ='MYDB';
$responce =array();
$responce ["success"]= 0 ;
$responce ["message"]= "Error at start";
$json=file_get_contents('php://input');
$obj_json=json_decode($json,TRUE);
if(isset($obj_json)){
   $language=$obj_json['Language'];
   $connect = mysqli_connect($host,$username,$pwd,$db) or die('Unabletp connect');
   if(mysqli_connect_error($connect)){
    echo ("Fallita la connessione al data base".mysqli_connect_error());
    $responce ['success']=0;
    $responce ['message']="NO CONNECTION  NEW_SPECIFIC_PRODUCT";
}else{
        // I SET MY SEARCH QUERY
        // CHECK THAT THE LANGUAGE IS ITALIAN
        if(strcasecmp($language,"it")== 0){
            $sql_find = ("SELECT FAMILY_PRODUCT,CATEGORY_PRODUCT,SPECIFIC_PRODUCT,NAME_SPECIFIC FROM NEW_SPECIFIC_PRODUCT_IT;") ;
            $result= mysqli_query($connect,$sql_find) or  die ("Error: ". mysqli_error($connect)." with query ");
    if(mysqli_num_rows($result)> 0){
                $responce ["success"]= 1 ;
                $i=0;
                
                while ($row = mysqli_fetch_array($result)){
                
                    $name_specific=$row["NAME_SPECIFIC"];
                    $result_array[$i]= array("FAMILY_PRODUCT" => $row["FAMILY_PRODUCT"],"CATEGORY_PRODUCT"  =>$row["CATEGORY_PRODUCT"],"SPECIFIC_PRODUCT" => $row["SPECIFIC_PRODUCT"],"NAME_SPECIFIC" => $name_specific);
                    $i++;
                }
                
                $responce ['success']=1;
                $responce ['message']="I VALORI SONO STATI TROVATI";
                
                }else{
                # code...
                $responce ['success']=0;
                $responce ['message']="NO DATA IN  NEW_SPECIFIC_PRODUCT_IT";
            }
        }else{
            // THE TELEPHONE LANGUAGE IS NOT ITALIAN
            echo ("IL VALORE DI language non è it.....".$language);
            $sql_find = ("SELECT * FROM NEW_SPECIFIC_PRODUCT_EN;") ;
            $result= mysqli_query($connect,$sql_find) or  die ("Error: ". mysqli_error($connect)." with query ");
            if(mysqli_num_rows($result)> 0){
                $responce ["success"]= 1 ;
                $i=0;
                while ($row = mysqli_fetch_array($result)){
                    $result_array[$i]= array("FAMILY_PRODUCT" =>$row["FAMILY_PRODUCT"],"CATEGORY_PRODUCT"=>$row["CATEGORY_PRODUCT"],"SPECIFIC_PRODUCT"=>$row["SPECIFIC_PRODUCT"],"NAME_SPECIFIC"=>$row["NAME_SPECIFIC"]);
                    $i++;
                }
                
            }else{
                # code...
                $responce ['success']=0;
                $responce ['message']="NO DATA IN  NEW_SPECIFIC_PRODUCT_EN";
            }
        }           
mysqli_close($connect);
array_push($responce,$result_array);
}
}else{
   $responce['success']=0;
   $responce['message']="Parameters are not correct";
echo json_encode($responce);
 }
header('Content-type:application/json');
echo json_encode($responce);
   ?>

当我去验证我发送的 json 结果是空的，当我没有收到任何东西时，是否有另一种方法可以接收整个 table？在此先感谢您的帮助。

我按要求添加日志文件：

GetSpecificListFromServer: makeHttpRequestJsonListSpecific: IL VALORE DI READR--- java.io.BufferedReader@---
GetSpecificListFromServer: makeHttpRequestJsonListSpecific: IL VALORE DI RESULT--- 
GetSpecificListFromServer: makeHttpRequestJsonListSpecific: ************************************************************ 
GetSpecificListFromServer: makeHttpRequestJsonListSpecific: ************************************************************ 
GetSpecificListFromServer: makeHttpRequestJsonListSpecific: LA DIMENSIONE DELLA RICEZIONE : 0
GetSpecificListFromServer: makeHttpRequestJsonListSpecific: ************************************************************

Answer 1

我已经找到问题的解决方案并报告它，以便如果它对某人有用，他们可以使用它。经过多次检查后，我注意到问题是我的 Json 不是在我的 php 文件中创建的，因此使用我的数据库中由字符串值组成的部分我试图检查 Json 生成错误通过添加此代码立即鼠标生成 Json:

echo json_encode($responce);
switch (json_last_error()) {
    case JSON_ERROR_NONE:
        echo ' - No errors';
    break;
    case JSON_ERROR_DEPTH:
        echo ' - Maximum stack depth exceeded';
    break;
    case JSON_ERROR_STATE_MISMATCH:
        echo ' - Underflow or the modes mismatch';
    break;
    case JSON_ERROR_CTRL_CHAR:
        echo ' - Unexpected control character found';
    break;
    case JSON_ERROR_SYNTAX:
        echo ' - Syntax error, malformed JSON';
    break;
    case JSON_ERROR_UTF8:
        echo ' - Malformed UTF-8 characters, possibly incorrectly encoded';
    break;
    default:
        echo ' - Unknown error';
    break;
}
 echo PHP_EOL;

通过这次验证，我的错误类型是“格式错误的 UTF-8 字符，可能编码不正确” 所以我在提取我的查询结果之后插入一个 UTF-8 解码，然后再将它插入我的答案数组，然后我将在 Json 中编码。这使我能够正确创建 Json 并克服由不允许编码的特定字符指示的块。

$name_specific=utf8_encode($row["NAME_SPECIFIC"]);

希望能帮到和我同街区的朋友，谢谢大家

为什么如果我向服务器上的数据库请求超过 100 行，结果却什么也得不到？

Why if I request more than 100 rows to my database on the server do I get nothing as a result?

php

post

android

json

outputstream