Personal Project

Monday, May 30, 2016

How to set up Master Slave replication for REST server using Spring framework ?


MYSQL replication architecture is vital for building high available REST API servers.
In order to avoid singe-point of failure problem, it`s recommended that setting 2 application servers and  Master-Slave database in MYSQL. Of course, you have to set up the application servers behind the load balancer.

The following details how to setup  REST API server by using Spring framework of Java.
How to set up MYSQL Master/Slave replication ?
// Edit
vim /src/main/resources/application.properties

## Master and Slave
spring.datasource.url = jdbc:mysql:replication://localhost1:3306,localhost2:3306/userdb 

The source codes of REST server can be seen here.

Wednesday, May 25, 2016

How to sniff packets for REST API on Ubuntu ?


Since the REST API is based on Http protocol, it is necessary to sniff the http header
and messages to assure that your applications function well.  The more you understand
how the Http messages work and communicate, the faster you can make your job done.

The command shown below might be useful for you to dump Http header and message while developing REST API on Ubuntu Linux. Its feature is as same as whireshark on Windows.


tcpdump -A -vvv -i [network card] port [ number]
 ex:
tcpdump -A -vvv -i eth0 port 8080


Thursday, May 12, 2016

How to validate Store Receipt for Apple Store and Google Play using Unity and PHP ?

Get Started

This tutorial will teach you how to validate Store receipt for Google Play and Apple Store using PHP and Unity.  You have to upload the PHP (verifyReceipt.php) to your server and set up the Unity plugin and add the following sample codes.

Import Unity Prime31 Plugin

Import Prime31 plugins StoreKit for Apple Store and In-App-Billing for Google Play into Unity.

How to setup In-App-Purchase for IOS ?

There are two steps for this.
  • Setup Item`s Product Id
  • Setup Payment Success Event to Get Receipt

Setup Item`s Product Id

Open a demo scene in folder
  /Plugins/Prime31/Storekit/demo/StoreKitTestScene.
Edit StoreKitGUIManager.cs and modify Product Id.
 /Plugins/Prime31/Storekit/demo/ StoreKitGUIManager.cs

 // XXXX is the product Id, which must match what you have in iTunes.
 var productIdentifiers = new string[] { "XXXX" };
 StoreKitBinding.requestProductData( productIdentifiers );

Setup Payment Success Event to Get Receipt

The following function aims to capture the receipt from Apple when the payment becomes successful, and send the receipt to PHP to validate the receipt`s correctness.
Edit /Plugins/Prime31/Storekit/demo/ StoreKitEventListener.cs

void purchaseSuccessfulEvent( StoreKitTransaction transaction )
   {
       Debug.Log( "purchaseSuccessfulEvent: " + transaction );

       // Get iOS receipt 
       string receipt = transaction.base64EncodedTransactionReceipt;

       // Build POST form
       WWWForm form = new WWWForm ();
       form.AddField ("key", "1234");
       form.AddField ("receipt", receipt);
       form.AddField ("en", "prod") // dev, prod
       form.AddField ("os", "ios")  // ios, android

       // Server URL
       string url = "http://your server IP/verifyPayment.php";

       // Process respond
       StartCoroutine(this.DoWWW(new WWW(url, form), (www) => {
           Debug.Log("-------- Callback Success: " + www.text);
       }));
   }

How to setup In-App-Billing for Android ?

