Tien Nguyen

Posted on May 13, 2021 Edited on Jun 2, 2023

Spring Boot + PostgreSQL + Maven: CRUD example

#spring #postgres #java #webdev

In this tutorial, we're gonna build a Spring Boot + PostgreSQL example with Maven that uses Spring Data JPA/Hibernate to interact with PostgreSQL database and export Rest CRUD API. You'll know:

How to configure Spring Data, JPA, Hibernate to work with PostgreSQL Database
How to define Data Models and Repository interfaces
Way to create Spring Rest Controller to process HTTP requests
Way to use Spring Data JPA to interact with PostgreSQL Database

Full Article: Spring Boot + PostgreSQL + Maven: CRUD example

Overview of Spring Boot, PostgreSQL example with Maven

We will build a Spring Boot + PostgreSQL + Rest CRUD API for a Tutorial application in that:

Each Tutotial has id, title, description, published status.
Apis help to create, retrieve, update, delete Tutorials.
Apis also support custom finder methods such as find by published status or by title.

These are APIs that we need to provide:

Methods	Urls	Actions
POST	/api/tutorials	create new Tutorial
GET	/api/tutorials	retrieve all Tutorials
GET	/api/tutorials/:id	retrieve a Tutorial by `:id`
PUT	/api/tutorials/:id	update a Tutorial by `:id`
DELETE	/api/tutorials/:id	delete a Tutorial by `:id`
DELETE	/api/tutorials	delete all Tutorials
GET	/api/tutorials/published	find all published Tutorials
GET	/api/tutorials?title=[keyword]	find all Tutorials which title contains `keyword`

We make CRUD operations & finder methods with Spring Data JPA's JpaRepository.
The database will be PostgreSQL by configuring project dependency & datasource.

Technology

Java 17 / 11 / 8
Spring Boot 3 / 2 (with Spring Web MVC, Spring Data JPA)
PostgreSQL
Maven

Maven Project Structure

Let me explain it briefly.

– Tutorial data model class corresponds to entity and table tutorials.
– TutorialRepository is an interface that extends JpaRepository for CRUD methods and custom finder methods. It will be autowired in TutorialController.
– TutorialController is a RestController which has request mapping methods for RESTful requests such as: getAllTutorials, createTutorial, updateTutorial, deleteTutorial, findByPublished...
– Configuration for Spring Datasource, JPA & Hibernate in application.properties.
– pom.xml contains dependencies for Spring Boot and PostgreSQL.

Run the Application

Run Spring Boot + PostgreSQL application with Maven: mvn spring-boot:run.

tutorials table will be automatically generated in Database.
If you check PostgreSQL for example, you can see things like this:



testdb=# \d tutorials
             Table "public.tutorials"
   Column    |          Type          | Modifiers
-------------+------------------------+-----------
 id          | bigint                 | not null
 description | character varying(255) |
 published   | boolean                |
 title       | character varying(255) |
Indexes:
    "tutorials_pkey" PRIMARY KEY, btree (id)

Create some Tutorials:



testdb=# SELECT * FROM tutorials;
 id |    description    | published |            title
----+-------------------+-----------+------------------------------
  1 | Tut#1 Description | f         | Spring Boot Tut#1
  2 | Tut#2 Description | f         | PostgreSQL Tut#2
  3 | Tut#3 Description | f         | Spring Data JPA Tut#3
  4 | Tut#4 Description | f         | Maven Tut#4
  5 | Tut#5 Description | f         | Spring Boot PostgreSQL Tut#5
(5 rows)

Update some Tutorials:



testdb=# SELECT * FROM tutorials;
 id |    description    | published |            title
----+-------------------+-----------+------------------------------
  3 | Tut#3 Description | f         | Spring Data JPA Tut#3
  5 | Tut#5 Description | f         | Spring Boot PostgreSQL Tut#5
  2 | Desc for Tut#2    | t         | PostgreSQL DB Tut#2
  4 | Desc for Tut#4    | t         | Maven Tut#4
  1 | Desc for Tut#1    | t         | Spring Boot Tut#1
(5 rows)

Retrieve all Tutorials:

Get a Tutorial by Id:

Find all published Tutorials:

Find all Tutorials which title contains 'ring':

Delete a Tutorial:



testdb=# SELECT * FROM tutorials;
 id |    description    | published |            title
----+-------------------+-----------+------------------------------
  3 | Tut#3 Description | f         | Spring Data JPA Tut#3
  5 | Tut#5 Description | f         | Spring Boot PostgreSQL Tut#5
  2 | Desc for Tut#2    | t         | PostgreSQL DB Tut#2
  1 | Desc for Tut#1    | t         | Spring Boot Tut#1
(4 rows)

Delete all Tutorials:



testdb=# SELECT * FROM tutorials;
 id | description | published | title
----+-------------+-----------+-------
(0 rows)

Source code

For step by step instruction and Github, please visit:
Full Article: Spring Boot + PostgreSQL + Maven: CRUD example

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