Integrate with AlloyDB 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 JDBC Driver for AlloyDB, you can write Java apps that use Camel routes that integrate with live AlloyDB data. This article walks through creating an app in NetBeans that connects, queries, and routes AlloyDB data to a JSON file.

With built-in optimized data processing, the CData JDBC Driver offers unmatched performance for interacting with live AlloyDB data. When you issue complex SQL queries to AlloyDB, the driver pushes supported SQL operations, like filters and aggregations, directly to AlloyDB 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 AlloyDB 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 AlloyDB 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 JDBC Driver for AlloyDB with Maven

1. Download the CData JDBC Driver for AlloyDB 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.alloydb.jar" 
   	-DgroupId="org.cdata.connectors" 
   	-DartifactId="cdata-alloydb-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 AlloyDB 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 AlloyDB 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 AlloyDB 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).

The following connection properties are usually required in order to connect to AlloyDB.

• Server: The host name or IP of the server hosting the AlloyDB database.
• User: The user which will be used to authenticate with the AlloyDB server.
• Password: The password which will be used to authenticate with the AlloyDB server.

You can also optionally set the following:

• Database: The database to connect to when connecting to the AlloyDB Server. If this is not set, the user's default database will be used.
• Port: The port of the server hosting the AlloyDB database. This property is set to 5432 by default.

Authenticating with Standard Authentication

Standard authentication (using the user/password combination supplied earlier) is the default form of authentication.

No further action is required to leverage Standard Authentication to connect.

Authenticating with pg_hba.conf Auth Schemes

There are additional methods of authentication available which must be enabled in the pg_hba.conf file on the AlloyDB server.

Find instructions about authentication setup on the AlloyDB Server here.

Authenticating with MD5 Authentication

This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to md5.

Authenticating with SASL Authentication

This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to scram-sha-256.

Authenticating with Kerberos

The authentication with Kerberos is initiated by AlloyDB Server when the ∏ is trying to connect to it. You should set up Kerberos on the AlloyDB Server to activate this authentication method. Once you have Kerberos authentication set up on the AlloyDB Server, see the Kerberos section of the help documentation for details on how to authenticate with Kerberos.

BasicDataSource basic = new BasicDataSource();
basic.setDriverClassName("cdata.jdbc.alloydb.AlloyDBDriver");
basic.setUrl("jdbc:alloydb:User=alloydb;Password=admin;Database=alloydb;Server=127.0.0.1;Port=5432");

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 AlloyDB JDBC Driver. Either double-click the JAR file or execute the jar file from the command line.

java -jar cdata.jdbc.alloydb.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 AlloyDB to a JSON file. Download a free, 30-day trial of the CData JDBC Driver for AlloyDB and the sample project (make note of the TODO comments) and start working with your live AlloyDB data in Apache Camel. Reach out to our Support Team if you have any questions.