Android登录注册中java.lang.String无法转换为JSONObject

Question

我在 java 中创建登录和注册时遇到问题。我能够创建一个用户，但它返回错误。它返回 JSON + 错误。 这是我尝试登录时的 JSON 和错误:

D/RegisterActivity: Login Response: login.php
                DB_Connect.php
                    Config.php
                {"error":false,"uid":"592da509e15a88.38765516","user":{"name":"P","email":"p","created_at":"2017-05-30 17:59:53"}}

W/System.err: org.json.JSONException: Value login.php of type java.lang.String cannot be converted to JSONObject
W/System.err:at activity.LoginActivity$3.onResponse(LoginActivity.java:125)
W/System.err:at activity.LoginActivity$3.onResponse(LoginActivity.java:117)

这是login.java

public class LoginActivity 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
public 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(LoginActivity.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(),
                    RegisterActivity.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 name = user.getString("name");
                    String email = user.getString("email");
                    String created_at = user
                            .getString("created_at");

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

                    // Launch main activity
                    Intent intent = new Intent(LoginActivity.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代码:

  <?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"]["name"] = $user["NAME"];
    $response["user"]["email"] = $user["email"];
    $response["user"]["created_at"] = $user["created_at"];
    echo json_encode($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);
}
?>

我花了几个小时在这上面，有人能指出我正确的方向吗？谢谢

Answer 1

Login Response: login.php DB_Connect.php Config.php {"error":false,"uid":"592da509e15a88.38765516","user":{"name‌​":"P","email":"p","c‌​reated_at":"2017-05-‌​30 17:59:53"}}

根据您附加的回复消息，它似乎完全错误。

您的响应不是 JSON 格式的字符串，这就是它无法从此响应字符串创建JSONObject的原因。

确保您的响应仅包含 JSONObject:

{"error":false,"uid":"592da509e15a88.38765516","user":{"name‌​":"P","email":"p","c‌​reated_at":"2017-05-‌​30 17:59:53"}}

从响应消息中删除不必要的字符串“login.php DB_Connect.php Config.php”。检查您的服务器端代码，为什么它添加字符串 "login.php DB_Connect.php Config.php" 和 JSONObject 。

我认为这会解决您的问题。