Spring Boot PostgreSQL Example

PostgreSQL is a powerful , open source relational database system. In this post we will see how to build REST API using Spring Boot with PostgreSQL database.

From the Spring initializr create a project with the below shown dependencies

To configure Spring Boot to use postgreSQL:

spring.datasource.url=jdbc:postgresql://localhost:5432/School
spring.datasource.username=${USERNAME}
spring.datasource.password=${PASSWORD}
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.PostgreSQLDialect
spring.jpa.hibernate.ddl-auto = update

Entity:

package com.example.postgresdemo.entity;

import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Entity
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student {
 
 @Id
 private int rollNumber;
 
 private String name;
 
 private int age;
}

Let’s create StudentRepository

public interface StudentRepository extends JpaRepository<Student, Integer>{

}

Defined below API’s

1. Add a Student
2. Get all Students

@RestController
public class PostgresdemoController {
 
 @Autowired
 StudentService service;
 
 @PostMapping("/Student")
 public Student add(@RequestBody Student student) {
  return service.addStudent(student);
  
 }
 
 @GetMapping("/Student")
 public List<Student> getAll() {
  return service.getAllStudents();
  
 }

}

Service layer:

@Service
public class StudentServiceImpl implements StudentService{
 
 @Autowired
 StudentRepository repository;

 public Student addStudent(Student student) {
  return repository.save(student);
 }

 @Override
 public List<Student> getAllStudents() {
  return repository.findAll();
 }
}

Added couple of students using add API through postman. Presented below the table view from postgreSQL database.

Source Code: https://github.com/MMahendravarman/Springboot_Examples