Angular 12 + Spring Boot: CRUD example

In this tutorial, we will learn how to build a full stack Spring Boot + Angular 12 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 embedded database (H2 database). Front-end side is made with Angular 12, HttpClient, Router and Bootstrap 4.

Run both Project on same server/port:
How to Integrate Angular with Spring Boot Rest API

Security: Angular 12 + Spring Boot: JWT Authentication & Authorization example

Upload: Angular 12 + Spring Boot: File upload example

Pagination: Angular 12 + Spring Boot: Pagination example


Angular Spring Boot CRUD example

We will build a full-stack Angular 12 + Spring Boot 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-12-spring-boot-crud-example-create-tutorial

– Show all Tutorials:

angular-12-spring-boot-crud-example-retrieve-all-tutorial

– Click on Edit button to update a Tutorial:

angular-12-spring-boot-crud-example-retrieve-one-tutorial

On this Page, you can:

  • change status to Published using Publish button
  • remove the Tutorial from Database using Delete button
  • update the Tutorial details on Database with Update button

angular-12-spring-boot-crud-example-update-tutorial

If you want to implement Form Validation, please visit:
Angular 12 Form Validation example (Reactive Forms)

– Search Tutorials by title:

angular-12-spring-boot-crud-example-search-tutorial

Angular 12 + Spring Boot CRUD Architecture

Now look at the application architecture we will build:

angular-12-spring-boot-crud-example-architecture

– Spring Boot exports REST Apis using Spring Web MVC & interacts with embedded H2 Database using Spring Data JPA.
– Angular 12 Client sends HTTP Requests and retrieve HTTP Responses using HttpClient Module, shows data on the components. We also use Angular Router for navigating to pages.

You can also find the Spring Restful Apis that works with other databases here:
Spring JPA + PostgreSQL
Spring JPA + MySQL
Spring Data + MongoDB
Spring JPA + Oracle
Spring Data + Cassandra

Video

This is our Angular + Spring Boot CRUD application demo and brief instruction, running with MySQL database:

In the video, we use Angular 10, but the logic and UI are the same as this Angular version 12.

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 H2 Database (in memory or on disk) by configuring project dependency & datasource.

Technology

  • Java 8
  • Spring Boot 2.2.1 (with Spring Web MVC, Spring Data JPA)
  • H2 Database
  • Maven 3.6.1

Project Structure

angular-12-spring-boot-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 H2 Database.

Create & Setup Spring Boot project

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

<dependency>
	<groupId>com.h2database</groupId>
	<artifactId>h2</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:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
 
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.H2Dialect
spring.jpa.hibernate.ddl-auto= update

spring.h2.console.enabled=true
# default path: h2-console
spring.h2.console.path=/h2-ui
  • spring.datasource.url: jdbc:h2:mem for In-memory database and jdbc:h2:file for disk-based database.
  • spring.datasource.username & spring.datasource.password properties are the same as your database installation.
  • Spring Boot uses Hibernate for JPA implementation, we configure H2Dialect for H2 Database
  • 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.
  • spring.h2.console.enabled=true tells the Spring to start H2 Database administration tool and you can access this tool on the browser: http://localhost:8080/h2-console.
  • spring.h2.console.path=/h2-ui is for H2 consol’’s url, so the default url http://localhost:8080/h2-console will change to http://localhost:8080/h2-ui.

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.datajpa.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;

	public Tutorial() {

	}

	...
}

@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.datajpa.repository;

import java.util.List;

import org.springframework.data.jpa.repository.JpaRepository;

import com.bezkoder.spring.datajpa.model.Tutorial;

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.datajpa.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 one of the posts:
Spring Boot JPA + H2
Spring Boot JPA + MySQL
Spring Boot JPA + PostgreSQL

Run the Spring Boot Server

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

Angular 12 Front-end

Overview

angular-12-spring-boot-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.
TutorialDetails 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 12
  • Angular HttpClient
  • Angular Router
  • Bootstrap 4

Project Structure

angular-12-spring-boot-crud-example-angular-client-project-structure

tutorial.model.ts exports the main class model: Tutorial.
– 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.

Setup Angular 12 Project

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

ng new Angular12Crud
? 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

ng g class models/tutorial --type=model

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 { RouterModule, Routes } 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 { }

Define Model Class

Our main model class Tutorial will be exported in tutorial.model.ts with 4 fields:

  • id
  • title
  • description
  • published

models/tutorial.model.ts

export class Tutorial {
  id?: any;
  title?: string;
  description?: string;
  published?: boolean;
}

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';
import { Observable } from 'rxjs';
import { Tutorial } from '../models/tutorial.model';

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

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

  constructor(private http: HttpClient) { }

  getAll(): Observable<Tutorial[]> {
    return this.http.get<Tutorial[]>(baseUrl);
  }

  get(id: any): Observable<Tutorial> {
    return this.http.get(`${baseUrl}/${id}`);
  }

  create(data: any): Observable<any> {
    return this.http.post(baseUrl, data);
  }

  update(id: any, data: any): Observable<any> {
    return this.http.put(`${baseUrl}/${id}`, data);
  }

  delete(id: any): Observable<any> {
    return this.http.delete(`${baseUrl}/${id}`);
  }

  deleteAll(): Observable<any> {
    return this.http.delete(baseUrl);
  }

  findByTitle(title: any): Observable<Tutorial[]> {
    return this.http.get<Tutorial[]>(`${baseUrl}?title=${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 12 CRUD Application example with Web API

Other versions:
Angular 8 CRUD Application example with Web API
Angular 10 CRUD Application example with Web API
Angular 11 CRUD Application example with Web API

Run the Angular 12 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

Security: Angular 12 + Spring Boot: JWT Authentication & Authorization example

Upload: Angular 12 + Spring Boot: File upload example

If you want to implement Form Validation, please visit:
Angular 12 Form Validation example (Reactive Forms)

Or Pagination: Angular 12 + Spring Boot: Pagination example

Conclusion

Now we have an overview of Angular 12 + Spring Boot 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 12 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 (with Github source code):
– Back-end:

– Front-end:

Happy learning, see you again!

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