Spring Boot 3 + PostgreSQL + Angular 14 CRUD Application Example

 Hello everyone, today we will learn how to develop a Full-stack web application that is a basic User Management Application using Spring Boot 3, Spring Data JPA, PostgreSQL and Angular 14. The GitHub repository link is provided at the end of this tutorial. You can download the source code.

View All Users:


Add User:


Update User:



We divided this tutorial into two parts. 

PART 1 - Restful API Development with Spring Boot 3
PART 2 - UI development using Angular 14


PART 1 - Restful API Development with Spring Boot 3

These are APIs that Spring backend App will export:


Backend project structure:



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.
<?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 
   https://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>3.0.1</version>
      <relativePath/> <!-- lookup parent from repository -->
   </parent>
   <groupId>com.knf.dev.demo</groupId>
   <artifactId>crud-application</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <name>crud-application</name>
   <description>Demo project for Spring Boot</description>
   <properties>
      <java.version>17</java.version>
   </properties>
   <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>org.postgresql</groupId>
         <artifactId>postgresql</artifactId>
         <scope>runtime</scope>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-test</artifactId>
         <scope>test</scope>
      </dependency>
   </dependencies>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
         </plugin>
      </plugins>
   </build>

</project>


Configuring PostgreSQL Database

First, you need to create a database in the PostgreSQL server. You can use the following command to create a database in the PostgresSQL server:
CREATE DATABASE users;

Now, let’s configure the Spring Boot application to use PostgreSQL as our data source. You can do that simply by adding PostgreSQL database URL, username, and password in the src/main/resources/application.properties file.

Open src/main/resources/application.properties file and add the following content to it:

spring.datasource.url=jdbc:postgresql://localhost:5432/users
spring.datasource.username=postgres
spring.datasource.password=root
spring.jpa.show-sql=true

# Hibernate ddl auto (create, create-drop, validate, update)
spring.jpa.hibernate.ddl-auto = update


Create User Entity

package com.knf.dev.demo.crudapplication.entity;

import jakarta.persistence.*;

@Entity
@Table(name = "userTable")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
    @Column(name = "first_name")
    private String firstName;
    @Column(name = "last_name")
    private String lastName;
    @Column(name = "email_id")
    private String emailId;

    public User() {
    }

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

    public long getId() {
        return id;
    }

    public void setId(long 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;
    }
}
The @Entity annotation specifies that the class is an entity and is mapped to a database table. The @Id annotation specifies the primary key of an entity and the @GeneratedValue provides for the specification of generation strategies for the values of primary keys. The @Column annotation is used to specify the mapped column for a persistent property or field. If no Column annotation is specified, the default value will be applied.


Create UserRepository

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

import com.knf.dev.demo.crudapplication.entity.User;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface UserRepository extends JpaRepository<User, Long> {

}



Create CustomErrorResponse

package com.knf.dev.demo.crudapplication.exception;

import com.fasterxml.jackson.annotation.JsonFormat;
import java.time.LocalDateTime;

public class CustomErrorResponse {

    @JsonFormat(shape = JsonFormat.Shape.STRING,
            pattern = "yyyy-MM-dd hh:mm:ss")
    private LocalDateTime timestamp;
    private int status;
    private String error;
    public LocalDateTime getTimestamp() {
        return timestamp;
    }
    public void setTimestamp(LocalDateTime timestamp) {
        this.timestamp = timestamp;
    }
    public int getStatus() {
        return status;
    }
    public void setStatus(int status) {
        this.status = status;
    }
    public String getError() {
        return error;
    }
    public void setError(String error) {
        this.error = error;
    }
}



Create ResourceNotFoundException

package com.knf.dev.demo.crudapplication.exception;

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException{

   private static final long serialVersionUID = 1L;
   
   public ResourceNotFoundException(String message) {
      super(message);
   }
}



Create GlobalExceptionHandler

package com.knf.dev.demo.crudapplication.exception;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;

import java.time.LocalDateTime;

@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity<CustomErrorResponse> globalExceptionHandler
                   (Exception ex, WebRequest request) {
        CustomErrorResponse errors = new CustomErrorResponse();
        errors.setTimestamp(LocalDateTime.now());
        errors.setError(ex.getMessage());
        errors.setStatus(HttpStatus.NOT_FOUND.value());
        return new ResponseEntity<>(errors, HttpStatus.NOT_FOUND);
    }
}



Create UserController

package com.knf.dev.demo.crudapplication.controller;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.knf.dev.demo.crudapplication.entity.User;
import com.knf.dev.demo.crudapplication.exception.ResourceNotFoundException;
import com.knf.dev.demo.crudapplication.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;


@CrossOrigin(origins = "*")
@RestController
@RequestMapping("/api/v1")
public class UserController {
    @Autowired
    private UserRepository userRepository;

