angular-8-spring-boot-postgresql-crud-example-feature-image

Angular 8 + Spring Boot + PostgreSQL example: a CRUD App

In this tutorial, we will learn how to build a full stack Angular 8 + Spring Boot + PostgreSQL example with a CRUD App. The back-end server uses Spring Boot with Spring Web MVC for REST Controller and Spring Data JPA for interacting with PostgreSQL database. Front-end side is made with Angular 8, HTTPClient & Router.

Newer version: Angular 10 + Spring Boot + PostgreSQL example: CRUD App

More Practice:
Angular 8 + Spring Boot: JWT Authentication with Spring Security example
Angular 8 + Spring Boot + MySQL example: CRUD App
Angular 8 + Spring Boot + MongoDB example: CRUD App
Angular 8 + Spring Boot: File upload example
Angular 8 + Spring Boot: Pagination example

Serverless:
Angular 8 Firebase CRUD Realtime DB | AngularFireDatabase


Angular 8, Spring Boot, PostgreSQL example

We will build a full-stack Tutorial CRUD Application in that:

  • Each Tutorial has id, title, description, published status.
  • We can create, retrieve, update, delete Tutorials.
  • We can also find Tutorials by title.

The images below shows screenshots of our System.

– Add Tutorial:

angular-8-spring-boot-postgresql-crud-example-create

– Retrieve all Tutorials:

angular-8-spring-boot-postgresql-crud-example-restrieve-all

– Click on Edit button to update a Tutorial:

angular-8-spring-boot-postgresql-crud-example-retrieve-one

On this Page, you can:

  • change status to Published using Publish button
  • delete the Tutorial using Delete button
  • update the Tutorial details with Update button

angular-8-spring-boot-postgresql-crud-example-update

– Search Tutorials by title:

angular-8-spring-boot-postgresql-crud-example-search

Angular 8 & Spring Boot Architecture

This is the application architecture we will build:

angular-8-spring-boot-postgresql-crud-example-architecture

– Spring Boot exports REST Apis using Spring Web MVC & interacts with PostgreSQL Database using Spring Data JPA.
– Angular Client sends HTTP Requests and retrieve HTTP Responses using axios, shows data on the components. We also use Angular Router for navigating to pages.

Spring Boot Back-end

Overview

These are APIs that Spring Boot App will export:

MethodsUrlsActions
POST/api/tutorialscreate new Tutorial
GET/api/tutorialsretrieve all Tutorials
GET/api/tutorials/:idretrieve a Tutorial by :id
PUT/api/tutorials/:idupdate a Tutorial by :id
DELETE/api/tutorials/:iddelete a Tutorial by :id
DELETE/api/tutorialsdelete all 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 8
  • Spring Boot 2 (with Spring Web MVC, Spring Data JPA)
  • PostgreSQL
  • Maven 3.6.1

Project Structure

angular-8-spring-boot-postgresql-crud-example-spring-server-project-structure

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.

Implementation

Create & Setup Spring Boot project

Use Spring web tool or your development tool (Spring Tool Suite, Eclipse, Intellij) to create a Spring Boot Maven project.

Then open pom.xml and add these dependencies:

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>

We also need to add one more dependency for PostgreSQL:

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

Configure Spring Datasource, JPA, Hibernate

Under src/main/resources folder, open application.properties and write these lines.

spring.datasource.url= jdbc:postgresql://localhost:5432/testdb
spring.datasource.username= postgres
spring.datasource.password= 123

spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation= true
spring.jpa.properties.hibernate.dialect= org.hibernate.dialect.PostgreSQLDialect

# Hibernate ddl auto (create, create-drop, validate, update)
spring.jpa.hibernate.ddl-auto= update
  • spring.datasource.username & spring.datasource.password properties are the same as your database installation.
  • Spring Boot uses Hibernate for JPA implementation, we configure PostgreSQLDialect for PostgreSQL
  • spring.jpa.hibernate.ddl-auto is used for database initialization. We set the value to update value so that a table will be created in the database automatically corresponding to defined data model. Any change to the model will also trigger an update to the table. For production, this property should be validate.

