How to connect to Nuclia Data from Spring Boot

Spring Boot is a framework that makes engineering Java web applications easier. It offers the ability to create standalone applications with minimal configuration. When paired with the CData JDBC driver for Nuclia, Spring Boot can work with live Nuclia data. This article shows how to configure data sources and retrieve data in your Java Spring Boot Application, using the CData API Driver for JDBC.

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

Creating the Spring Boot Project in Java

In an IDE (in this tutorial, we use IntelliJ), choose a Maven project: In the generated project, go to the pom.xml file, and add the required dependencies for Spring Boot:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.2</version>
<relativePath/>
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<build>
<plugins>
	<plugin>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-maven-plugin</artifactId>
	</plugin>

	<plugin>
		<groupId>org.apache.maven.plugins</groupId>
		<artifactId>maven-install-plugin</artifactId>
		<version>2.5.1</version>
		<executions>
			<execution>
				<id>id.install-file</id>
				<phase>clean</phase>
				<goals>
					<goal>install-file</goal>
				</goals>
				<configuration>
					<file>C:\Program Files\CData[product_name] ####\lib\cdata.jdbc.api.jar</file>
					<groupId>org.cdata.connectors</groupId>
					<artifactId>cdata-api-connector</artifactId>
					<version>23</version>
					<packaging>jar</packaging>
				</configuration>
			</execution>
		</executions>
	</plugin>
</plugins>
</build>

<dependencies>
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-jdbc</artifactId>
	<version>2.7.0</version>
</dependency>
<dependency>
	<groupId>org.cdata.connectors</groupId>
	<artifactId>cdata-api-connector</artifactId>
	<version>23</version>
</dependency>

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-test</artifactId>
	<scope>test</scope>
</dependency>
</dependencies>



<distributionManagement>
<repository>
	<uniqueVersion>false</uniqueVersion>
	<id>test</id>
	<name>My Repository</name>
	<url>scp://repo/maven2</url>
	<layout>default</layout>
</repository>
</distributionManagement>

</project>

Note: The year (####) and the version number (as seen in the provided XML script) should be adjusted according to the current version of the CData JDBC driver being utilized.

Project Structure

In the java directory, create a new package. Usually the name of the package is the name of the groupId (com.example) followed by the artifactId (.MDS).

Mark the "java" directory as the "Sources Root" (denoted by a blue color). To do this, right-click the java directory and choose Mark Directory as -> Sources Root (As shown below). Additionally, mark the "resources" directory as the "Resources Root."

Store Database Connection Properties

Create an "application.properties" file to store the database connection properties. To do this, right-click on the "resources" folder, opt for New -> File, input the file name as "application.properties," and press Enter.

In the application.properties file, we set the configuration properties for the Nuclia JDBC Driver, using the Class name and JDBC URL:

	spring.datasource.driver=cdata.jdbc.api.APIDriver
	spring.datasource.url=jdbc:api:Profile=C:\profiles\Nuclia.apip;AuthScheme=APIKey;APIKey=your_service_account_key;KbId=your_kb_uuid;Zone=aws-us-east-2-1;

Built-in Connection String Designer

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

java -jar cdata.jdbc.api.jar

Using API Key Authentication

Nuclia uses API key authentication for accessing Knowledge Box data. To obtain an API key:

1. Log in to the Nuclia Cloud Dashboard at https://nuclia.cloud
2. Navigate to your Knowledge Box settings
3. Go to the Service Accounts section
4. Create a new service account or copy an existing API key

After obtaining your API key, set the following connection properties:

• AuthScheme: Set this to APIKey.
• APIKey: Set this to your Nuclia service account API key.
• KbId: Set this to your Knowledge Box UUID.
• Zone: Set this to your Nuclia deployment zone (e.g., aws-us-east-2-1).

Example Connection String

Profile=C:\profiles\Nuclia.apip;AuthScheme=APIKey;APIKey=your_service_account_key;KbId=your_kb_uuid;Zone=aws-us-east-2-1;

Connecting to Nuclia

Once the authentication is configured, you can connect to Nuclia and query data from any of the available tables such as Resources, KnowledgeBox, LabelSets, and ProcessingStatus.

After setting the properties in the application.properties file, we now configure them.

Data Source Configuration

First, we mark the Nuclia data source as our primary data source. Then, we create a Data Source Bean.

Create a DriverManagerDataSource.java file and create a Bean within it, as shown below. If @Bean gives an error, Spring Boot may not have loaded properly. To fix this, go to File -> Invalidate Caches and restart. Additionally, make sure that Maven has added the Spring Boot dependencies.

To create a data source bean, we use the DriverManagerDataSource Class. This class allows us to set the properties of the data source. To create this Java class, right-click on "com.example.MDS" package, and choose New -> Java Class.

The following code shows the bean definition of our data source. Each driver should have a bean.

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Primary;
import org.springframework.core.env.Environment;
import javax.sql.DataSource;

public class DriverManagerDataSource{
	@Autowired
	private static Environment env;

	@Bean(name ="API")
	@Primary
	public static DataSource APIDataSource()
	{

	DataSourceBuilder<?> dataSourceBuilder = DataSourceBuilder.create();
		dataSourceBuilder.driverClassName("cdata.jdbc.api.APIDriver");
		dataSourceBuilder.url("jdbc:api:Profile=C:\profiles\Nuclia.apip;AuthScheme=APIKey;APIKey=your_service_account_key;KbId=your_kb_uuid;Zone=aws-us-east-2-1;");
		return dataSourceBuilder.build();
	}
	
	//@Override
	public void setEnvironment( final Environment environment) {
	env=environment;
	}
}

Next, move the Nuclia jar file to the Documents folder (see path in command below) - The idea is to have a path without any spaces for the jar file. Then, click the Maven icon (top right corner of IntelliJ) and click "Execute Maven Goal." Now, run the following command:

mvn install:install-file "-Dfile=C:\Program Files\CData[product_name] ####\lib\cdata.jdbc.api.jar" -DgroupId=org.cdata.connectors -DartifactId=cdata-api-connector -Dversion=23 -Dpackaging=jar

Follow either of the given steps to run this command:

1. The "-Dfile location" can be kept as the default installation path of the CData JDBC Driver. Make sure to keep the path in quotations in this case. Also, change the year and "Dversion" based on the current version of the driver being used.
2. As mentioned earlier in the article, in case you relocate the jar file to the Documents folder, make sure to modify the path in the provided command. In such instances, avoid enclosing the Dfile location in quotations and edit "Dversion" based on the current version of the driver being used.

After pressing enter, we see the following output:

Testing the Connection

The last step is testing the connection. Create a new Java class following the format (e.g., "MDSApplication"). You have the flexibility to select any name for the application class. We call the data source in the main method of MDSApplication.java:

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import java.sql.Connection;
import java.sql.SQLException;
import static com.example.demo.DriverManagerDataSources.APIDataSource;


@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
	public class MDSApplication {
		//remove the comment on the line below
		public static void main (){
		SpringApplication.run(DemoApplication.class, args);
		Connection conn = APIDataSource().getConnection();
		System.out.println("Catalog: "+ conn.getCatalog());
	}
}

The output generated should look like this:

Free Trial & More Information

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