    // get all users
    @GetMapping("/users")
    public List<User> getAllUsers() {
        return userRepository.findAll();
    }

    // create user rest API
    @PostMapping("/users")
    public User createUser(@RequestBody User user) {
        return userRepository.save(user);
    }

    // get user by id rest api
    @GetMapping("/users/{id}")
    public ResponseEntity<User> getUserById(@PathVariable Long id) {
        User user = userRepository.findById(id)
                .orElseThrow(() -> new ResourceNotFoundException
                      ("User not exist with id :" + id));
        return ResponseEntity.ok(user);
    }

    // update user rest api
    @PutMapping("/users/{id}")
    public ResponseEntity<User> updateUser(@PathVariable Long id,
             @RequestBody User userDetails) {
        User user = userRepository.findById(id)
                .orElseThrow(() -> new ResourceNotFoundException
                      ("User not exist with id :" + id));
        user.setFirstName(userDetails.getFirstName());
        user.setLastName(userDetails.getLastName());
        user.setEmailId(userDetails.getEmailId());
        User updatedUser = userRepository.save(user);
        return ResponseEntity.ok(updatedUser);
    }

    // delete user rest api
    @DeleteMapping("/users/{id}")
    public ResponseEntity<Map<String, Boolean>> deleteUser
               (@PathVariable Long id) {
        User user = userRepository.findById(id)
                .orElseThrow(() -> new ResourceNotFoundException
            ("User not exist with id :" + id));
        userRepository.delete(user);
        Map<String, Boolean> response = new HashMap<>();
        response.put("deleted", Boolean.TRUE);
        return ResponseEntity.ok(response);
    }
}



Main Driver

package com.knf.dev.demo.crudapplication;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class CrudApplication {

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

}



Run the application and verify REST APIs


Step 1: mvn clean install


Step 2: Run the Spring Boot application - mvn spring-boot:run

Add User:


Update User by ID:


Fetch all Users:


Get User by ID:


Delete User by ID:




PART 2 - UI development using Angular 14

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": "crud-application",
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "watch": "ng build --watch --configuration development",
    "test": "ng test"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^14.1.0",
    "@angular/common": "^14.1.0",
    "@angular/compiler": "^14.1.0",
    "@angular/core": "^14.1.0",
    "@angular/forms": "^14.1.0",
    "@angular/platform-browser": "^14.1.0",
    "@angular/platform-browser-dynamic": "^14.1.0",
    "@angular/router": "^14.1.0",
    "bootstrap": "^5.2.0",
    "rxjs": "~7.5.0",
    "tslib": "^2.3.0",
    "zone.js": "~0.11.4"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "^14.1.1",
    "@angular/cli": "~14.1.1",
    "@angular/compiler-cli": "^14.1.0",
    "@types/jasmine": "~4.0.0",
    "jasmine-core": "~4.2.0",
    "karma": "~6.4.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage": "~2.2.0",
    "karma-jasmine": "~5.1.0",
    "karma-jasmine-html-reporter": "~2.0.0",
    "typescript": "~4.7.2"
  }
}


The User.ts file(User Model)

Path - src/app/service/user.ts

export class User {
  id!: number;
  firstName!: String;
  lastName!: String;
  emailId!: String;
}


CRUD Service

Path - src/app/service/crud.service.ts 

The CrudService will be used to get the data from the backend by calling  APIs. Update the crud.service.ts file inside src/app/service directory with the following code to it -
import { Injectable } from '@angular/core';
import { User } from './User';
import { catchError, map } from 'rxjs/operators';
import { Observable, throwError } from 'rxjs';
import {
  HttpClient,
  HttpHeaders,
  HttpErrorResponse,
} from '@angular/common/http';

@Injectable({
  providedIn: 'root',
})
export class CrudService {
  
  REST_API: string = 'http://localhost:8080/api/v1';

  // Http Header
  httpHeaders = new HttpHeaders().set('Content-Type', 'application/json');

  constructor(private httpClient: HttpClient) {}

  // Add
  AddUser(data: User): Observable<any> {
    let API_URL = `${this.REST_API}/users`;
    return this.httpClient
      .post(API_URL, data)
      .pipe(catchError(this.handleError));
  }

  // Get all objects
  GetUsers() {
    return this.httpClient.get(`${this.REST_API}/users`);
  }

  // Get single object
  GetUser(id: any): Observable<any> {
    let API_URL = `${this.REST_API}/users/${id}`;
    return this.httpClient.get(API_URL, { headers: this.httpHeaders }).pipe(
      map((res: any) => {
        return res || {};
      }),
      catchError(this.handleError)
    );
  }

