Micronaut + Angular + MongoDB CRUD Example

Hello everyone, today we will learn how to develop a full-stack web application that is a basic User Management Application using Micronaut, Angular, and MongoDB.
GitHub repository link is provided at the end of this tutorial. You can download the source code.

After completing this tutorial what we will build? 

We will build a full-stack web application that is a basic User Management Application with CRUD features:

• Create User
• List User
• Update User 
• Delete User 

Add User:


Retrieve All Users:


Update User:


View User:


We divided this tutorial into two parts. 

PART 1 - Rest APIs Development using Micronaut
PART 2 - UI development using Angular 10

 PART 1 - Rest APIs Development using Micronaut 

Project Directory:



Maven[pom.xml]

A Project Object Model or POM is the fundamental unit of work in Maven. It is an XML file that contains information about the project and configuration details utilized by Maven to build the project. It contains default values for most projects. Some of the configurations that can be designated in the POM is the project dependencies, the plugins or goals that can be executed, the build profiles, and so on. Other information such as the project version, description, developers, mailing lists and such can withal be designated.
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.knf.dev.demo</groupId>
<artifactId>micronaut-mongodb-crud</artifactId>
<version>0.1</version>
<packaging>${packaging}</packaging>

<parent>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-parent</artifactId>
<version>3.1.1</version>
</parent>

<properties>
<packaging>jar</packaging>
<jdk.version>11</jdk.version>
<release.version>11</release.version>
<micronaut.version>3.1.1</micronaut.version>
<exec.mainClass>com.knf.dev.demo.Application</exec.mainClass>
<micronaut.runtime>netty</micronaut.runtime>
</properties>

<repositories>
<repository>
<id>central</id>
<url>https://repo.maven.apache.org/maven2</url>
</repository>
</repositories>

<dependencies>
<dependency>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-inject</artifactId>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-validation</artifactId>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-http-server-netty</artifactId>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-http-client</artifactId>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-runtime</artifactId>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>javax.annotation</groupId>
<artifactId>javax.annotation-api</artifactId>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>io.micronaut.mongodb</groupId>
<artifactId>micronaut-mongo-sync</artifactId>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-api</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>io.micronaut.test</groupId>
<artifactId>micronaut-test-junit5</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

<build>
<plugins>
<plugin>
<groupId>io.micronaut.build</groupId>
<artifactId>micronaut-maven-plugin</artifactId>
</plugin>

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<annotationProcessorPaths>
<path>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-inject-java</artifactId>
<version>${micronaut.version}</version>
</path>
<path>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-validation</artifactId>
<version>${micronaut.version}</version>
</path>
</annotationProcessorPaths>
<compilerArgs>
<arg>-Amicronaut.processing.group=com.knf.dev.demo</arg>
<arg>-Amicronaut.processing.module=micronaut-mongodb-crud</arg>
</compilerArgs>
</configuration>
</plugin>
</plugins>
</build>
</project>



application.yaml

micronaut:
application:
name: micronautMongodbCrud
mongodb.uri: mongodb://localhost:27017

micronaut:
server:
cors:
enabled: true
configurations:
web:
allowedOrigins:
- http://localhost:4200


Create Document - User.java

package com.knf.dev.demo.entity;

import io.micronaut.core.annotation.Introspected;

@Introspected
public class User {
private String id;
private String firstName;
private String lastName;
private String emailId;

public String getId() {
return id;
}

public void setId(String id) {
this.id = id;
}

public String getFirstName() {
return firstName;
}

public void setFirstName(String firstName) {
this.firstName = firstName;
}

public String getLastName() {
return lastName;
}

public void setLastName(String lastName) {
this.lastName = lastName;
}

public String getEmailId() {
return emailId;
}

public void setEmailId(String emailId) {
this.emailId = emailId;
}

public User(String id, String firstName,
String lastName, String emailId) {
super();
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.emailId = emailId;
}

public User() {
super();
}

}


Create UserRepository.java

package com.knf.dev.demo.repository.impl;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import org.bson.Document;
import org.bson.conversions.Bson;
import org.bson.types.ObjectId;
import com.knf.dev.demo.entity.User;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.model.Filters;
import jakarta.inject.Singleton;

