ozenero | Mobile & Web Programming Tutorials

In this tutorial, we show you Angular 8 Http Client & Spring Boot Server example that uses Spring JPA to do CRUD with MySQL and Angular 8 as a front-end technology to make HTTP request and receive response.

Technologies

– Java 8
– Maven 3.3.9
– Spring Tool Suite – Version 3.8.4.RELEASE
– Spring Boot: 2.1.3.RELEASE
– Angular 8
– RxJS 6

Video

Spring Boot + Angular 8 + MySQL example Overview

Spring Boot RestApis Server

spring-boot-angular-8-example-crud-mysql-spring-boot-server-architecture

Our Spring Boot Server can work with MySQL Database and provides APIs:

GET /customers/: get all customers
GET /customers/[id]: get a customer by id
GET /customers/age/[age]: find all customers by age
POST /customers/: save a customer
PUT /customers/[id]: update a customer by id
DELETE /customers/[id]: delete a customer by id
DELETE /customers/: delete all customers

Angular 8 Client

The image below shows overview about Angular Components that we will create:

Implement Spring Boot Server

Project Structure

– Customer class corresponds to entity and table customer.
– CustomerRepository is an interface extends CrudRepository, will be autowired in CustomerController for implementing repository methods and custom finder methods.
– CustomerController is a REST Controller which has request mapping methods for RESTful requests such as: getAllCustomers, postCustomer, deleteCustomer, deleteAllCustomers, findByAge, updateCustomer.
– Configuration for Spring Datasource and Spring JPA properties in application.properties
– Dependencies for Spring Boot and MySQL in pom.xml

We will keep the tutorial as simple as possible, so for post with Spring JPA details, you can visit:
How to use Spring JPA MySQL | Spring Boot

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>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

Data Model

model/Customer.java

package com.ozenero.spring.restapi.mysql.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 = "customer")
public class Customer {

  @Id
  @GeneratedValue(strategy = GenerationType.AUTO)
  private long id;

  @Column(name = "name")
  private String name;

  @Column(name = "age")
  private int age;

  @Column(name = "active")
  private boolean active;

  public Customer() {
  }

  public Customer(String name, int age) {
    this.name = name;
    this.age = age;
    this.active = false;
  }

  public long getId() {
    return id;
  }

  public void setName(String name) {
    this.name = name;
  }

  public String getName() {
    return this.name;
  }

  public void setAge(int age) {
    this.age = age;
  }

  public int getAge() {
    return this.age;
  }

  public boolean isActive() {
    return active;
  }

  public void setActive(boolean active) {
    this.active = active;
  }

  @Override
  public String toString() {
    return "Customer [id=" + id + ", name=" + name + ", age=" + age + ", active=" + active + "]";
  }
}

JPA Repository

repo/CustomerRepository.java

package com.ozenero.spring.restapi.mysql.repo;

import java.util.List;

import org.springframework.data.repository.CrudRepository;

import com.ozenero.spring.restapi.mysql.model.Customer;

public interface CustomerRepository extends CrudRepository {
  List findByAge(int age);
}

REST Controller

controller/CustomerController.java

package com.ozenero.spring.restapi.mysql.controller;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

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

import com.ozenero.spring.restapi.mysql.model.Customer;
import com.ozenero.spring.restapi.mysql.repo.CustomerRepository;

@CrossOrigin(origins = "http://localhost:4200")
@RestController
@RequestMapping("/api")
public class CustomerController {

  @Autowired
  CustomerRepository repository;

  @GetMapping("/customers")
  public ResponseEntity> getAllCustomers() {
    List customers = new ArrayList<>();
    try {
      repository.findAll().forEach(customers::add);
      
      if (customers.isEmpty()) {
        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
      }
      return new ResponseEntity<>(customers, HttpStatus.OK);
    } catch (Exception e) {
      return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
    }
  }
  
  @GetMapping("/customers/{id}")
  public ResponseEntity getCustomerById(@PathVariable("id") long id) {
    Optional customerData = repository.findById(id);

    if (customerData.isPresent()) {
      return new ResponseEntity<>(customerData.get(), HttpStatus.OK);
    } else {
      return new ResponseEntity<>(HttpStatus.NOT_FOUND);
    }
  }

  @PostMapping(value = "/customers")
  public ResponseEntity postCustomer(@RequestBody Customer customer) {
    try {
      Customer _customer = repository.save(new Customer(customer.getName(), customer.getAge()));
      return new ResponseEntity<>(_customer, HttpStatus.CREATED);
    } catch (Exception e) {
      return new ResponseEntity<>(null, HttpStatus.EXPECTATION_FAILED);
    }
  }

