Spring Boot + Angular 6 CRUD Example


In this tutorial, we will learn how to develop a single page application(SPA) using Angular 6 as a front-end and Spring boot restful API as a backend.

What we will build?

Basically, we will create two projects:
  1. springboot2-jpa-crud-example: This project is used to develop CRUD RESTFul APIs for a simple Employee Management System using Spring Boot 2, JPA and MySQL as a database.
  2. angular6-springboot-client: This project is used to develop single page application using Angular 6 as front-end technology. This angular 6 application consumes CRUD Restful APIs developed and exposed by a springboot2-jpa-crud-example project.
Let me list out tools and technologies used to develop these two applications.

Tools and technologies used

Server-side technologies

  • Spring Boot - 2.0.4.RELEASE
  • JDK - 1.8 or later
  • Spring Framework - 5.0.8 RELEASE
  • Hibernate - 5.2.17.Final
  • Spring Data JPA - 2+

Front end technologies

  • Angular 6
  • Bootstrap 4
  • npm- 6.4.1
  • JQuery

Tools

  • Maven - 3.2+
  • IDE - Eclipse or Spring Tool Suite (STS)
  • Visual Studio 2017
  • Angular CLI

Spring Boot CRUD Rest APIs

Let's first we will build a CRUD RESTFul APIs for a Simple Employee Management System using Spring Boot 2 JPA and MySQL. Later we will consume these Rest APIs using Angular 6 client application. Following are five REST APIs (Controller handler methods) are created for Employee resource.

1. Creating and Importing a Project

There are many ways to create a Spring Boot application. The simplest way is to use Spring Initializrat http://start.spring.io/, which is an online Spring Boot application generator.
Look at the above diagram, we have specified the following details:
  • Generate: Maven Project
  • Java Version: 1.8 (Default)
  • Spring Boot:2.0.4
  • Group: net.guides.springboot2
  • Artifact: springboot2-jpa-crud-example
  • Name: springboot2-jpa-crud-example
  • Description: Rest API for a Simple Employee Management Application
  • Package Name : net.guides.springboot2.springboot2jpacrudexample
  • Packaging: jar (This is the default value)
  • Dependencies: Web, JPA, MySQL, DevTools
Once, all the details are entered, click on Generate Project button will generate a spring boot project and downloads it. Next, Unzip the downloaded zip file and import it into your favorite IDE.

2. Packaging Structure

Following is the packing structure of our Employee Management System -

3. The pom.xml File

<?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>net.guides.springboot2</groupId>
    <artifactId>springboot2-jpa-crud-example</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springboot2-jpa-crud-example</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</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.springframework.boot</groupId>
           <artifactId>spring-boot-devtools</artifactId>
           <scope>runtime</scope>
       </dependency>
       <dependency>
           <groupId>mysql</groupId>
           <artifactId>mysql-connector-java</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>

4. Create JPA Entity - Employee.java

package net.guides.springboot2.springboot2jpacrudexample.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "employees")
public class Employee {

    private long id;
    private String firstName;
    private String lastName;
    private String emailId;
 
    public Employee() {
  
    }
 
    public Employee(String firstName, String lastName, String emailId) {
         this.firstName = firstName;
         this.lastName = lastName;
         this.emailId = emailId;
    }
 
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
        public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
 
    @Column(name = "first_name", nullable = false)
    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
 
    @Column(name = "last_name", nullable = false)
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
 
    @Column(name = "email_address", nullable = false)
    public String getEmailId() {
        return emailId;
    }
    public void setEmailId(String emailId) {
        this.emailId = emailId;
    }

    @Override
    public String toString() {
        return "Employee [id=" + id + ", firstName=" + firstName + ", lastName=" + lastName + ", emailId=" + emailId
       + "]";
    }
 
}

5. Create Spring Data Repository - EmployeeRepository.java

package net.guides.springboot2.springboot2jpacrudexample.repository;

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

import net.guides.springboot2.springboot2jpacrudexample.model.Employee;

@Repository
public interface EmployeeRepository extends JpaRepository<Employee, Long>{

}

6. Create Spring Rest Controller - EmployeeController.java

package net.guides.springboot2.springboot2jpacrudexample.controller;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.validation.Valid;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
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;

import net.guides.springboot2.springboot2jpacrudexample.exception.ResourceNotFoundException;
import net.guides.springboot2.springboot2jpacrudexample.model.Employee;
import net.guides.springboot2.springboot2jpacrudexample.repository.EmployeeRepository;