@Singleton
public class UserRepository {
private final MongoClient mongoClient;

public UserRepository(MongoClient mongoClient) {

this.mongoClient = mongoClient;
}

private MongoCollection<Document> getCollection() {

return mongoClient.getDatabase("user-test").
getCollection("user-test");
}

public User saveUser(User user) {
Document document = new Document().
append("firstName", user.getFirstName())
.append("lastName", user.getLastName()).
append("emailId", user.getEmailId());
getCollection().insertOne(document);
user.setId(document.getObjectId("_id").toString());
return user;
}

public User updateUser(String id, User user) {
Optional<Document> optionalDocument =
findDocumentById(id);
if (optionalDocument.isPresent()) {
Document document = optionalDocument.get();
document.put("firstName", user.getFirstName());
document.put("lastName", user.getLastName());
document.put("emailId", user.getEmailId());
Bson bsonFilter = Filters.
eq("_id", new ObjectId(id));
getCollection().replaceOne(bsonFilter, document);
}
return user;
}

public List<User> findAll() {

List<User> users = new ArrayList<>();
MongoCursor<Document> cursor =
getCollection().find().iterator();

try {
while (cursor.hasNext()) {
Document document = cursor.next();
User user = new User();
user.setLastName(document.
getString("lastName"));
user.setFirstName(document.
getString("firstName"));
user.setEmailId(document.
getString("emailId"));
user.setId(String.valueOf(document.
getObjectId("_id")));
users.add(user);
}
} finally {
cursor.close();
}
return users;
}

public Optional<User> findUserById(String id) {

return findDocumentById(id).map(this::mapUser);
}

public void deleteUserById(String id) {
Bson bsonFilter = Filters.
eq("_id", new ObjectId(id));
getCollection().deleteOne(bsonFilter);
}

private Optional<Document> findDocumentById(String id) {
Bson bsonFilter = Filters.
eq("_id", new ObjectId(id));
try (MongoCursor<Document> iterator =
getCollection().
find(bsonFilter).iterator()) {
return iterator.hasNext() ? Optional.
of(iterator.next()) : Optional.empty();
}
}

private User mapUser(Document document) {
User user = new User();
user.setId(document.getObjectId("_id").toString());
user.setEmailId(document.getString("emailId"));
user.setLastName(document.getString("lastName"));
user.setFirstName(document.getString("firstName"));
return user;
}
}


Create UserController.java

package com.knf.dev.demo.contoller;

import java.util.List;
import java.util.Optional;
import com.knf.dev.demo.entity.User;
import com.knf.dev.demo.repository.impl.UserRepository;
import io.micronaut.http.HttpResponse;
import io.micronaut.http.annotation.Body;
import io.micronaut.http.annotation.Controller;
import io.micronaut.http.annotation.Delete;
import io.micronaut.http.annotation.Get;
import io.micronaut.http.annotation.Post;
import io.micronaut.http.annotation.Put;
import jakarta.inject.Inject;

@Controller("/api/v1/users")
public class UserController {

@Inject
UserRepository userRepository;

@Get
public List<User> getUsers() {
return userRepository.findAll();
}

@Get("/{id}")
public Optional<User> getUser(String id) {
return userRepository.findUserById(id);
}

@Post
public HttpResponse<User> addUser(@Body User user) {
userRepository.saveUser(user);
return HttpResponse.created(user);
}

@Put("/{id}")
public HttpResponse<User>
updateUser(String id, @Body User user) {
userRepository.updateUser(id, user);
return HttpResponse.created(user);
}

@Delete("/{id}")
public HttpResponse<Void> delete(String id) {
userRepository.deleteUserById(id);
return HttpResponse.noContent();
}
}


Create Main Class

package com.knf.dev.demo;

import io.micronaut.runtime.Micronaut;

public class Application {

public static void main(String[] args) {
Micronaut.run(Application.class, args);
}
}