  @DeleteMapping("/customers/{id}")
  public ResponseEntity deleteCustomer(@PathVariable("id") long id) {
    try {
      repository.deleteById(id);
      return new ResponseEntity<>(HttpStatus.NO_CONTENT);
    } catch (Exception e) {
      return new ResponseEntity<>(HttpStatus.EXPECTATION_FAILED);
    }
  }

  @DeleteMapping("/customers")
  public ResponseEntity deleteAllCustomers() {
    try {
      repository.deleteAll();
      return new ResponseEntity<>(HttpStatus.NO_CONTENT);
    } catch (Exception e) {
      return new ResponseEntity<>(HttpStatus.EXPECTATION_FAILED);
    }

  }

  @GetMapping(value = "customers/age/{age}")
  public ResponseEntity> findByAge(@PathVariable int age) {
    try {
      List customers = repository.findByAge(age);

      if (customers.isEmpty()) {
        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
      }
      return new ResponseEntity<>(customers, HttpStatus.OK);
    } catch (Exception e) {
      return new ResponseEntity<>(HttpStatus.EXPECTATION_FAILED);
    }
  }

  @PutMapping("/customers/{id}")
  public ResponseEntity updateCustomer(@PathVariable("id") long id, @RequestBody Customer customer) {
    Optional customerData = repository.findById(id);

    if (customerData.isPresent()) {
      Customer _customer = customerData.get();
      _customer.setName(customer.getName());
      _customer.setAge(customer.getAge());
      _customer.setActive(customer.isActive());
      return new ResponseEntity<>(repository.save(_customer), HttpStatus.OK);
    } else {
      return new ResponseEntity<>(HttpStatus.NOT_FOUND);
    }
  }
}

Configuration for Spring Datasource & JPA properties

application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/testdb?useSSL=false
spring.datasource.username=root
spring.datasource.password=123456
spring.jpa.generate-ddl=true

Implement Angular 8 HTTP Client

Project Structure

We have:
– 4 components: customers-list, customer-details, create-customer, search-customer.
– 3 modules: FormsModule, HttpClientModule, AppRoutingModule.
– customer.ts: class Customer (id, firstName, lastName)
– customer.service.ts: Service for Http Client methods
– app-routing.module.ts: Routing configuration

Create Service & Components

On Project folder, run commands below:
– ng g s customer
– ng g c create-customer
– ng g c customer-details
– ng g c customers-list
– ng g c search-customers

App Module

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { CreateCustomerComponent } from './create-customer/create-customer.component';
import { CustomerDetailsComponent } from './customer-details/customer-details.component';
import { CustomersListComponent } from './customers-list/customers-list.component';
import { SearchCustomersComponent } from './search-customers/search-customers.component';

@NgModule({
  declarations: [
    AppComponent,
    CreateCustomerComponent,
    CustomerDetailsComponent,
    CustomersListComponent,
    SearchCustomersComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    FormsModule,
    HttpClientModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Add Router

app-routing.module.ts

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

import { CustomersListComponent } from './customers-list/customers-list.component';
import { CreateCustomerComponent } from './create-customer/create-customer.component';
import { SearchCustomersComponent } from './search-customers/search-customers.component';

const routes: Routes = [
  { path: '', redirectTo: 'customer', pathMatch: 'full' },
  { path: 'customer', component: CustomersListComponent },
  { path: 'add', component: CreateCustomerComponent },
  { path: 'findbyage', component: SearchCustomersComponent },
];

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

AppComponent HTML for routing:
app.component.html

<div style="padding: 20px;">
  <h1 style="color: blue">ozenero.com</h1>
  <h3>{{title}}</h3>
  <nav>
    <a routerLink="customer" class="btn btn-primary active" role="button" routerLinkActive="active">Customers</a>
    <a routerLink="add" class="btn btn-primary active" role="button" routerLinkActive="active">Add</a>
    <a routerLink="findbyage" class="btn btn-primary active" role="button" routerLinkActive="active">Search</a>
  </nav>
  <router-outlet></router-outlet>
</div>

Data Model

Create new file named customer.ts:

export class Customer {
    id: number;
    name: string;
    age: number;
    active: boolean;
}

Data Service

customer.service.ts

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';

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

  private baseUrl = 'http://localhost:8080/api/customers';

  constructor(private http: HttpClient) { }

  getCustomer(id: number): Observable {
    return this.http.get(`${this.baseUrl}/${id}`);
  }

  createCustomer(customer: any): Observable {
    return this.http.post(this.baseUrl, customer);
  }

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

  deleteCustomer(id: number): Observable {
    return this.http.delete(`${this.baseUrl}/${id}`);
  }

  getCustomersList(): Observable {
    return this.http.get(this.baseUrl);
  }

  getCustomersByAge(age: number): Observable {
    return this.http.get(`${this.baseUrl}/age/${age}`);
  }

