如何从php检索变量到android？

Question

任何人都可以帮助我了解如何将变量从 php 检索到 android？ 我看过很多例子。但就我而言，我在 Backgroundworker 中执行此操作。 另外，我想在我的 onPostExecute 方法上使用变量。

当我在 onPostExecute 中烘烤结果时，我可以看到它显示了我需要的正确数据（如数组）。有什么办法可以分开装吗？我想根据偏好保存它以在下一个活动中使用。

请帮助我。提前感谢您的时间。 以下是代码：

Backgroundworker.java

public class updateData extends AsyncTask<String, String, String> {

    @Override
    protected String doInBackground(String... params) {
        HttpURLConnection conn = null;

        try {
            URL url;
            url = new URL(params[0]);
            conn = (HttpURLConnection) url.openConnection();

            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            OutputStream outputStream = httpURLConnection.getOutputStream();
            BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
            String post_data = "";
            bufferedWriter.write(post_data);
            bufferedWriter.flush();
            bufferedWriter.close();
            outputStream.close();
            InputStream inputStream = httpURLConnection.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.ISO_8859_1));
            String result = "";
            String line = "";
            while ((line = bufferedReader.readLine()) != null) {
                result += line;
            }

            bufferedReader.close();
            inputStream.close();
            httpURLConnection.disconnect();

            JSONObject jsonobj = new JSONObject(result);
            String id = jsonobj.getString("id");
            String address = jsonobj.getString("address");

            return result;

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (JSONException e) {

            e.printStackTrace();
        } finally {
            if (conn != null) {
                conn.disconnect();
            }
        }
        return null;
    }

    @Override
    protected void onPostExecute(String result) {
    // where I want to use id and address
    }

}

php代码

 <?php 
require "conn.php";

$uname = $_GET["email"];   

$sql="select * from users where email = '".$uname."'  ";

$result=mysqli_query($conn,$sql);
if($result){
    while($row=mysqli_fetch_array($result)){
        $id=$row['user_id'];
        $address=$row['address'];
    } 

$result2["id"] = $uname;
$result2["address"] = $address;
echo json_encode($result2);

}

?>

Answer 1

看来您必须解码 JSON：

public void DecodeJson(String JSON){
    try {
        JSONArray arrayJson = StringToJSONarray(JSON); //String to JSON Array
        JSONObject json = arrayJson.getJSONObject(0); /*In case you have more than one JSONs (not your case)*/
        int decoded_id = json.getInt("id")); /*Set the same name as in your PHP file ("id")*/
        String decoded_address = json.getString("address")); /*Set the same name as in your PHP file ("address")*/

    }catch (JSONException e){
        /*TODO Handle exception*/
    }
}

private JSONArray StringToJSONarray(String JSON) throws JSONException {
    return new JSONArray(JSON);
}

希望对你有帮助！

Answer 2

在您的 php 代码中将 echo 更改为 return。

<?php 
   require "conn.php";
   $uname = $_GET["email"];   
   $sql="select * from users where email = '".$uname."'  ";
   $result=mysqli_query($conn,$sql);
   if($result){
    while($row=mysqli_fetch_array($result)){
    $id=$row['user_id'];
    $address=$row['address'];
   } 
   $result2["id"] = $uname;
   $result2["address"] = $address;
   return json_encode($result2);
  }
?>

在java代码中：

public class updateData extends AsyncTask<String, String, String> {

@Override
protected String doInBackground(String... params) {
    HttpURLConnection conn = null;

    try {
        URL url;
        url = new URL(params[0]);
        conn = (HttpURLConnection) url.openConnection();

        HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
        httpURLConnection.setRequestMethod("POST");
        httpURLConnection.setDoOutput(true);
        httpURLConnection.setDoInput(true);
        OutputStream outputStream = httpURLConnection.getOutputStream();
        BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
        String post_data = "";
        bufferedWriter.write(post_data);
        bufferedWriter.flush();
        bufferedWriter.close();
        outputStream.close();
        InputStream inputStream = httpURLConnection.getInputStream();
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.ISO_8859_1));
        String result = "";
        String line = "";
        while ((line = bufferedReader.readLine()) != null) {
            result += line;
        }

        bufferedReader.close();
        inputStream.close();
        httpURLConnection.disconnect();

        return result;

    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (JSONException e) {

        e.printStackTrace();
    } finally {
        if (conn != null) {
            conn.disconnect();
        }
    }
    return null;
}

@Override
protected void onPostExecute(String result) {
         JSONObject jsonobj = new JSONObject(result);
        String id = jsonobj.getString("id");
        String address = jsonobj.getString("address");
}
}

在 OnCreate 方法中调用你的类：

new updateData("http://exampleurl.com/api").execute();