How to connect to PostgreSQL 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 PostgreSQL, Spring Boot can work with live PostgreSQL data. This article shows how to configure data sources and retrieve data in your Java Spring Boot Application, using the CData JDBC Driver for PostgreSQL.

With built-in optimized data processing, the CData JDBC Driver offers unmatched performance for interacting with live PostgreSQL data. When you issue complex SQL queries to PostgreSQL, the driver pushes supported SQL operations, like filters and aggregations, directly to PostgreSQL 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 PostgreSQL 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: 👁 Create a new 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.postgresql.jar</file>
					<groupId>org.cdata.connectors</groupId>
					<artifactId>cdata-postgresql-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-postgresql-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). 👁 Create a new Package in java folder
👁 Enter the name of the Package

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." 👁 Mark Directory as Sources 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. 👁 Create a new (configuration) file
👁 Name the file as application.properties

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

	spring.datasource.driver=cdata.jdbc.postgresql.PostgreSQLDriver
	spring.datasource.url=jdbc:postgresql:User=postgres;Password=admin;Database=postgres;Server=127.0.0.1;Port=5432;

Built-in Connection String Designer

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

java -jar cdata.jdbc.postgresql.jar

To connect to PostgreSQL, set the Server, Port (the default port is 5432), and Database connection properties and set the User and Password you wish to use to authenticate to the server. If the Database property is not specified, the data provider connects to the user's default database.

SSH Connectivity for PostgreSQL

You can use SSH (Secure Shell) to authenticate with PostgreSQL, whether the instance is hosted on-premises or in supported cloud environments. SSH authentication ensures that access is encrypted (as compared to direct network connections).

SSH Connections to PostgreSQL in Password Auth Mode

To connect to PostgreSQL via SSH in Password Auth mode, set the following connection properties:

• User: PostgreSQL User name
• Password: PostgreSQL Password
• Database: PostgreSQL database name
• Server: PostgreSQL Server name
• Port: PostgreSQL port number like 3306
• UserSSH: "true"
• SSHAuthMode: "Password"
• SSHPort: SSH Port number
• SSHServer: SSH Server name
• SSHUser: SSH User name
• SSHPassword: SSH Password

SSH Connections to PostgreSQL in Public Key Auth Mode

To connect to PostgreSQL via SSH in Password Auth mode, set the following connection properties:

• User: PostgreSQL User name
• Password: PostgreSQL Password
• Database: PostgreSQL database name
• Server: PostgreSQL Server name
• Port: PostgreSQL port number like 3306
• UserSSH: "true"
• SSHAuthMode: "Public_Key"
• SSHPort: SSH Port number
• SSHServer: SSH Server name
• SSHUser: SSH User name
• SSHClientCret: the path for the public key certificate file

👁 Using the built-in connection string designer to generate a JDBC URL (Salesforce is shown.)

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

Data Source Configuration

First, we mark the PostgreSQL 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. 👁 Create a 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 ="PostgreSQL")
	@Primary
	public static DataSource PostgreSQLDataSource()
	{

	DataSourceBuilder<?> dataSourceBuilder = DataSourceBuilder.create();
		dataSourceBuilder.driverClassName("cdata.jdbc.postgresql.PostgreSQLDriver");
		dataSourceBuilder.url("jdbc:postgresql:User=postgres;Password=admin;Database=postgres;Server=127.0.0.1;Port=5432;");
		return dataSourceBuilder.build();
	}
	
	//@Override
	public void setEnvironment( final Environment environment) {
	env=environment;
	}
}

Next, move the PostgreSQL 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: 👁 Execute Maven Goal
👁 Run Maven install command

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

After pressing enter, we see the following output: 👁 Successful installation of the JDBC driver

Testing the Connection

The last step is testing the connection. Create a new Java class following the format

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.PostgreSQLDataSource;


@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 = PostgreSQLDataSource().getConnection();
		System.out.println("Catalog: "+ conn.getCatalog());
	}
}

The output generated should look like this: 👁 Successful test connection

Free Trial & More Information

Download a free, 30-day trial of the CData JDBC Driver for PostgreSQL and start working with your live PostgreSQL in Spring Boot.