  // Update
  updateUser(id: any, data: any): Observable<any> {
    let API_URL = `${this.REST_API}/users/${id}`;
    return this.httpClient
      .put(API_URL, data, { headers: this.httpHeaders })
      .pipe(catchError(this.handleError));
  }

  // Delete
  deleteUser(id: any): Observable<any> {
    let API_URL = `${this.REST_API}/users/${id}`;
    return this.httpClient
      .delete(API_URL, { headers: this.httpHeaders })
      .pipe(catchError(this.handleError));
  }

  // Error
  handleError(error: HttpErrorResponse) {
    let errorMessage = '';
    if (error.error instanceof ErrorEvent) {
      // Handle client error
      errorMessage = error.error.message;
    } else {
      // Handle server error
      errorMessage = `Error Code: ${error.status}\nMessage: ${error.message}`;
    }
    console.log(errorMessage);
    return throwError(() => {
      errorMessage;
    });
  }
}


User List Component

Let's create the UserListComponent component which will be used to display a list of users, create a new user, and delete a user.

Path - src/app/user-list/user-list.component.ts
import { Component, OnInit } from '@angular/core';
import { CrudService } from '../../service/crud.service';

@Component({
  selector: 'app-users-list',
  templateUrl: './users-list.component.html',
  styleUrls: ['./users-list.component.scss'],
})
export class UsersListComponent implements OnInit {
  Users: any = [];

  constructor(private crudService: CrudService) {}

  ngOnInit(): void {
    this.crudService.GetUsers().subscribe((res: any) => {
      console.log(res);
      this.Users = res;
    });
  }

  delete(id: any, i: any) {
    console.log(id);
    if (window.confirm('Do you want to go ahead?')) {
      this.crudService.deleteUser(id).subscribe(() => {
        this.Users.splice(i, 1);
      });
    }
  }
}


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="container">
  <div
    class="d-flex justify-content-between 
              flex-wrap flex-md-nowrap  
         align-items-center pt-3 pb-2 mb-3 border-bottom">
    <h2 class="h2">Users Collection</h2>
  </div>

  <div class="table-responsive">
    <table class="table table-bordered">
      <thead>
        <tr>
          <th scope="col">ID</th>
          <th scope="col">First Name</th>
          <th scope="col">Last Name</th>
          <th scope="col">Email</th>
          <th class="text-center" scope="col">Action</th>
        </tr>
      </thead>
      <tbody>
        <tr *ngFor="let user of Users; let i = index">
          <th scope="row">{{ user.id }}</th>
          <td>{{ user.firstName }}</td>
          <td>{{ user.lastName }}</td>
          <td>{{ user.emailId }}</td>
          <td class="text-center">
            <button
              class="btn btn-sm btn-primary"
              routerLink="/edit-user/{{ user.id }}"
            >
              Edit
            </button>
            <button class="btn btn-sm btn-danger" 
                (click)="delete(user.id, i)">
              Delete
            </button>
          </td>
        </tr>
      </tbody>
    </table>
  </div>
</div>


Add User Component

Path - src/app/add-user/add-user.component.ts

AddUserComponent is used to create and handle new user form data. Add the following code to it -
import { Component, OnInit, NgZone } from '@angular/core';
import { Router } from '@angular/router';
import { CrudService } from '../../service/crud.service';
import { FormGroup, FormBuilder } from '@angular/forms';

@Component({
  selector: 'app-add-user',
  templateUrl: './add-user.component.html',
  styleUrls: ['./add-user.component.scss'],
})
export class AddUserComponent implements OnInit {
  userForm: FormGroup;

  constructor(
    public formBuilder: FormBuilder,
    private router: Router,
    private ngZone: NgZone,
    private crudService: CrudService
  ) {
    this.userForm = this.formBuilder.group({
      firstName: [''],
      lastName: [''],
      emailId: [''],
    });
  }

  ngOnInit() {}

  onSubmit(): any {
    this.crudService.AddUser(this.userForm.value).subscribe(
      () => {
        console.log('Data added successfully!');
        this.ngZone.run(() => this.router.navigateByUrl('/users-list'));
      },
      (err) => {
        console.log(err);
      }
    );
  }
}


Add User Template

The add-user.component.html shows the add using HTML form. Add the following code to it -

Path - src/app/add-user/add-user.component.html 
<div class="row justify-content-center mt-5">
  <div class="col-md-4">
    <form [formGroup]="userForm" (ngSubmit)="onSubmit()">
      <div class="form-group">
        <label>First Name</label>
        <input
          class="form-control"
          type="text"
          formControlName="firstName"
          required
        />
      </div>

      <div class="form-group">
        <label>Last Name</label>
        <input
          class="form-control"
          type="text"
          formControlName="lastName"
          required
        />
      </div>