Define Data Model

Our Data model is Tutorial with four fields: id, title, description, published.
In model package, we define Tutorial class.

model/Tutorial.java

package com.bezkoder.spring.jpa.postgresql.model;

import javax.persistence.*;

@Entity
@Table(name = "tutorials")
public class Tutorial {

	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	private long id;

	@Column(name = "title")
	private String title;

	@Column(name = "description")
	private String description;

	@Column(name = "published")
	private boolean published;
	...
}

@Entity annotation indicates that the class is a persistent Java class.
@Table annotation provides the table that maps this entity.
@Id annotation is for the primary key.
@GeneratedValue annotation is used to define generation strategy for the primary key. GenerationType.AUTO means Auto Increment field.
@Column annotation is used to define the column in database that maps annotated field.

Create Repository Interface

Let’s create a repository to interact with Tutorials from the database.
In repository package, create TutorialRepository interface that extends JpaRepository.

repository/TutorialRepository.java

package com.bezkoder.spring.jpa.postgresql.repository;
...

public interface TutorialRepository extends JpaRepository<Tutorial, Long> {
  List<Tutorial> findByPublished(boolean published);

  List<Tutorial> findByTitleContaining(String title);
}

Now we can use JpaRepository’s methods: save(), findOne(), findById(), findAll(), count(), delete(), deleteById()… without implementing these methods.

We also define custom finder methods:
findByPublished(): returns all Tutorials with published having value as input published.
findByTitleContaining(): returns all Tutorials which title contains input title.

The implementation is plugged in by Spring Data JPA automatically.

You can modify this Repository:
– to work with Pagination, the instruction can be found at:
Spring Boot Pagination & Filter example | Spring JPA, Pageable
– or to sort/order by multiple fields with the tutorial:
Spring Data JPA Sort/Order by multiple Columns | Spring Boot

You also find way to write Unit Test for this JPA Repository at:
Spring Boot Unit Test for JPA Repositiory with @DataJpaTest

Create Spring Rest APIs Controller

Finally, we create a controller that provides APIs for creating, retrieving, updating, deleting and finding Tutorials.

controller/TutorialController.java

package com.bezkoder.spring.jpa.postgresql.controller;
...

@CrossOrigin(origins = "http://localhost:8081")
@RestController
@RequestMapping("/api")
public class TutorialController {

	@Autowired
	TutorialRepository tutorialRepository;

	@GetMapping("/tutorials")
	public ResponseEntity<List<Tutorial>> getAllTutorials(@RequestParam(required = false) String title) {
		...
	}

	@GetMapping("/tutorials/{id}")
	public ResponseEntity<Tutorial> getTutorialById(@PathVariable("id") long id) {
		...
	}

	@PostMapping("/tutorials")
	public ResponseEntity<Tutorial> createTutorial(@RequestBody Tutorial tutorial) {
		...
	}

	@PutMapping("/tutorials/{id}")
	public ResponseEntity<Tutorial> updateTutorial(@PathVariable("id") long id, @RequestBody Tutorial tutorial) {
		...
	}

	@DeleteMapping("/tutorials/{id}")
	public ResponseEntity<HttpStatus> deleteTutorial(@PathVariable("id") long id) {
		...
	}

	@DeleteMapping("/tutorials")
	public ResponseEntity<HttpStatus> deleteAllTutorials() {
		...
	}

	@GetMapping("/tutorials/published")
	public ResponseEntity<List<Tutorial>> findByPublished() {
		...
	}
}

@CrossOrigin is for configuring allowed origins.
@RestController annotation is used to define a controller and to indicate that the return value of the methods should be be bound to the web response body.
@RequestMapping("/api") declares that all Apis’ url in the controller will start with /api.
– We use @Autowired to inject TutorialRepository bean to local variable.

You can continue with step by step to implement this Spring Boot Server in the post:
Spring Boot, PostgreSQL: Build Rest CRUD Apis example with Maven & Spring JPA

Run Spring Boot Server

Run Spring Boot application with command: mvn spring-boot:run.

Angular 8 Front-end

Overview

angular-8-spring-boot-postgresql-crud-example-front-end-overview

– The App component is a container with router-outlet. It has navbar that links to routes paths via routerLink.

TutorialsList component gets and displays Tutorials.
Tutorial component has form for editing Tutorial’s details based on :id.
AddTutorial component has form for submission new Tutorial.

– These Components call TutorialService methods which use Angular HTTPClient to make HTTP requests and receive responses.

Technology

  • Angular 8
  • Angular HTTPClient
  • Angular Router

Project Structure

angular-8-spring-boot-postgresql-crud-example-angular-client-project-structure

– There are 3 components: tutorials-list, tutorial-details, add-tutorial.
tutorial.service has methods for sending HTTP requests to the Apis.
app-routing.module.ts defines routes for each component.
app component contains router view and navigation bar.
app.module.ts declares Angular components and import necessary modules.