@RestController
@RequestMapping("/api/v1")
public class EmployeeController {
    @Autowired
    private EmployeeRepository employeeRepository;

    @GetMapping("/employees")
    public List<Employee> getAllEmployees() {
        return employeeRepository.findAll();
    }

    @GetMapping("/employees/{id}")
    public ResponseEntity<Employee> getEmployeeById(@PathVariable(value = "id") Long employeeId)
        throws ResourceNotFoundException {
        Employee employee = employeeRepository.findById(employeeId)
          .orElseThrow(() -> new ResourceNotFoundException("Employee not found for this id :: " + employeeId));
        return ResponseEntity.ok().body(employee);
    }
    
    @PostMapping("/employees")
    public Employee createEmployee(@Valid @RequestBody Employee employee) {
        return employeeRepository.save(employee);
    }

    @PutMapping("/employees/{id}")
    public ResponseEntity<Employee> updateEmployee(@PathVariable(value = "id") Long employeeId,
         @Valid @RequestBody Employee employeeDetails) throws ResourceNotFoundException {
        Employee employee = employeeRepository.findById(employeeId)
        .orElseThrow(() -> new ResourceNotFoundException("Employee not found for this id :: " + employeeId));

        employee.setEmailId(employeeDetails.getEmailId());
        employee.setLastName(employeeDetails.getLastName());
        employee.setFirstName(employeeDetails.getFirstName());
        final Employee updatedEmployee = employeeRepository.save(employee);
        return ResponseEntity.ok(updatedEmployee);
    }

    @DeleteMapping("/employees/{id}")
    public Map<String, Boolean> deleteEmployee(@PathVariable(value = "id") Long employeeId)
         throws ResourceNotFoundException {
        Employee employee = employeeRepository.findById(employeeId)
       .orElseThrow(() -> new ResourceNotFoundException("Employee not found for this id :: " + employeeId));

        employeeRepository.delete(employee);
        Map<String, Boolean> response = new HashMap<>();
        response.put("deleted", Boolean.TRUE);
        return response;
    }
}

7. Running Application

This spring boot application has an entry point Java class called SpringBootCrudRestApplication.java with the public static void main(String[] args) method, which you can run to start the application.
import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}
The main() method uses Spring Boot’s SpringApplication.run() method to launch an application.
Or you can start spring boot application via command line using mvn spring-boot:run command.

This completes the development of Spring boot CRUD Rest APIs. Now we will develop client application using Angular 6.

Angular 6 Client Application

Let's develop a step by step Angular 6 SPA(single page application) to consume above CRUD rest APIs.
I am assuming that you have basic knowledge of using Angular 6 and Angular CLI.
The Angular CLI is a command-line interface tool that you use to initialize, develop, scaffold, and maintain Angular applications. 
If you are new to Angular CLI then check out official documentation at https://cli.angular.io.

Create Angular 6 client application using Angular CLI

You can install angular by typing the following command in your terminal -
$ npm install -g @angular/cli
Once installed, let's use below command to generate Angular 6 client application. We name this project as "angular6-springboot-client".
ng new angular6-springboot-client

Components, Services, and Modules

Let's list out what are components, service, and modules we are going to create in this application. We will use Angular CLI to generate components, services because Angular CLI follows best practices and saves much of time.
  1. Components
  • create-employee
  • employee-list
  • employee-details
  1. Services
  • employee.service.ts - Service for Http Client methods
  1. Modules
  • FormsModule
  • HttpClientModule
  • AppRoutingModule.
  1. Employee Class (Typescript class)
  • employee.ts: class Employee (id, firstName, lastName, emailId)
In this next step, we will generate these components, classes, and services using Angular CLI.

Create Service & Components

Let's auto-generate service and components using Angular CLI . Change your project directory to angular6-springboot-client\src\app and run following commands:
- ng g s employee
– ng g c create-employee
– ng g c employee-details
– ng g c employee-list
Here is complete command and output for your reference:
C:\angular6\angular6-springboot-client\src\app>ng g s employee
CREATE src/app/employee.service.spec.ts (343 bytes)
CREATE src/app/employee.service.ts (137 bytes)

C:\angular6\angular6-springboot-client\src\app>ng g c create-employee
CREATE src/app/create-employee/create-employee.component.html (34 bytes)
CREATE src/app/create-employee/create-employee.component.spec.ts (685 bytes)
CREATE src/app/create-employee/create-employee.component.ts (304 bytes)
CREATE src/app/create-employee/create-employee.component.css (0 bytes)
UPDATE src/app/app.module.ts (509 bytes)