Run the backend application

mvn mn:run or run as java application



PART 2 - UI development using Angular 10

Project Structure



The package.json

A package.json is a JSON file that subsists at the root of a Javascript/Node project. It holds metadata pertinent to the project and is utilized for managing the project's dependencies, scripts, version, and a whole lot more.
{
"name": "front-end-simple-crud",
"version": "0.0.0",
"scripts": {
"ng": "ng",
"start": "ng serve",
"build": "ng build",
"test": "ng test",
"lint": "ng lint",
"e2e": "ng e2e"
},
"private": true,
"dependencies": {
"@angular/animations": "~10.1.2",
"@angular/common": "~10.1.2",
"@angular/compiler": "~10.1.2",
"@angular/core": "~10.1.2",
"@angular/forms": "~10.1.2",
"@angular/platform-browser": "~10.1.2",
"@angular/platform-browser-dynamic": "~10.1.2",
"@angular/router": "~10.1.2",
"bootstrap": "^4.5.3",
"jquery": "^3.5.1",
"rxjs": "~6.6.0",
"tslib": "^2.0.0",
"zone.js": "~0.10.2"
},
"devDependencies": {
"@angular-devkit/build-angular": "^0.1100.3",
"@angular/cli": "~10.1.2",
"@angular/compiler-cli": "~10.1.2",
"@types/jasmine": "~3.5.0",
"@types/jasminewd2": "~2.0.3",
"@types/node": "^12.11.1",
"codelyzer": "^6.0.0",
"jasmine-core": "~3.6.0",
"jasmine-spec-reporter": "~5.0.0",
"karma": "~5.0.0",
"karma-chrome-launcher": "~3.1.0",
"karma-coverage-istanbul-reporter": "~3.0.2",
"karma-jasmine": "~4.0.0",
"karma-jasmine-html-reporter": "^1.5.0",
"protractor": "~7.0.0",
"ts-node": "~8.3.0",
"tslint": "~6.1.0",
"typescript": "~4.0.2"
}
}



The User.ts file(User Model)

Path - src/app/user.ts 
Before defining the UserListComponent, let’s define a User class for working with users. create a new file user.ts inside src/app folder and add the following code to it -
export class User {
_id: string;
firstName: string;
lastName: string;
emailId: string;
active: boolean;

}



Create User List Template and Component

User List Component

Path - src/app/user-list/user-list.component.ts
Let's create the UserListComponent component which will be used to display a list of users, create a new user, and delete a user.
import { UserDetailsComponent } from '../user-details/user-details.component';
import { Observable } from "rxjs";
import { UserService } from "../user.service";
import { User } from "../user";
import { Component, OnInit } from "@angular/core";
import { Router } from '@angular/router';

@Component({
selector: "app-user-list",
templateUrl: "./user-list.component.html",
styleUrls: ["./user-list.component.css"]
})
export class UserListComponent implements OnInit {
users: Observable<User[]>;

constructor(private userService: UserService,
private router: Router) { }

ngOnInit() {
this.reloadData();
}

reloadData() {
this.users = this.userService.getUsersList();
}

deleteUser(_id: string) {
this.userService.deleteUser(_id)
.subscribe(
data => {
console.log(data);
this.reloadData();
},
error => console.log(error));
}
updateUser(id: string) {
this.router.navigate(['update', id]);
}
userDetails(_id: string) {
this.router.navigate(['details', _id]);
}
}



User List Template

Path - src/app/user-list/user-list.component.html
Add user-list.component.html file with the following code to it -
<div class="panel panel-primary">
<div class="panel-heading">
<h2>User List</h2>
</div>
<div class="panel-body">
<table class="table table-striped">
<thead>
<tr>
<th>Firstname</th>
<th>Lastname</th>
<th>Email</th>
<th>Actions</th>
</tr>
</thead>
<tbody>
<tr *ngFor="let user of users | async">
<td>{{user.firstName}}</td>
<td>{{user.lastName}}</td>
<td>{{user.emailId}}</td>
<td>
<button (click)="updateUser(user.id)"
class="btn btn-warning"
style="margin-left: 10px">Update</button>
<button (click)="deleteUser(user.id)"
class="btn btn-danger"
style="margin-left: 10px">Delete</button>
<button (click)="userDetails(user.id)"
class="btn btn-info"
style="margin-left: 10px">Details</button>
</td>
</tr>
</tbody>
</table>
</div>
</div>



Create Add User Template and Component

Add User Component

Path - src/app/create-user/create-user.component.ts
CreateUserComponent is used to create and handle new user form data. Add the following code to it -
import { UserService } from '../user.service';
import { User } from '../user';
import { Component, OnInit } from '@angular/core';
import { Router } from '@angular/router';