Implementation

Setup Angular 8 Project

Let’s open cmd and use Angular CLI to create a new Angular Project as following command:

ng new Angular8ClientCrud
? Would you like to add Angular routing? Yes
? Which stylesheet format would you like to use? CSS

We also need to generate some Components and Services:

ng g s services/tutorial

ng g c components/add-tutorial
ng g c components/tutorial-details
ng g c components/tutorials-list

Now you can see that our project directory structure looks like this.

Set up App Module

Open app.module.ts and import FormsModule, HttpClientModule:

...
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';

@NgModule({
  declarations: [ ... ],
  imports: [
    ...
    FormsModule,
    HttpClientModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Define Routes for Angular AppRoutingModule

There are 3 main routes:
/tutorials for tutorials-list component
/tutorials/:id for tutorial-details component
/add for add-tutorial component

app-routing.module.ts

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { TutorialsListComponent } from './components/tutorials-list/tutorials-list.component';
import { TutorialDetailsComponent } from './components/tutorial-details/tutorial-details.component';
import { AddTutorialComponent } from './components/add-tutorial/add-tutorial.component';

const routes: Routes = [
  { path: '', redirectTo: 'tutorials', pathMatch: 'full' },
  { path: 'tutorials', component: TutorialsListComponent },
  { path: 'tutorials/:id', component: TutorialDetailsComponent },
  { path: 'add', component: AddTutorialComponent }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

Add Navbar and Router View to Angular CRUD App

Let’s open src/app.component.html, this App component is the root container for our application, it will contain a nav element.

<div>
  <nav class="navbar navbar-expand navbar-dark bg-dark">
    <a href="#" class="navbar-brand">bezKoder</a>
    <div class="navbar-nav mr-auto">
      <li class="nav-item">
        <a routerLink="tutorials" class="nav-link">Tutorials</a>
      </li>
      <li class="nav-item">
        <a routerLink="add" class="nav-link">Add</a>
      </li>
    </div>
  </nav>

  <div class="container mt-3">
    <router-outlet></router-outlet>
  </div>
</div>

Create Data Service

This service will use Angular HTTPClient to send HTTP requests.
You can see that its functions includes CRUD operations and finder method.

services/tutorial.service.ts

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';

const baseUrl = 'http://localhost:8080/api/tutorials';

@Injectable({
  providedIn: 'root'
})
export class TutorialService {

  constructor(private http: HttpClient) { }

  getAll() {
    return this.http.get(baseUrl);
  }

  get(id) {
    return this.http.get(`${baseUrl}/${id}`);
  }

  create(data) {
    return this.http.post(baseUrl, data);
  }

  update(id, data) {
    return this.http.put(`${baseUrl}/${id}`, data);
  }

  delete(id) {
    return this.http.delete(`${baseUrl}/${id}`);
  }

  deleteAll() {
    return this.http.delete(baseUrl);
  }

  findByTitle(title) {
    return this.http.get(`${baseUrl}?title=${title}`);
  }
}

Create Angular Components

As you’ve known before, there are 3 components corresponding to 3 routes defined in AppRoutingModule.

  • Add new Item Component
  • List of items Component
  • Item details Component

You can continue with step by step to implement this Angular App in the post:
Angular 8 CRUD Application example with Web API

Newer versions:
Angular 10 CRUD Application example with Web API
Angular 11 CRUD Application example with Web API

Run the Angular App

You can run this App with command: ng serve --port 8081.
If the process is successful, open Browser with Url: http://localhost:8081/ and check it.

Further Reading

Conclusion

Now we have an overview of Angular 8 + Spring Boot + PostgreSQL example when building a CRUD App.

We also take a look at client-server architecture for REST API using Spring Web MVC & Spring Data JPA, as well as Angular 8 project structure for building a front-end app to make HTTP requests and consume responses.

Next tutorials show you more details about how to implement the system:
Back-end
– Front-end:

You will want to know how to run both projects in one place:
How to Integrate Angular with Spring Boot Rest API

Pagination: Angular 8 + Spring Boot: Pagination example

Or Serverless:
Angular 8 Firebase CRUD Realtime DB | AngularFireDatabase

Happy learning, see you again!

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