php - 将 $_POST ['whatever' 的参数发送到 PHP 文件时出现问题

Question

我正在尝试将 POST 发送到文件 php 以在 mysql 数据库中插入一些值。当我发送参数时， if($_POST['nombre']){...} 收到带有空值的 $_POST。我卡住了。这是代码

JSONParse.java

public class JSONParser {

    HttpURLConnection urlConnection= null;
    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    public JSONParser() {

    }

    public JSONObject makeHttpRequest(String url, String method, ContentValues params) {

        try {
            if(method == "POST"){
                URL url1= new URL(url);
                urlConnection=(HttpURLConnection) url1.openConnection();
                urlConnection.setRequestMethod("POST");
                urlConnection.connect();
                is = urlConnection.getInputStream();
            }else if(method == "GET"){
                url += "?" + params;
                URL url1= new URL(url);
                urlConnection=(HttpURLConnection) url1.openConnection();
                urlConnection.setRequestMethod("GET");
                urlConnection.connect();
                is = urlConnection.getInputStream();
            }           

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        return jObj;

    }
}

AltaUserFragment.java`

public class AltaUserFragment extends Fragment {

    private ProgressDialog pDialog;

    private static final String TAG_SUCCESS = "success";
    private static final String TAG_USERS = "usuarios";
    private static final String TAG_USER = "usuario";
    private static final String TAG_CONTRA = "contrasena";

    JSONArray users = null;
    private ContentValues params;

    JSONParser jParser = new JSONParser();

    private static String url_alta_user = "https://serverhost/android/create_user.php";

    public AltaUserFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_alta_user, container, false);
        Button btnAlta = (Button) view.findViewById(R.id.btnAltaUser);
        btnAlta.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                new AltaUsario().execute();
            }
        });
        return view;
    }

    class AltaUsario extends AsyncTask<String, String, String> {

        TextView txtNombre = (TextView) getView().findViewById(R.id.txtNombre);
        TextView txtUsuario = (TextView) getView().findViewById(R.id.txtUsuario);
        TextView txtEmail = (TextView) getView().findViewById(R.id.txtEmail);
        TextView txtContra1 = (TextView) getView().findViewById(R.id.txtContra1);
        TextView txtContra2 = (TextView) getView().findViewById(R.id.txtContra2);

        String nombre = txtNombre.getText().toString();
        String usuario = txtUsuario.getText().toString();
        String email = txtEmail.getText().toString();
        String contra1 = txtContra1.getText().toString();
        String contra2 = txtContra2.getText().toString();

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(getActivity());
            pDialog.setMessage("Checking user. Please wait...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

        @Override
        protected String doInBackground(String... strings) {
            params = new ContentValues();
            params.put("nombre",nombre );
            params.put("usuario",usuario );
            params.put("contrasena", contra1 );
            params.put("email",email);

            JSONObject json = jParser.makeHttpRequest(url_alta_user, "POST", params);

            try {
                // Checking for SUCCESS TAG
                int success = json.getInt(TAG_SUCCESS);

                if (success == 1) {
                    // successfully created product
                    Intent i = new Intent(getContext(), MainActivity.class);
                    startActivity(i);

                    // closing this screen
                    getActivity().getSupportFragmentManager().popBackStack();

                } else {

                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
            return null;
        }

        protected void onPostExecute(String file_url) {
            // dismiss the dialog once done
            pDialog.dismiss();
        }
    }
}
`

create_user.php

<?php

/*
 * Following code will create a new product row
 * All product details are read from HTTP Post Request
 */

// array for JSON response
$response = array();

// include db connect class
require_once __DIR__ . '/db_connect.php';

// connecting to db
$con = new DB_CONNECT();
$con->connect();

// check for required fields
if (isset($_POST['nombre']) && isset($_POST['usuario']) && isset($_POST['contrasena']) && isset($_POST['email'])) {

    $nombre = $_POST['nombre'];
    $usuario = $_POST['usuario'];
    $contrasena = $_POST['contrasena'];
    $email = $_POST['email'];

    // mysql inserting a new row
    $result = mysqli_query($con->myconn, "INSERT INTO users(nombre, usuario, contrasena, email) VALUES('$nombre', '$usuario', '$contrasena', '$email')");

    // check if row inserted or not
    if ($result) {
        // successfully inserted into database
        $response["success"] = 1;
        $response["message"] = "User successfully created.";

        // echoing JSON response
        echo json_encode($response);
    } else {
        // failed to insert row
        $response["success"] = 0;
        $response["message"] = "Oops! An error occurred.";

        // echoing JSON response
        echo json_encode($response);
    }
} else {
    // required field is missing
    $response["success"] = 0;
    $response["message"] = "Required field(s) is missing";

    // echoing JSON response
    echo json_encode($response);
}
?>

Answer 1

我对“POST”有同样的问题。您应该考虑使用 volley 库 https://developer.android.com/training/volley/index.html ，我认为它可以解决你的问题。在您的应用程序 gradle 中添加所需的依赖项并在单击按钮时使用 volley 方法

insert.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            final String feedback = feed.getText().toString();
            if(feedback.equals("")){
                Toast.makeText(getBaseContext(),"please fill all fields",Toast.LENGTH_SHORT).show();

            }

            final ProgressDialog loading =
                    ProgressDialog.show(feedbackPage.this, "Setting up connection...", null, true, true);
            //delay insertion by x sec so that course code can be properly fetched
            mhandler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    if(loading.isShowing())
                        loading.dismiss();
                    StringRequest request = new StringRequest(Request.Method.POST, insert_url,
                            new Response.Listener<String>() {

                                @Override
                                public void onResponse(String response) {

                                    dialog.setTitle("Server Response");
                                    dialog.setMessage(response);
                                    dialog.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                                        @Override
                                        public void onClick(DialogInterface dialog, int which) {

                                            feed.setText("");
                                        }
                                    });
                                    AlertDialog alert = dialog.create();
                                    alert.show();
                                }
                            }
                            , new Response.ErrorListener() {

                        @Override
                        public void onErrorResponse(VolleyError error) {

                            Toast.makeText(feedbackPage.this, "error...." + error.toString()
                                    , Toast.LENGTH_SHORT).show();
                        }
                    }) {
                        @Override
                        protected Map<String, String> getParams() throws AuthFailureError {

                            Map<String, String> params = new HashMap<String, String>();
                            params.put("uid", uid);
                            params.put("name", userName);
                            params.put("feed", feedback);
                            return params;
                        }
                    };

                    request.setRetryPolicy(new DefaultRetryPolicy(3000, 5,
                            DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));

                    Singleton.getInstance(feedbackPage.this).addTorequestqueue(request);
                }
            },3000);
        }
    });

您需要一个单例类来获取返回的请求队列:

public class Singleton {

private static Singleton single_instance;
private RequestQueue queue;
private static Context ctx;

private Singleton(Context ctx){
    this.ctx=ctx;
    queue = getQueue();
}

public static synchronized Singleton getInstance( Context ctx){
    if(single_instance == null){
        single_instance = new Singleton(ctx);
    }
    return single_instance;

}

public RequestQueue getQueue(){
    if(queue==null){
        queue = Volley.newRequestQueue(ctx.getApplicationContext());
        return queue;
    }

    return queue;
}

public <T>void addTorequestqueue(Request<T> request){
    queue.add(request);
}

你可以更好地理解它:https://www.youtube.com/watch?v=FL37oah1k8k

希望对您有所帮助!