      <div class="form-group">
        <label>Email</label>
        <input
          class="form-control"
          type="text"
          formControlName="emailId"
          required
        />
      </div>
      <br>
      <div class="form-group">
        <button class="btn btn-primary btn-block" type="submit">
          Add User
        </button>
      </div>
    </form>
  </div>
</div>


User Detail Component

Path - src/app/user-detail/user-detail.component.ts 

The UserDetailComponent component is used to display a particular user detail. Add the following code to it -
import { Component, OnInit, NgZone } from '@angular/core';
import { Router, ActivatedRoute } from '@angular/router';
import { CrudService } from '../../service/crud.service';
import { FormGroup, FormBuilder } from '@angular/forms';

@Component({
  selector: 'app-user-detail',
  templateUrl: './user-detail.component.html',
  styleUrls: ['./user-detail.component.scss'],
})
export class UserDetailComponent implements OnInit {
  getId: any;
  updateForm: FormGroup;

  constructor(
    public formBuilder: FormBuilder,
    private router: Router,
    private ngZone: NgZone,
    private activatedRoute: ActivatedRoute,
    private crudService: CrudService
  ) {
    this.getId = this.activatedRoute.snapshot.paramMap.get('id');

    this.crudService.GetUser(this.getId).subscribe((res: { [x: string]: any; }) => {
      this.updateForm.setValue({
        firstName: res['firstName'],
        lastName: res['lastName'],
        emailId: res['emailId'],
      });
    });

    this.updateForm = this.formBuilder.group({
      firstName: [''],
      lastName: [''],
      emailId: [''],
    });
  }

  ngOnInit() {}

  onUpdate(): any {
    this.crudService.updateUser(this.getId, this.updateForm.value).subscribe(
      () => {
        console.log('Data updated successfully!');
        this.ngZone.run(() => this.router.navigateByUrl('/users-list'));
      },
      (err) => {
        console.log(err);
      }
    );
  }
}


User Details  Template

Path - src/app/user-detail/user-detail.component.html 

The user-detail.component.html displays a particular user detail. Add the following code to it -
<div class="row justify-content-center mt-5">
  <div class="col-md-4">
    <form [formGroup]="updateForm" (ngSubmit)="onUpdate()">
      <div class="form-group">
        <label>First Name</label>
        <input
          class="form-control"
          type="text"
          formControlName="firstName"
          required
        />
      </div>

      <div class="form-group">
        <label>Last Name</label>
        <input
          class="form-control"
          type="text"
          formControlName="lastName"
          required
        />
      </div>

      <div class="form-group">
        <label>Email</label>
        <input
          class="form-control"
          type="text"
          formControlName="emailId"
          required
        />
      </div>
      <br>
      <div class="form-group">
        <button class="btn btn-primary btn-block"
              type="submit">Update</button>
      </div>
    </form>
  </div>
</div>


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 { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';

import { UsersListComponent } from './components/users-list/users-list.component';
import { AddUserComponent } from './components/add-user/add-user.component';
import { UserDetailComponent } from './components/user-detail/user-detail.component';

const routes: Routes = [
  { path: '', pathMatch: 'full', redirectTo: 'add-user' },
  { path: 'users-list', component: UsersListComponent },
  { path: 'add-user', component: AddUserComponent },
  { path: 'edit-user/:id', component: UserDetailComponent },
];

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


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 { AppComponent } from './app.component';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';
import { AppRoutingModule } from './app-routing.module';
import { AddUserComponent } from './components/add-user/add-user.component';
import { UserDetailComponent } from './components/user-detail/user-detail.component';
import { UsersListComponent } from './components/users-list/users-list.component';

@NgModule({
  declarations: [
    AppComponent,
    AddUserComponent,
    UserDetailComponent,
    UsersListComponent,
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
    FormsModule,
    ReactiveFormsModule,
    AppRoutingModule,
  ],
  providers: [],
  bootstrap: [AppComponent],
})
export class AppModule {}


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.scss']
})
export class AppComponent {
  title = 'Spring Boot 3 + PostgreSQL + Angular 14 CRUD Application';
}


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 class="nav-link" routerLinkActive="active" routerLink="/users-list"
      >Show Users</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" routerLinkActive="active" routerLink="/add-user"
      >Add Users</a
    >
    </li>
  </ul>
</nav>
<div class="container">
  <br>
  <h2 style="text-align: center;">{{title}}</h2>
  <hr>  
  <router-outlet></router-outlet>
</div>

<router-outlet></router-outlet>


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>AngularSpringPostgreSQLCrud</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/Bootstrap 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: any) => console.error(err));



Local Setup and Run the application

Step 1: Download or clone the source code from GitHub to a local machine - Click here



Backend


Step 2: mvn clean install


Step 3: Run the Spring Boot application - mvn spring-boot:run



Frontend


Step 4: npm install 


Step 5: ng serve

From the browser call the endpoint http://localhost:4200/



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