Hikari Connection Pool with Spring Boot mainly involves setting up a high-performance database connection pool for efficient management of the database connections within the application. When developing Spring Boot applications, the application will interact with databases, managing database connections with high performance and scalability. Without the connection pool, every request sent to the database will require establishing a new connection, which leads to a slow performance rate.

Hikari Connection Pool

Hikari connection pool is a popular, high-performance database connection pool for Java applications. HikariConnection Pool is very lightweight with low latency and scalability.

Benefits of Hikari Connection Pool

Below are the benefits of the Hikari Connection Pool.

• Improved Performance: Hikari connection pool is very much efficient in connection management which leads to better application performance under higher loads.
• Configuration Flexibility: In spring boot applications they provide the default configurations for HIkari Connection pool which we can customize the connection pool configuration as per the requirement.
• Simple Integration: With the spring boot auto-configuration feature, we can integrate the HikariConnection pool simply in to out application with minimal setup configurations.

Steps to Configure Hikari Connection in Spring Boot Application

Below are the steps to configure the Hikari Connection Pool in a Spring Boot application.

Step 1: Adding the dependency

To configure the Hikari connection, we need the com.zaxxer dependency, which we can get from Maven Repository. Below is the required dependency:

<dependency>
    <groupId>com.zaxxer</groupId>
    <artifactId>HikariCP</artifactId>
    <version>4.0.3</version> 
</dependency>

In the pom.xml file, add the above dependency.

Application.properties file Configuration

As we know, Spring Boot provides auto-configuration for the Hikari connection pool, which means we won’t need to make many configurations. However, we can customize the connection pool properties based on the application requirements. Here are the required configurations

After adding the configurations properties in the application.properties file, we will write the repository connection code as shown below:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

/**
 * RepositoryExample class represents an example repository component.
 */
@Repository
public class RepositoryExample {

    private final JdbcTemplate jdbcTemplate;

    /**
     * Constructs a new RepositoryExample instance with the provided JdbcTemplate.
     *
     * @param jdbcTemplate the JdbcTemplate to be used by this repository
     */
    @Autowired
    public RepositoryExample(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

}

In the code above, we inserted the @Autowired annotation into the repository class. This allows Spring Boot to automatically configure the JdbcTemplate bean with the HikariConnection pool specified in the application.properties file.