Spring MVC + Spring Data + Apache Camel (Service Gateway Using Eureka)

In this demo you see how we can use Apache Camel alongside Eureka Service Discovery in order to implement a service gateway in a Spring MVC environment (Boot-less). You are able to map eureka services with custom context paths and relegate the requests come to camel, to the appropriate eureka service. So, basically you just know about camel and are able to send requests to it and in the back-end, camel relegate your request to the appropriate eureka-service and then return the response to you.

Libraries and Tools

• [Framework] Spring MVC
• [Integration Framework] Apache Camel which uses Spark Java for REST API
• [ORM] Hibernate under abstraction of Spring Data JPA
• [Database] Oracle on port 1521

Prerequisite

In order to test this demo you should already have the followings:

• An Oracle database connection and consequently changing database.properties for it. In addition you should update enums/Schema.java file with your schema name

• An Eureka server starting for registry/discovery of services. In this case you can use other repository of mine named service-gateway and just start config-server, eureka-server and account-service modules in order. This will start an Eureka server on localhost:8090 and registers a REST service named account-service on it. In case you want to change the Eureka port, you should update eureka.properties file with your own configs.

• Port 8089 should be open for camel REST API. You are able to configure it in application.properties file.

How to run

You need to run this demo on a tomcat server. For the rest of the article lets assume this demo is started on localhost:8082.

How it works

• To get all the services: Http.GET to http://localhost:8082/service-gateway/services
• To add a mapping for a pair of context path and eureka service: Http.POST to http://localhost:8082/service-gateway/services with the following json as request body:

{
    "contextPath": "accounts",
    "eurekaServiceName": "account-service",
    "eurekaServiceStatusEntity": {
        "id": 1,
        "eurekaServiceStatusType": "PUBLISHED",
        "description": "published status"
    },
    "subSystemCategoryEntity": {
        "id": 1,
        "subSystemCategoryType": "ARZI",
        "description": "arzi category"
    }
}

After adding the mapping of accounts context path for account-service eureka service, you are able to call camel with Http.GET on http://localhost:8089/services/accounts to get the list of accounts comes from account-service eureka service.