@Component({
selector: 'app-create-user',
templateUrl: './create-user.component.html',
styleUrls: ['./create-user.component.css']
})
export class CreateUserComponent implements OnInit {

user: User = new User();
submitted = false;

constructor(private userService: UserService,
private router: Router) { }

ngOnInit() {
}

newUser(): void {
this.submitted = false;
this.user = new User();
}

save() {
this.userService
.createUser(this.user).subscribe(data => {
console.log(data)
this.user = new User();
this.gotoList();
},
error => console.log(error));
}

onSubmit() {
this.submitted = true;
this.save();
}

gotoList() {
this.router.navigate(['/users']);
}
}



Create a User Template

Path - src/app/create-user/create-user.component.html 
The create-user.component.html shows the add using HTML form. Add the following code to it -
<h3>Create User</h3>
<div [hidden]="submitted" style="width: 400px;">
<form (ngSubmit)="onSubmit()">
<div class="form-group">
<label for="name">First Name</label>
<input type="text" class="form-control" id="firstName"
required [(ngModel)]="user.firstName" name="firstName">
</div>

<div class="form-group">
<label for="name">Last Name</label>
<input type="text" class="form-control" id="lastName"
required [(ngModel)]="user.lastName" name="lastName">
</div>

<div class="form-group">
<label for="name">Email Id</label>
<input type="text" class="form-control" id="emailId"
required [(ngModel)]="user.emailId" name="emailId">
</div>

<button type="submit" class="btn btn-danger">Submit</button>
</form>
</div>

<div [hidden]="!submitted">
<h4>Successfully submitted!</h4>
</div>


Update User Template and Component

Update User Component

Path - src/app/update-user/update-user.component.ts 
UpdateUserComponent is used to update an existing user.
import { Component, OnInit } from '@angular/core';
import { User } from '../user';
import { ActivatedRoute, Router } from '@angular/router';
import { UserService } from '../user.service';

@Component({
selector: 'app-update-user',
templateUrl: './update-user.component.html',
styleUrls: ['./update-user.component.css']
})
export class UpdateUserComponent implements OnInit {

_id: string;
user: User;

constructor(private route: ActivatedRoute, private router: Router,
private userService: UserService) { }

ngOnInit() {
this.user = new User();

this._id = this.route.snapshot.params['_id'];

this.userService.getUser(this._id)
.subscribe(data => {
this.user = data;
}, error => console.log(error));
}

updateUser() {
this.userService.updateUser(this._id, this.user)
.subscribe(data => {
console.log(data);
this.user = new User();
this.gotoList();
}, error => console.log(error));
}

onSubmit() {
this.updateUser();
}

gotoList() {
this.router.navigate(['/users']);
}
}



Update User Template

Path - src/app/update-user/update-user.component.html 
The update-user.component.html shows the updated user HTML form. Add the following code to this file -
<h3>Update User</h3>
<div style="width: 500px;">
<form (ngSubmit)="onSubmit()">
<div class="form-group">
<label for="name">First Name</label>
<input type="text" class="form-control" id="firstName"
required [(ngModel)]="user.firstName" name="firstName">
</div>

<div class="form-group">
<label for="name">Last Name</label>
<input type="text" class="form-control" id="lastName"
required [(ngModel)]="user.lastName" name="lastName">
</div>

<div class="form-group">
<label for="name">Email Id</label>
<input type="text" class="form-control" id="emailId"
required [(ngModel)]="user.emailId" name="emailId">
</div>

<button type="submit" class="btn btn-success">Submit</button>
</form>
</div>



Create a View User Details Template and Component

User Details Component

Path - src/app/user-details/user-details.component.ts 
The UserDetailsComponent component is used to display a particular user detail. Add the following code to it -
import { User } from '../user';
import { Component, OnInit, Input } from '@angular/core';
import { UserService } from '../user.service';
import { Router, ActivatedRoute } from '@angular/router';

@Component({
selector: 'app-user-details',
templateUrl: './user-details.component.html',
styleUrls: ['./user-details.component.css']
})
export class UserDetailsComponent implements OnInit {

_id: string;
user: User;

constructor(private route: ActivatedRoute,private router: Router,
private userService: UserService) { }

ngOnInit() {
this.user = new User();

this._id = this.route.snapshot.params['_id'];
console.log("gh"+this._id);
this.userService.getUser(this._id)
.subscribe(data => {
console.log(data)
this.user = data;
}, error => console.log(error));
}

list(){
this.router.navigate(['users']);
}
}



User Details  Template

Path - src/app/user-details/user-details.component.html 
The user-details.component.html displays a particular user detail. Add the following code to it -
<h2>User Details</h2>
<hr />
<div *ngIf="user">
<div>
<label><b>First Name: </b></label> {{user.firstName}}
</div>
<div>
<label><b>Last Name: </b></label> {{user.lastName}}
</div>
<div>
<label><b>Email Id: </b></label> {{user.emailId}}
</div>
</div>

