Question

这是我的编码。那是在Localhost上工作的。当我托管此代码时，该功能无法正常运行。请问，如何解决这个问题？谢谢

Login.java，此代码适用于在Android上登录。此代码包含如何从MySQL获取一些变量。

package com.sudotech.go_learn;

    import java.util.HashMap;
    import java.util.Map;

    import org.json.JSONException;
    import org.json.JSONObject;

    import com.android.volley.Response;
    import com.android.volley.VolleyError;
    import com.android.volley.Request.Method;
    import com.android.volley.toolbox.StringRequest;

    import com.sudotech.go_learn.AppConfig;
    import com.sudotech.go_learn.AppController;
    import com.sudotech.go_learn.Login;
    import com.sudotech.go_learn.MainActivity;
    import com.sudotech.go_learn.R;
    import com.sudotech.go_learn.SQLiteHandler;
    import com.sudotech.go_learn.SessionManager;

    import android.app.Activity;
    import android.app.ProgressDialog;
    import android.content.Intent;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.Toast;

    public class Login extends Activity {
        private static final String TAG = RegisterActivity.class.getSimpleName();
        private Button btnLogin;
        private Button btnLinkToRegister;
        private EditText inputEmail;
        private EditText inputPassword;
        private ProgressDialog pDialog;
        private SessionManager session;
        private SQLiteHandler db;

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

            inputEmail = (EditText) findViewById(R.id.email);
            inputPassword = (EditText) findViewById(R.id.password);
            btnLogin = (Button) findViewById(R.id.btnLogin);
            btnLinkToRegister = (Button) findViewById(R.id.btnLinkToRegisterScreen);

            // Progress dialog
            pDialog = new ProgressDialog(this);
            pDialog.setCancelable(false);

            // SQLite database handler
            db = new SQLiteHandler(getApplicationContext());

            // Session manager
            session = new SessionManager(getApplicationContext());

            // Check if user is already logged in or not
            if (session.isLoggedIn()) {
                // User is already logged in. Take him to main activity
                Intent intent = new Intent(Login.this, MainActivity.class);
                startActivity(intent);
                finish();
            }

            // Login button Click Event
            btnLogin.setOnClickListener(new View.OnClickListener() {

                public void onClick(View view) {
                    String email = inputEmail.getText().toString().trim();
                    String password = inputPassword.getText().toString().trim();

                    // Check for empty data in the form
                    if (!email.isEmpty() && !password.isEmpty()) {
                        // login user
                        checkLogin(email, password);
                    } else {
                        // Prompt user to enter credentials
                        Toast.makeText(getApplicationContext(),
                                "Please enter the credentials!", Toast.LENGTH_LONG)
                                .show();
                    }
                }

            });

            // Link to Register Screen
            btnLinkToRegister.setOnClickListener(new View.OnClickListener() {

                public void onClick(View view) {
                    Intent i = new Intent(getApplicationContext(),
                            SignUpActivity.class);
                    startActivity(i);
                    finish();
                }
            });

        }

        /**
         * function to verify login details in mysql db
         * */
        private void checkLogin(final String email, final String password) {
            // Tag used to cancel the request
            String tag_string_req = "req_login";

            pDialog.setMessage("Logging in ...");
            showDialog();

            StringRequest strReq = new StringRequest(Method.POST,
                    AppConfig.URL_LOGIN, new Response.Listener<String>() {

                @Override
                public void onResponse(String response) {
                    Log.d(TAG, "Login Response: " + response.toString());
                    hideDialog();

                    try {
                        JSONObject jObj = new JSONObject(response);
                        boolean error = jObj.getBoolean("error");

                        // Check for error node in json
                        if (!error) {
                            // user successfully logged in
                            // Create login session
                            session.setLogin(true);

                            // Now store the user in SQLite
                            String uid = jObj.getString("uid");

                            JSONObject user = jObj.getJSONObject("user");
                            String username = user.getString("username");
                            String name = user.getString("name");
                            String email = user.getString("email");
                            String created_at = user
                                    .getString("created_at");

                            // Inserting row in users table
                            db.addUser(username, name, email, uid, created_at);

                            // Launch main activity
                            Intent intent = new Intent(Login.this,
                                    MainActivity.class);
                            startActivity(intent);
                            finish();
                        } else {
                            // Error in login. Get the error message
                            String errorMsg = jObj.getString("error_msg");
                            Toast.makeText(getApplicationContext(),
                                    errorMsg, Toast.LENGTH_LONG).show();
                        }
                    } catch (JSONException e) {
                        // JSON error
                        e.printStackTrace();
                        Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
                    }

