Integrate with RabbitMQ Data using Apache Camel2

Apache Camel is an open source integration framework that allows you to integrate various systems consuming or producing data. When paired with the CData API Driver for JDBC, you can write Java apps that use Camel routes that integrate with live RabbitMQ data. This article explains how to create an app in NetBeans that connects, queries, and routes RabbitMQ data to a JSON file.

With built-in optimized data processing, the CData JDBC Driver offers unmatched performance for interacting with live RabbitMQ data. When you issue complex SQL queries to RabbitMQ, the driver pushes supported SQL operations, like filters and aggregations, directly to RabbitMQ and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations). Its built-in dynamic metadata querying allows you to work with and analyze RabbitMQ data using native data types.

Creating A New Maven/Java Project

Follow the steps below to create a new Java project and add the appropriate dependencies:

1. Open NetBeans and create a new project.
2. Select Maven from the categories list and Java Application from the projects list, then click Next.
3. Name the project (and adjust any other properties) and click Finish.
4. In the source package, create a new Java class (we used App.java for this article) and add the main method to the class.

Adding Project Dependencies

With the project created, we can start adding the dependencies needed to work with live RabbitMQ data from our App. If you have not already done so, install Maven in your environment, as it is required to add the JAR file for the CData JDBC Driver to your project.

Installing the CData API Driver for JDBC with Maven

1. Download the CData API Driver for JDBC installer, unzip the package, and run the JAR file to install the driver.
2. Use Maven to install the JDBC Driver as a connector.

   mvn install:install-file 
   	-Dfile="C:\Program Files\CData[product_name] 2019\lib\cdata.jdbc.api.jar" 
   	-DgroupId="org.cdata.connectors" 
   	-DartifactId="cdata-api-connector" 
   	-Dversion="19" 
   	-Dpackaging=jar
   

Once the JDBC Driver is installed, we can add dependencies to our project. To add a dependency, you can either edit the pom.xml file or right-click the dependencies folder and click Add Dependency. The properties for each dependency follow, but you can search through the available libraries by typing the name of the dependency in the Query box in the Add Dependency wizard.

Required Dependencies

Accessing RabbitMQ Data in Java Apps with Camel

After adding the required dependencies, we can use the Java DSL (Domain Specific Language) to create routes with access to live RabbitMQ data. Code snippets follow. Download the sample project (zip file) to follow along (make note of the TODO comments).

Start by importing the necessary classes into our main class.

import org.apache.camel.CamelContext;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.impl.DefaultCamelContext;
import org.apache.camel.support.SimpleRegistry;
import org.apache.commons.dbcp2.BasicDataSource;
import org.apache.log4j.BasicConfigurator;

Then in the main method, we configure logging, create a new BasicDataSource and add it to the registry, create a new CamelContext, and finally add a route to the context. In this sample, we route RabbitMQ data to a JSON file.

Configure Logging

BasicConfigurator.configure();

Create a BasicDataSource

Create a BasicDataSource and set the driver class name (cdata.jdbc.salesforce.SalesforceDriver) and URL (using the required connection properties).

About RabbitMQ Management HTTP API

RabbitMQ is an open-source message broker that supports multiple messaging protocols. The RabbitMQ Management HTTP API provides HTTP-based access to management and monitoring data for a RabbitMQ server. The API exposes information about virtual hosts, exchanges, queues, bindings, connections, channels, consumers, users, permissions, policies, and cluster-wide statistics.

The Management plugin must be enabled on the RabbitMQ server for the HTTP API to be available. By default, the management interface listens on port 15672.

Using Basic Authentication

RabbitMQ Management HTTP API uses HTTP Basic authentication. You must supply the username and password of a RabbitMQ management user.

To enable access to the management API:

1. Ensure the RabbitMQ Management plugin is enabled on your server (rabbitmq-plugins enable rabbitmq_management).
2. Use an existing management user or create one with the appropriate management tag (management, policymaker, monitoring, or administrator).
3. Note the full base URL of your RabbitMQ Management HTTP API (e.g., http://localhost:15672).

