mysql - Android studio getSlotFromBufferLocked: unknown buffer error

Question

I want to make a simple login and register app, so the user can create an account. (name, username, password) I use WAMP and a MYSQL database where I store the accounts.

When I fill in the user info on the registration form and click register I get the following error:

09-14 09:30:39.864    2624-2638/com.example.appname.appname E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xab7115e0
09-14 09:30:48.632    2624-2638/com.example.appname.appname E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xab7125a0
09-14 09:30:51.940    2624-2638/com.example.appname.appname E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xab7125a0

When I go check the database it didn't store the account.

MainActivity.java

import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void userReg(View v)
    {
        startActivity(new Intent(this, Register.class));
    }
    public void userLogin(View view)
    {


    }


}

Register.java

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;

public class Register extends Activity {
    EditText ET_NAME,ET_USER_NAME,ET_USER_PASS;
    String name,user_name,user_pass;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.register_layout);
        ET_NAME = (EditText) findViewById(R.id.name);
        ET_USER_NAME = (EditText) findViewById(R.id.new_user_name);
        ET_USER_PASS = (EditText) findViewById(R.id.new_user_pass);
    }

    public void userReg(View view)
    {
        name = ET_NAME.getText().toString();
        user_name = ET_USER_NAME.getText().toString();
        user_pass = ET_USER_PASS.getText().toString();
        String method = "register";
        BackgroundTask backgroundTask = new BackgroundTask(Register.this);
        backgroundTask.execute(method,name,user_name,user_pass);
        finish();
    }
}

Backgroundtask.java

import android.app.AlertDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

public class BackgroundTask extends AsyncTask<String, Void, String> {
    AlertDialog alertDialog;
    Context ctx;

    BackgroundTask(Context ctx) {
        this.ctx = ctx;

    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params) {
        String reg_url = "http://10.0.2.2.2/webapp/register.php";
        String login_url = "http://10.0.2.2.2/webapp/login.php";
        String method = params[0];
        if (method.equals("register")) {
            String name = params[1];
            String user_name = params[2];
            String user_pass = params[3];
            try {
                URL url = new URL(reg_url);
                HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setDoOutput(true);
                OutputStream OS = httpURLConnection.getOutputStream();
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(OS, "UTF-8"));
                String data = URLEncoder.encode("user", "UTF-8") + "=" + URLEncoder.encode(name, "UTF-8") + "&" +
                        URLEncoder.encode("user_name", "UTF-8") + "=" + URLEncoder.encode(user_name, "UTF-8") + "&" +
                        URLEncoder.encode("user_pass", "UTF-8") + "=" + URLEncoder.encode(user_pass, "UTF-8");
                bufferedWriter.write(data);
                bufferedWriter.flush();
                bufferedWriter.close();
                OS.close();
                InputStream IS = httpURLConnection.getInputStream();
                IS.close();
                return "Registration Success...";
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return null;
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        super.onProgressUpdate(values);
    }

    @Override
    protected void onPostExecute(String result) {
        Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
    }
}

register.php

<?php
require "init.php";
$name = $_POST["user"];
$user_name = $_POST["user_name"];
$user_pass = $_POST["user_pass"];

$sql_query = "insert into user_info values('$name','$user_name','$user_pass');";

if(mysqli_query($con,$sql_query))
{
//echo"<h3> Data insertion success...</h3>";
}
else{
//echo "Data insertion error..".mysqli_error($con);
}



?>

init.php

<?php
$db_name="myDBname";
$mysql_user = "root";
$mysql_pass = "root";
$server_name="localhost";

$con = mysqli_connect($server_name,$mysql_user,$mysql_pass,$db_name);
if(!$con)
{
//echo"Connection Error".mysqli_connect_error();
}
else
{
//echo"<h3> Database connection success.....</h3>";
}


?>

Answer 1

Edit:

This was a bug in Android that was fixed in later versions of Marshmallow

Original:

I believe that this is Marshmallow specific. Are you using a Marshmallow device?

I've noticed this error is printed out every time I switch between applications (doesn't matter which) or exit out of them, and when activities are destroyed.

I've tried running the same apps on two Nexus 5s - one running Lollipop and the other Marshmallow, and these log prints only appeared on the Marshmallow version - with every app, not just the one I'm building.

Not sure why this happens, but I opened a report here.