<br>
<br>
<button (click)="list()"
class="btn btn-primary">User List</button><br>



User Service

Path - src/app/user.service.ts 
The UserService will be used to get the data from the backend by calling  APIs. Update the user.service.ts file inside src/app directory with the following code to it -
import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';

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

private baseUrl = 'http://localhost:8000/api/v1/users';

constructor(private http: HttpClient) { }

getUser(_id: string): Observable<any> {
return this.http.get(`${this.baseUrl}/${_id}`);
}

createUser(user: Object): Observable<Object> {
return this.http.post(`${this.baseUrl}`, user);
}

updateUser(_id: string, value: any): Observable<Object> {
return this.http.put(`${this.baseUrl}/${_id}`, value);
}

deleteUser(_id: string): Observable<any> {
return this.http.delete(`${this.baseUrl}/${_id}`,
{ responseType: 'text' });
}

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



App Routing Module

Path: /src/app/app.routing.module.ts 
Routing for the Angular app is configured as an array of Routes, each component is mapped to a path so the Angular Router knows which component to display based on the URL in the browser address bar.
import { UserDetailsComponent } from './user-details/user-details.component';
import { CreateUserComponent } from './create-user/create-user.component';
import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import {UserListComponent } from './user-list/user-list.component';
import { UpdateUserComponent } from './update-user/update-user.component';

const routes: Routes = [
{ path: '', redirectTo: 'user', pathMatch: 'full' },
{ path: 'users', component: UserListComponent },
{ path: 'add', component: CreateUserComponent },
{ path: 'update/:_id', component: UpdateUserComponent },
{ path: 'details/:_id', component: UserDetailsComponent },
];

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



App Component

Path: /src/app/app.component.ts 
The app component is the root component of the application, it defines the root tag of the app as with the selector property of the @Component decorator.
import { Component } from '@angular/core';

@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'Micronaut + Angular 10 + Mongo DB CRUD ';
}



App Component Template

Path: /src/app/app.component.html 
Defines the HTML template associated with the root AppComponent.
<nav class="navbar navbar-expand-sm bg-success navbar-dark">
<!-- Links -->
<ul class="navbar-nav">
<li class="nav-item">
<a routerLink="users" class="nav-link"
routerLinkActive="active">
User List</a>
</li>
<li class="nav-item">
<a routerLink="add" class="nav-link"
routerLinkActive="active">
Add User</a>
</li>
</ul>
</nav>
<div class="container">
<br>
<h2 style="text-align: center;">{{title}}</h2>
<hr>
<div class="card">
<div class="card-body">
<router-outlet></router-outlet>
</div>
</div>
</div>
<footer class="footer">
<div class="container">
<span>All Rights Reserved 2020 @Knowledge Factory</span>
</div>
</footer>



App Module

Path: /src/app/app.module.ts 
Defines the root module, named AppModule, that tells Angular how to assemble the application. Initially declares only the AppComponent. 
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { CreateUserComponent } from './create-user/create-user.component';
import { UserDetailsComponent } from './user-details/user-details.component';
import { UserListComponent } from './user-list/user-list.component';
import { UpdateUserComponent } from './update-user/update-user.component';
import { HttpClientModule } from '@angular/common/http';
@NgModule({
declarations: [
AppComponent,
CreateUserComponent,
UserDetailsComponent,
UserListComponent,
UpdateUserComponent
],
imports: [
BrowserModule,
AppRoutingModule,
FormsModule,
HttpClientModule
],
providers: [],
bootstrap: [AppComponent]
})
export class AppModule { }



index.html

Path: /src/index.html 
The main index.html file is the initial page loaded by the browser that kicks everything off.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Angular10CRUD</title>
<base href="/">
<meta name="viewport" content="width=device-width,
initial-scale=1">
<link rel="icon" type="image/x-icon" href="favicon.ico">
</head>
<body>
<app-root></app-root>
</body>
</html>



Main File

Path: /src/main.ts
The main file is the entry point used by angular to launch and bootstrap the application.
import { enableProdMode } from '@angular/core';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';

import { AppModule } from './app/app.module';
import { environment } from './environments/environment';

if (environment.production) {
enableProdMode();
}

platformBrowserDynamic().bootstrapModule(AppModule)
.catch(err => console.error(err));



Download the dependencies using the following command

npm install

Run the frontend application using the following command

ng serve

Hit http://localhost:4200 link in a browser that will host this Angular 10 CRUD app.

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