Tuesday, September 29, 2020

MySql Export / Import Large Database


In this blog I am going to explain a trick which I recently used for Export / Import large database. 

Let me first explain the issue I faced. The database was over 250 MB. I was using MySql WorkBench to export in single self contained file. But it was breaking in between as some tables were really huge. 

So here is what I did. First in MySql WorkBench, in stead of exporting it to self contained single file, export it to Dump project folder. Here it will create sql file for each table in the folder. So in my case it created approximately 180 sql files. 

Now open terminal and go to that folder. First step here is we will concat all those files and make a single file.

Run the following command in terminal from folder where you have all the sql files.

cat *.sql  > .single_file.sql

Above command will concat all the files into one file and create that file in same folder. Now we will use this file to import into our database.

/Applications/MAMP/Library/bin/mysql -u DB_USER -p DB < .single_file.sql

That's it. With this trick you can Import / Export large database. Please note that, for this you should have terminal access to your MySql server.

Monday, September 7, 2020

Connect to Web Socket From Your Android App using OkHttp


In this blog I am going to explain how you can connect with Web Socket from your Android App using OkHttp. This will be useful when you want to send some data real time from your Android app to Web app. 

First add following line in your build.gradle file dependencies. 

implementation 'com.squareup.okhttp3:okhttp:3.11.0'

Now let the gradle build and sync. Next we will make a class which extends WebSocketListener from OkHttp3 and a new class and name it MyWebSocketListener.java and add following code to it. 

import okhttp3.Response;

import okhttp3.WebSocket;

import okhttp3.WebSocketListener;

import okio.ByteString;

public final class MyWebSocketListener extends WebSocketListener {

    private static final int NORMAL_CLOSURE_STATUS = 5000;

    public MyWebSocketListener() {  



    public void onOpen(WebSocket webSocket, Response response) {

        webSocket.close(NORMAL_CLOSURE_STATUS, "Exit");



    public void onMessage(WebSocket webSocket, String text) {

        //String Meesage received



    public void onMessage(WebSocket webSocket, ByteString bytes) {

        //Meesage received in form of binary data



    public void onClosing(WebSocket webSocket, int code, String reason) {

        webSocket.close(NORMAL_CLOSURE_STATUS, null);

        //Closing socket



    public void onFailure(WebSocket webSocket, Throwable t, Response response) {




Now we have listener created. Let's create client and attach it to Web Socket and Listener.

val listener = MyWebSocketListener()

val webSocket =   OkHttpClient.Builder().build().newWebSocket(request, listener)

That's it, now you can use this instance to send or receive message.

Saturday, September 5, 2020

Create Secure Web Socket (WSS) with Ratchet PHP


Recently I was working on PHP project where we I was create secure web socket which is accessible with wss:// protocol. For this I struggled for couple of hours so here in blog I am going to explain how to do that so it can save your time. 

Earlier version was not supporting WSS but later it introduced React socket server which allows SSL connection. So here are steps you need to follow. 

First add all the required classed in your php file.

use Ratchet\Server\IoServer;

use Ratchet\Http\HttpServer;

use Ratchet\WebSocket\WsServer;

use MyApp\Socket;

In above example Socket is my class file which has all listeners. After this add auto load file.

require dirname( __FILE__ ) . '/vendor/autoload.php';

Next we will create our socket app. 

$app = new \Ratchet\Http\HttpServer(
    new \Ratchet\WebSocket\WsServer(
        new \MyApp\Socket()

Now next step is to create React Secure server.

$loop = \React\EventLoop\Factory::create();
$webSock = new \React\Socket\Server('', $loop);

We are using  so this socket can be connected from anywhere. 

Now lets create secure server by adding path to certificate and key

$webSock = new \React\Socket\SecureServer($webSock, $loop, [
    'local_cert' => 'CRT_PATH', 
    'local_pk'=> 'KEY_PATH', 
    'allow_self_signed' => true, 
    'verify_peer' => false

Now finally we will run our server.

$webSock = new \Ratchet\Server\IoServer($app, $webSock, $loop);

That's it. It will start your server to which you can connect with WSS protocol. To test you can use WebSocket ECHO test.

Hope this helps you.