After configuring your RabbitMQ server, set the following connection properties to connect:

• AuthScheme: Set this to Basic.
• URL: Set this to the base URL of your RabbitMQ Management HTTP API (e.g., http://localhost:15672).
• User: Set this to your RabbitMQ management username (e.g., guest).
• Password: Set this to your RabbitMQ management password.

Example connection string:

Profile=C:\profiles\RabbitMQ.apip;AuthScheme=Basic;URL=http://localhost:15672;User=guest;Password=guest;

Available Tables

The RabbitMQ profile provides access to the following tables:

• Overview - Cluster-wide statistics and information about the RabbitMQ node
• Nodes - Information about individual nodes in the RabbitMQ cluster
• NodeMemory - Detailed memory usage breakdown for a specific cluster node
• Connections - List of all open AMQP connections to the broker
• Channels - List of all open AMQP channels across all connections
• Consumers - List of all consumers registered across all queues
• Exchanges - List of exchanges declared across all virtual hosts
• Queues - List of queues declared across all virtual hosts
• Bindings - List of all bindings between exchanges and queues
• VirtualHosts - List of virtual hosts configured on the broker
• VhostPermissions - User permissions within a specific virtual host
• Users - List of all RabbitMQ users
• Permissions - Permission records for all users across all virtual hosts
• TopicPermissions - Topic-level permission records for all users
• Policies - List of policies applied to queues and exchanges in virtual hosts
• OperatorPolicies - List of operator policies applied to queues in virtual hosts
• Parameters - List of component parameters (e.g., federation, shovel) per virtual host
• GlobalParameters - List of global parameters that apply across all virtual hosts
• VhostLimits - Resource limits configured for specific virtual hosts
• UserLimits - Resource limits configured for specific users
• FeatureFlags - List of feature flags and their enabled/disabled state on the node
• DeprecatedFeatures - List of deprecated features and their usage state
• AuthAttempts - Authentication attempt statistics for the node
• ClusterName - The name of the RabbitMQ cluster
• WhoAmI - Information about the currently authenticated management user
• ExchangeBindingsSource - Bindings for which a specific exchange is the source
• ExchangeBindingsDestination - Bindings for which a specific exchange is the destination
• QueueBindings - Bindings for a specific queue within a virtual host

BasicDataSource basic = new BasicDataSource();
basic.setDriverClassName("cdata.jdbc.api.APIDriver");
basic.setUrl("jdbc:api:Profile=C:\profiles\\RabbitMQ.apip;AuthScheme=Basic;URL=http://localhost:15672;User=guest;Password=guest;");

The CData JDBC Driver includes a built-in connection string designer to help you configure the connection URL.

Built-in Connection String Designer

For assistance in constructing the JDBC URL, use the connection string designer built into the RabbitMQ JDBC Driver. Either double-click the JAR file or execute the jar file from the command line.

java -jar cdata.jdbc.api.jar

Fill in the connection properties and copy the connection string to the clipboard.

Add the BasicDataSource to the Registry and Create a CamelContext

SimpleRegistry reg = new SimpleRegistry();
reg.bind("myDataSource", basic);

CamelContext context = new DefaultCamelContext(reg);

Add Routing to the CamelContext

The routing below uses a timer component to run one time and passes a SQL query to the JDBC Driver. The results are marshaled as JSON (and formatted for pretty print) and passed to a file component to write to disk as a JSON file.

context.addRoutes(new RouteBuilder() {
	@Override
	public void configure() {
		from("timer://foo?repeatCount=1")
			.setBody(constant("SELECT * FROM Account LIMIT 10"))
			.to("jdbc:myDataSource")
			.marshal().json(true)
			.to("file:C:\\Users\\USER\\Documents?fileName=account.json");
	}
});

Managing the CamelContext Lifecycle

With the route defined, start the CamelContext to begin the lifecycle. In this example, we wait 10 seconds and then shut down the context.

context.start();
Thread.sleep(10000);
context.stop();

Free Trial, Sample Project & Technical Support

Now, you have a working Java application that uses Camel to route data from RabbitMQ to a JSON file. Download a free, 30-day trial of the CData API Driver for JDBC and the sample project (make note of the TODO comments) and start working with your live RabbitMQ data in Apache Camel. Reach out to our Support Team if you have any questions.