C:\angular6\angular6-springboot-client\src\app>ng g c employee-details
CREATE src/app/employee-details/employee-details.component.html (35 bytes)
CREATE src/app/employee-details/employee-details.component.spec.ts (692 bytes)
CREATE src/app/employee-details/employee-details.component.ts (308 bytes)
CREATE src/app/employee-details/employee-details.component.css (0 bytes)
UPDATE src/app/app.module.ts (629 bytes)

C:\angular6\angular6-springboot-client\src\app>ng g c employee-list
CREATE src/app/employee-list/employee-list.component.html (32 bytes)
CREATE src/app/employee-list/employee-list.component.spec.ts (671 bytes)
CREATE src/app/employee-list/employee-list.component.ts (296 bytes)
CREATE src/app/employee-list/employee-list.component.css (0 bytes)
UPDATE src/app/app.module.ts (737 bytes)
We will using bootstrap 4 for styling our application so let's integrate bootstrap 4 with angular 6.

Integrate Bootstrap with Angular

Use NPM to download Bootstrap & JQuery. Bootstrap and jQuery will be installed into the node_modules folder.
npm install bootstrap jquery --save
Configure installed Bootstrap & JQuery in an angular.json file:
...
 
"styles": [
  "src/styles.css",
  "node_modules/bootstrap/dist/css/bootstrap.min.css"
],
"scripts": [
  "node_modules/jquery/dist/jquery.min.js",
  "node_modules/bootstrap/dist/js/bootstrap.min.js"
]
 
...
Let's discuss each of the above generate components and service files and we will customize it as per our requirement.

Create Employee class employee.ts

Before defining the EmployeeListComponent, let’s define an Employee class for working with employees. create a new file employee.ts inside src/app folder and add the following code to it -
export class Employee {
    id: number;
    firstName: string;
    lastName: string;
    emailId: string;
    active: boolean;
}

EmployeeService - employee-list.component.ts

The EmployeeService will be used to get the data from backend by calling spring boot APIs. Update the employee.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 EmployeeService {

  private baseUrl = '/api/v1/employees';

  constructor(private http: HttpClient) { }

  getEmployee(id: number): Observable<Object> {
    return this.http.get(`${this.baseUrl}/${id}`);
  }

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

  updateEmployee(id: number, value: any): Observable<Object> {
    return this.http.put(`${this.baseUrl}/${id}`, value);
  }

  deleteEmployee(id: number): Observable<any> {
    return this.http.delete(`${this.baseUrl}/${id}`, { responseType: 'text' });
  }

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

EmployeeListComponent - employee-list.component.ts

Let's update the EmployeeListComponent component which will be used to display a list of employee, create a new employee, and delete an employee.
Update/remove the content of todo-list.component.ts inside src/app directory and add the following code to it -
import { Observable } from "rxjs";
import { EmployeeService } from "./../employee.service";
import { Employee } from "./../employee";
import { Component, OnInit } from "@angular/core";

@Component({
  selector: "app-employee-list",
  templateUrl: "./employee-list.component.html",
  styleUrls: ["./employee-list.component.css"]
})
export class EmployeeListComponent implements OnInit {
  employees: Observable<Employee[]>;

  constructor(private employeeService: EmployeeService) {}

  ngOnInit() {
    this.reloadData();
  }

  reloadData() {
    this.employees = this.employeeService.getEmployeesList();
  }

  deleteEmployee(id: number) {
    this.employeeService.deleteEmployee(id)
      .subscribe(
        data => {
          console.log(data);
          this.reloadData();
        },
        error => console.log(error));
  }
}

Create a template for EmployeeListComponent employee-list.component.html

Update employee-list.component.html file with the following code to it -
<div class="panel panel-default">
    <div class="panel-heading">
        <h1>Employees</h1>
    </div>
    <div class="panel-body">
        <table class="table table-striped table-bordered">
            <thead>
                <tr>
                    <th>Firstname</th>
                    <th>Lastname</th>
                    <th>Email</th>
                    <th>Actions</th>
                </tr>
            </thead>
            <tbody>
                <tr *ngFor="let employee of employees | async">
                    <td>{{employee.firstName}}</td>
                    <td>{{employee.lastName}}</td>
                    <td>{{employee.emailId}}</td>
                    <td><button (click)="deleteEmployee(employee.id)">Delete</button></td>
                </tr>
            </tbody>
        </table>
    </div>
</div>

CreateEmployeeComponent - create-employee.component.ts

CreateEmployeeComponent is used to create and handle a new employee form data. Add the following code to it -
import { EmployeeService } from './../employee.service';
import { Employee } from './../employee';
import { Component, OnInit } from '@angular/core';