There are two steps for this.
  • Setup App Public Key
  • Setup Item`s Product Id
  • Setup Payment Success Event to Get Receipt

Setup App Public Key

Open a demo scene in folder
/Plugins/ InAppBillingAndroid /demo/IABTestScene.unity
Setup Public key
Edit /Plugins/ InAppBillingAndroid /demo/ IABUIManager.cs

// Setup Public key 
var key = "Your Public Key on Google Play";

GoogleIAB.init( key );

Setup Item`s Product Id

Edit /Plugins/ InAppBillingAndroid /demo/ IABUIManager.cs

// Setup Product ID 
private string[] skus = new string[] 
{
    "XXXXXX"  //  your Product Id here 
};

GoogleIAB.queryInventory( skus );

Setup Payment Success Event to Get Receipt

Edit /Plugins/ InAppBillingAndroid /demo/ GoogleIABEventListener.cs


void purchaseCompleteAwaitingVerificationEvent( string purchaseData, string signature )
{
    Debug.Log( "purchaseCompleteAwaitingVerificationEvent. purchaseData: " + purchaseData + ", signature: " + signature );
    Prime31.Utils.logObject (purchaseData);
    Prime31.Utils.logObject (signature);

    // Google receipt 
    string receipt = purchaseData;

    // Initil POST form
    WWWForm form = new WWWForm ();
    form.AddField ("key", "1234");
    form.AddField ("os", "android");
    form.AddField ("en", "prod");
    form.AddField ("receipt", receipt);
    form.AddField ( "sing", signature);

    // Server URL
    string url = "http://your server ip/veryPayment.php";
    // Process respond
    StartCoroutine (this.DoWWW (new WWW (url, form), (www) => 
    {
        Debug.Log("-------- Callback Success: " + www.text);
    }));
}

Tuesday, May 10, 2016

How to develop a secure REST server with high performance using OAuth, HIBERNATE, and MYSQL in Spring framework ?

I found it difficult to develop a secure REST API Server from scratch with features like OAuth, MYSQL, HIBERNATE, MYSQL Token Store, JDBCTemplate, and HTTPS. It will take lots of time to put all the features together and make them work properly. 

In order to reduce redundant work, I therefore created the REST API server template in Spring framework. With this server template, you can focus on developing REST API to meet your needs without being distracted by other technologies.

Get Started

This project is a very simple REST and OAuth server template with high performance. Since the authenticated token is stored in MYSQL, its easy to scale up your server to meet high user traffic.

Project

This project includes the following features.
MVN
Spring-Boot
REST
JPA
MYSQL + HIBERNATE 
MYSQL Token Store
JDBCTemplate
Https

Setup MYSQL Database

Import userdb.sql into your database.
import database/userdb.sql into MYSQL database

Enable SSL

// Create key store 
bash
keytool -genkey -alias tomcat -keyalg RSA

// Edit 
vim /src/main/resources/application.properties

// Uncomment the following lines and set up your key store path
## SSL
server.port=8443
server.ssl.key-store=./src/main/resources/your.jks
server.ssl.key-store-password=your store passowrd
server.ssl.key-password=your pass

Building

You need Java (1.7 or better) and Maven (3.0.5 or better):
$ mvn clean package
$ mvn package
$ java -jar target/*.jar
...

// Http
<app starts and listens on port 8080>

// Https
<app starts and listens on port 8443>

Here are some curl commands to use to get started:
// Get Token
curl -k -X POST -d 'grant_type=client_credentials' --user 'my-client-with-secret:secret' https://localhost:8443/oauth/token
{"access_token":"bf12a9c8-c341-44a6-9ce6-084a8ba86652","token_type":"bearer","expires_in":43199,"scope":"read"}

// hasUserId GET
curl -k -H "Authorization: 5470484a-148d-479f-988e-89dfce617bb1" https://localhost:8443/user/hasUserId?uid=336u594534
{"status":200, "userId": 336u594534}

// Twitter Login POST
curl -k -H "Authorization: Bearer b61db2dd-0af4-4e3c-b2b9-7c307a9d7c69" -X POST -H "Content-Type: application/json" -d "{\"twitterId\": \"0926841831\", \"deviceId\": \"2222\"}" https://localhost:8443/user/twitterLogin

How to optimize MYSQL connection pool ?

// Edit
vim /src/main/resources/application.properties

// Configure initial and maximal connections 
spring.datasource.initialSize= 15
spring.datasource.maxActive= 30