Java 无法在我的Android应用程序中验证登录凭据

我正在创建一个基本的登录和注册android应用程序。我被困在一个地方，我想用DB验证我的用户输入的凭证，并相应地允许用户登录，这是这样一个系统的默认流程。但问题是，即使条目与数据库不匹配，我的应用程序也会将我带到下一个活动

我使用PHP/MySQL进行后端数据库连接

参考文件：-

我希望用户在输入错误的凭据时收到错误消息，从而试图阻止用户进入下一个活动，但在输入错误凭据的情况下，它会进入另一个活动

编辑1：- 这些是我的PHP文件

 **db_connect.php :-**

    <?php
$db_name = "ldsandroidapp";
$mysql_username = "root";
$mysql_password = "root@123";
$server_name = "localhost";
$conn =  mysqli_connect($server_name, $mysql_username, $mysql_password, $db_name);
if ($conn) {
    echo "Connection successfull";
}
else {
    echo "Connection unsuccessfull";
}

?>


    **login.php :-**

    <?php
require "db_connect.php";

$user_name = $_POST["full_name"];
$user_pass = $_POST["password"];
$mysql_qry = "select * from register where full_name ='$user_name' and password ='$user_pass'";
$result = mysqli_query($conn, $mysql_qry);
if(mysqli_num_rows($result) > 0) 
{
    $row = mysqli_fetch_assoc($result);
    $name = $row["full_name"];
    $psw = $row["password"];
    echo "success";
}
else 
{
    echo "error";
}




?>


**register.php :-**

<?php
require "db_connect.php";

$user_name = $_POST["full_name"];
$employee_id = $_POST["employee_id"];
$user_pass = $_POST["password"];
$mysql_qry = "insert into register (full_name, employee_id, password) values ('$user_name', '$employee_id', '$user_pass')";

    if(mysqli_query($conn, $mysql_qry))
    {
        echo "done";
    }
    else
    {
        echo "error";
    }


?>

**db_connect.php：-**
**login.php：-**
你的PHP代码在哪里？你确定你的PHP逻辑是正确的吗？@Dharman-是的，我的PHP逻辑是正确的，因为我尝试创建了一个虚拟HTML表单来检查注册和登录是否正常。我仍然会附上相应的PHP文件以供参考
    public class MainActivity extends AppCompatActivity {

    EditText et1,et2;
    TextView tv_frg_psw;
    Button btn,btn_register;
    String fullname, password;
    String finalResult ;
    String HttpURL = "http://mydomainip/folder1/login.php";
    Cursor cursor;


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


        et1 = (EditText)findViewById(R.id.eteid);
        et2 = (EditText)findViewById(R.id.etpsw);
        btn = (Button)findViewById(R.id.btnlogin);
        tv_frg_psw = (TextView)findViewById(R.id.tv_frg_psw);
        btn_register = (Button)findViewById(R.id.btn_register);

       btn.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View view) {

               String full_name=et1.getText().toString();
               String password=et2.getText().toString();

               String type = "login";
               BackgroundWorker backgroundWorker = new BackgroundWorker(MainActivity.this);
               backgroundWorker.execute(type, full_name, password);

             }
       });

       btn_register.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View view) {
               Intent i = new Intent(MainActivity.this,RegistrationActivity.class);
               startActivity(i);
           }
       });

    }


public void perform_action(View v)
    {
        Intent i = new Intent(MainActivity.this,ForgotPasswordActivity.class);
        startActivity(i);
    }

    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        switch(id) {
            case R.id.item1:
                Intent adminlogin = new Intent(MainActivity.this,AdminLogin.class);
                startActivity(adminlogin);
                //Toast.makeText(getApplicationContext(), "Item 1 Selected", Toast.LENGTH_LONG).show();
                return true;
            default:
                return super.onOptionsItemSelected(item);

        }
  }
}

 **db_connect.php :-**

    <?php
$db_name = "ldsandroidapp";
$mysql_username = "root";
$mysql_password = "root@123";
$server_name = "localhost";
$conn =  mysqli_connect($server_name, $mysql_username, $mysql_password, $db_name);
if ($conn) {
    echo "Connection successfull";
}
else {
    echo "Connection unsuccessfull";
}

?>


    **login.php :-**

    <?php
require "db_connect.php";

$user_name = $_POST["full_name"];
$user_pass = $_POST["password"];
$mysql_qry = "select * from register where full_name ='$user_name' and password ='$user_pass'";
$result = mysqli_query($conn, $mysql_qry);
if(mysqli_num_rows($result) > 0) 
{
    $row = mysqli_fetch_assoc($result);
    $name = $row["full_name"];
    $psw = $row["password"];
    echo "success";
}
else 
{
    echo "error";
}




?>


**register.php :-**

<?php
require "db_connect.php";

$user_name = $_POST["full_name"];
$employee_id = $_POST["employee_id"];
$user_pass = $_POST["password"];
$mysql_qry = "insert into register (full_name, employee_id, password) values ('$user_name', '$employee_id', '$user_pass')";

    if(mysqli_query($conn, $mysql_qry))
    {
        echo "done";
    }
    else
    {
        echo "error";
    }


?>