                }
            }, new Response.ErrorListener() {

                @Override
                public void onErrorResponse(VolleyError error) {
                    Log.e(TAG, "Login Error: " + error.getMessage());
                    Toast.makeText(getApplicationContext(),
                            error.getMessage(), Toast.LENGTH_LONG).show();
                    hideDialog();
                }
            }) {

                @Override
                protected Map<String, String> getParams() {
                    // Posting parameters to login url
                    Map<String, String> params = new HashMap<String, String>();
                    params.put("email", email);
                    params.put("password", password);

                    return params;
                }

            };

            // Adding request to request queue
            AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
        }

        private void showDialog() {
            if (!pDialog.isShowing())
                pDialog.show();
        }

        private void hideDialog() {
            if (pDialog.isShowing())
                pDialog.dismiss();
        }

    }

Login.php这是来自Android的转换后的json。

<?php
require_once 'include/DB_Functions.php';
$db = new DB_Functions();

// json response array
$response = array("error" => FALSE);

if (isset($_POST['email']) && isset($_POST['password'])) {

    // receiving the post params
    $email = $_POST['email'];
    $password = $_POST['password'];

    // get the user by email and password
    $user = $db->getUserByEmailAndPassword($email, $password);

    if ($user != false) {
        // use is found
        $response["error"] = FALSE;
        $response["uid"] = $user["unique_id"];
        $response["user"]["username"] = $user["username"];
        $response["user"]["name"] = $user["name"];
        $response["user"]["email"] = $user["email"];
        $response["user"]["created_at"] = $user["created_at"];
        $response["user"]["updated_at"] = $user["updated_at"];
        echo json_encode($response);
    } else {
        // user is not found with the credentials
        $response["error"] = TRUE;
        $response["error_msg"] = "Login credentials are wrong. Please try again!";
        echo json_encode($response);
    }
} else {
    // required post params is missing
    $response["error"] = TRUE;
    $response["error_msg"] = "Required parameters email or password is missing!";
    echo json_encode($response);
}
?>

AppConfig.java。这段代码用于连接。当我在＆＃34; IDHOSTINGER＆＃34;并在代码上更改此URL。这段代码不起作用。

    package com.sudotech.go_learn;

    public class AppConfig {
        // Server user login url
        public static String URL_LOGIN = "http://www.sudotech.pe.hu/login.php";

        // Server user register url
        public static String URL_REGISTER = "http://www.sudotech.pe.hu/register.php";

        // Server user register url
            public static String URL_REGISTERTEACHER = "

http://www.sudotech.pe.hu/registerteacher.php";

}

Answer 1

使用org.json库：使用此库，除非它不起作用

JsonObject object = new JSONObject(EscapedStringHere);

Answer 2

当我访问你的login.php链接时，它显示了这一点

我建议你做这些事情：

在 DB_Connect.php

mysql_connect（）

mysqli_connect（）

确保您的托管服务器已授予mysql用户访问权限
在 DB_Connect.php

mysql_select_db（）

mysqli_select_db（）

再次访问问题，请参阅第2点
尝试在 mysql_select_db（）之后添加 mysql_error（），就像这样

mysqli_select_db（＆＃39; your_database_name＆＃39;）或死亡（＆＃39;错误：＆＃39; .mysqli_error（））;

Answer 3

您使用的json StringRequest用于响应服务器字符串请求，

StringRequest strReq = new StringRequest(Method.POST,
                    AppConfig.URL_LOGIN, new Response.Listener<String>() {

}

将它用于Json对象请求的情况：

JSONObject jObj = new JSONObject（response）;

JsonObjectRequest strReq = new JsonObjectRequest(Method.POST,
                    AppConfig.URL_LOGIN, new Response.Listener<String>() {

}

额外：如果您使用JsonArrayRequest，则应使用：

 JsonArrayRequest strReq = new JsonArrayRequest(Method.POST,
                    AppConfig.URL_LOGIN, new Response.Listener<String>() {
}

在您的代码中使用

JSONObject jObj = new JSONObject(response);

所以我认为你应该使用JsonObjectRequest

在这里你可以得到详细信息:)

http://developer.android.com/training/volley/request.html#request-json

JSON无法在Android

3 个答案: