To connect a PostgreSQL database in a Spring Boot application, follow these steps:


1. Add PostgreSQL Driver Dependency

For Maven:

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    
</dependency>

For Gradle:

implementation 'org.postgresql:postgresql:42.7.1'

2. Configure application.properties or application.yml

Option A: application.properties

spring.datasource.url=jdbc:postgresql://localhost:5432/devdb
spring.datasource.username=postgres
spring.datasource.password=postgres
spring.datasource.driver-class-name=org.postgresql.Driver
 
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect

3. Test the Connection

  • Start your Docker container with Postgres running.

  • Launch the Spring Boot app.

  • Look for this log line:

    HHH000400: Using dialect: org.hibernate.dialect.PostgreSQLDialect
    
  • If there’s a connection issue, Spring Boot will throw an exception on startup.


Let me know if you want to use connection pooling (e.g. HikariCP, which is default), Flyway/Liquibase migrations, or Spring Data JPA.