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

  employee: Employee = new Employee();
  submitted = false;

  constructor(private employeeService: EmployeeService) { }

  ngOnInit() {
  }

  newEmployee(): void {
    this.submitted = false;
    this.employee = new Employee();
  }

  save() {
    this.employeeService.createEmployee(this.employee)
      .subscribe(data => console.log(data), error => console.log(error));
    this.employee = new Employee();
  }

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

Create a template for EmployeeCreateComponent create-employee.component.html

<h3>Create Employee</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)]="employee.firstName" name="firstName">
        </div>

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

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

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

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

EmployeeDetailsComponent- employee-details.component.ts

This component shows details of employee -
import { Employee } from './../employee';
import { Component, OnInit, Input } from '@angular/core';
import { EmployeeService } from '../employee.service';
import { EmployeeListComponent } from '../employee-list/employee-list.component';

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

  @Input() employee: Employee;

  constructor(private employeeService: EmployeeService, private listComponent: EmployeeListComponent) { }

  ngOnInit() {
  }
}

Create a template for EmployeeDetailsComponent employee-details.component.html

<div *ngIf="employee">
    <div>
        <label>Name: </label> {{employee.firstName}}
    </div>
    <div>
        <label>Age: </label> {{employee.lastName}}
    </div>
    <div>
        <label>Active: </label> {{employee.emailId}}
    </div>
    <div>
        <label>Active: </label> {{employee.active}}
    </div>

    <span class="button is-small btn-primary" *ngIf='employee.active' (click)='updateActive(false)'>Inactive</span>

    <span class="button is-small btn-primary" *ngIf='!employee.active' (click)='updateActive(true)'>Active</span>

    <span class="button is-small btn-danger" (click)='deleteEmployee()'>Delete</span>

    <hr/>
</div>

AppRoutingModule - app-routing.module.ts

import { EmployeeDetailsComponent } from './employee-details/employee-details.component';
import { CreateEmployeeComponent } from './create-employee/create-employee.component';
import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { EmployeeListComponent } from './employee-list/employee-list.component';

const routes: Routes = [
  { path: '', redirectTo: 'employee', pathMatch: 'full' },
  { path: 'employees', component: EmployeeListComponent },
  { path: 'add', component: CreateEmployeeComponent },
];

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

AppComponent - app/app.component.ts

Defines the logic for the app's root component, named AppComponent. The view associated with this root component becomes the root of the view hierarchy as you add components and services to your app.
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'Angular 6 + Spring Boot 2 + Spring Data JPA + MySQL + CRUD Tutorial';
}

app/app.component.html

Defines the HTML template associated with the root AppComponent.
<div class="container">
    <h2>{{title}}</h2>
    <hr>

    <nav class="navbar navbar-expand-sm bg-dark navbar-dark">
        <!-- Links -->
        <ul class="navbar-nav">
            <li class="nav-item">
                <a routerLink="employees" class="btn btn-primary active" role="button" routerLinkActive="active">Employees</a>
            </li>
            <li class="nav-item" style="margin-left: 10px;">
                <a routerLink="add" class="btn btn-primary active" role="button" routerLinkActive="active">Add</a>
            </li>
        </ul>

    </nav>
    <router-outlet></router-outlet>
</div>

app/app.module.ts

Defines the root module, named AppModule, that tells Angular how to assemble the application. Initially declares only the AppComponent. As you add more components to the app, they must be declared here.
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 { CreateEmployeeComponent } from './create-employee/create-employee.component';
import { EmployeeDetailsComponent } from './employee-details/employee-details.component';
import { EmployeeListComponent } from './employee-list/employee-list.component';
import { HttpClientModule } from '@angular/common/http';
@NgModule({
  declarations: [
    AppComponent,
    CreateEmployeeComponent,
    EmployeeDetailsComponent,
    EmployeeListComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    FormsModule,
    HttpClientModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }
As we already started Spring boot application. Now let's run this Angular 6 application.

Running Angular 6

Run the Angular App with a command: ng serve

Output

Open browser for url http://URLalhost:4200/:

Employee List Page


Add Employee Page

Delete Employee

Note that update employee functionality is not implemented so you can take as exercise and try to implement yourself (Tip: Add an update button to the employee list page and based on employee id you can implement update functionality. Note that Rest API is already created for update employee functionality).

The source code of this article available on my GitHub repository at https://github.com/RameshMF/angular6-springboot-crud-tutorial

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