Angular 12 + Spring Boot + MongoDB example: CRUD Application

In this tutorial, we will learn how to build a full stack Angular 12 + Spring Boot + MongoDB example with a CRUD App. The back-end server uses Spring Boot with Spring Web MVC for REST Controller and Spring Data MongoDB for interacting with MongoDB database. Front-end side is made with Angular 12, HTTPClient & Router.

More Practice:
– Angular + Spring Boot: Pagination example
– Angular 12 + Spring Boot: JWT Authentication & Authorization example
– Angular 12 + Spring Boot: File upload example

Serverless with Firebase:
– Angular 12 Firebase CRUD Realtime DB | AngularFireDatabase
– Angular 12 Firestore CRUD example | AngularFireStore

Newer versions:
– Angular 13 + Spring Boot + MongoDB example
– Angular 14 + Spring Boot + MongoDB example
– Angular 15 + Spring Boot + MongoDB example
– Angular 16 + Spring Boot + MongoDB example

Angular 12 + Spring Boot + MongoDB CRUD example

We will build a full-stack Tutorial 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 a Tutorial:

– Retrieve all Tutorials:

– Click on Edit button to update a Tutorial:

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

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

– Search Tutorials by title:

– This is tutorials collection on the MongoDB database:

Angular 12 & Spring Boot MongoDB Architecture

This is the application architecture we will build:

– Spring Boot exports REST Apis using Spring Web MVC & interacts with MongoDB Database using Spring Data MongoDB.
– 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.

Spring Boot Back-end

Overview

These are APIs that Spring Boot App will export:

We make CRUD operations & finder methods with Spring Data MongoDB’s MongoRepository.

Technology

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

Project Structure

• Tutorial data model class corresponds to entity and table tutorials.
• TutorialRepository is an interface that extends MongoRepository 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 Data MongoDB is in application.properties.
• pom.xml contains dependencies for Spring Boot Web MVC and Spring Data MongoDB.

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-web</artifactId>
</dependency>

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

Configure Spring Data MongoDB

Under src/main/resources folder, open application.properties and add following lines.

spring.data.mongodb.database=bezkoder_db
spring.data.mongodb.port=27017

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.data.mongodb.model;

import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;

@Document(collection = "tutorials")
public class Tutorial {
  @Id
  private String id;

  private String title;
  private String description;
  private boolean published;

  ...
}

@Document annotation helps us override the collection name by “tutorials”.

Create Repository Interface

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

repository/TutorialRepository.java

package com.bezkoder.spring.data.mongodb.repository;

import java.util.List;

import org.springframework.data.mongodb.repository.MongoRepository;

import com.bezkoder.spring.data.mongodb.model.Tutorial;

public interface TutorialRepository extends MongoRepository<Tutorial, String> {
  List<Tutorial> findByTitleContaining(String title);
  List<Tutorial> findByPublished(boolean published);
}

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

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

The implementation is plugged in by Spring Data MongoDB automatically.

You can modify this Repository to work with Pagination, the instruction can be found at:
Spring Boot MongoDB Pagination example with Spring Data

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.data.mongodb.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") String id) {
    
  }

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

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

  @DeleteMapping("/tutorials/{id}")
  public ResponseEntity<HttpStatus> deleteTutorial(@PathVariable("id") String 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 with MongoDB CRUD example using Spring Data

Or Reactive Rest API: Spring Boot, MongoDB, Reactive CRUD example

Run Spring Boot Server

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

Angular 12 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

– 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 example with Web API
– Angular 10 CRUD example with Web API
– Angular 11 CRUD example with Web API
– Angular 13 CRUD example with Web API
– Angular 14 CRUD example with Web API
– Angular 15 CRUD example with Web API
– Angular 16 CRUD 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.

• Spring Data MongoDB
• Spring Web MVC
• Angular HttpClient
• Angular Template Syntax

Source Code

You can find Github source code for this tutorial at: Spring Boot + Angular example Github

Conclusion

Now we have an overview of Angular 12 + Spring Boot + MongoDB CRUD example when building a CRUD App.

We also take a look at client-server architecture for REST API using Spring Web MVC & Spring Data MongoDB, 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:
– Back-end / Back-end with Reactive API

– Front-end:

• Using Angular 10
• Using Angular 11
• Using Angular 12
• Using Angular 13
• Using Angular 14
• Using Angular 15
• Using Angular 16

You will want to know how to run both projects in one place:
How to Integrate Angular 12 with Spring Boot Rest API

Server side Pagination:
– Front-end: Angular 12 Pagination example
– Back-end: Spring Boot MongoDB Pagination example with Spring Data

Or Angular uploading File to Spring Boot Server:
Angular 12 + Spring Boot: File upload example

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

Serverless with Firebase:
– Angular Firebase CRUD Realtime DB | AngularFireDatabase
– Angular Firestore CRUD example | AngularFireStore

Happy learning, see you again!