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

Components

List of Customers

customers-list/customers-list.component.ts

import { Component, OnInit } from '@angular/core';
import { Observable } from 'rxjs';

import { CustomerService } from '../customer.service';
import { Customer } from '../customer';

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

  customers: Observable;

  constructor(private customerService: CustomerService) { }

  ngOnInit() {
    this.reloadData();
  }

  deleteCustomers() {
    this.customerService.deleteAll()
      .subscribe(
        data => {
          console.log(data);
          this.reloadData();
        },
        error => console.log('ERROR: ' + error));
  }

  reloadData() {
    this.customers = this.customerService.getCustomersList();
  }
}

customers-list/customers-list.component.html

<h3>Customers</h3>
<div *ngFor="let customer of customers | async" style="width: 300px;">
  <app-customer-details [customer]='customer'></app-customer-details>
</div>

<div>
  <button type="button" class="button btn-danger" (click)='deleteCustomers()'>Delete All</button>
</div>

Customer Details

customer-details/customer-details.component.ts

import { Component, OnInit, Input } from '@angular/core';

import { CustomerService } from '../customer.service';
import { Customer } from '../customer';
import { CustomersListComponent } from '../customers-list/customers-list.component';

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

  @Input() customer: Customer;

  constructor(private customerService: CustomerService, private listComponent: CustomersListComponent) { }

  ngOnInit() {
  }

  updateActive(isActive: boolean) {
    this.customerService.updateCustomer(this.customer.id,
      { name: this.customer.name, age: this.customer.age, active: isActive })
      .subscribe(
        data => {
          console.log(data);
          this.customer = data as Customer;
        },
        error => console.log(error));
  }

  deleteCustomer() {
    this.customerService.deleteCustomer(this.customer.id)
      .subscribe(
        data => {
          console.log(data);
          this.listComponent.reloadData();
        },
        error => console.log(error));
  }
}

customer-details/customer-details.component.html

<div *ngIf="customer">
  <div>
    <label>Name: </label> {{customer.name}}
  </div>
  <div>
    <label>Age: </label> {{customer.age}}
  </div>
  <div>
    <label>Active: </label> {{customer.active}}
  </div>
 
  <span class="button is-small btn-primary" *ngIf='customer.active' (click)='updateActive(false)'>Inactive</span>
 
  <span class="button is-small btn-primary" *ngIf='!customer.active' (click)='updateActive(true)'>Active</span>
 
  <span class="button is-small btn-danger" (click)='deleteCustomer()'>Delete</span>
 
  <hr />
</div>

Create Customer

create-customer/create-customer.component.ts

import { Component, OnInit } from '@angular/core';

import { Customer } from '../customer';
import { CustomerService } from '../customer.service';

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

  customer: Customer = new Customer();
  submitted = false;

  constructor(private customerService: CustomerService) { }

  ngOnInit() {
  }

  newCustomer(): void {
    this.submitted = false;
    this.customer = new Customer();
  }

  save() {
    this.customerService.createCustomer(this.customer)
      .subscribe(
        data => {
          console.log(data);
          this.submitted = true;
        },
        error => console.log(error));
    this.customer = new Customer();
  }

  onSubmit() {
    this.save();
  }
}

create-customer/create-customer.component.html

<h3>Create Customer</h3>
<div [hidden]="submitted" style="width: 300px;">
  <form (ngSubmit)="onSubmit()">
    <div class="form-group">
      <label for="name">Name</label>
      <input type="text" class="form-control" id="name" required [(ngModel)]="customer.name" name="name">
    </div>

    <div class="form-group">
      <label for="age">Age</label>
      <input type="text" class="form-control" id="age" required [(ngModel)]="customer.age" name="age">
    </div>

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

<div [hidden]="!submitted">
  <h4>You submitted successfully!</h4>
  <button class="btn btn-success" (click)="newCustomer()">Add</button>
</div>

Search Customers

search-customers/search-customers.component.ts

import { Component, OnInit } from '@angular/core';

import { Customer } from '../customer';
import { CustomerService } from '../customer.service';

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

  age: number;
  customers: Customer[];

  constructor(private dataService: CustomerService) { }

  ngOnInit() {
    this.age = 0;
  }

  private searchCustomers() {
    this.customers = [];
    this.dataService.getCustomersByAge(this.age)
      .subscribe(customers => this.customers = customers);
  }

  onSubmit() {
    this.searchCustomers();
  }
}

search-customers/search-customers.component.html

<h3>Find By Age</h3>
<div style="width: 300px;">
  <form (ngSubmit)="onSubmit()">
    <div class="form-group">
      <label for="lastname">Age</label>
      <input type="text" class="form-control" id="age" required [(ngModel)]="age" name="age">
    </div>

    <div class="btn-group">
      <button type="submit" class="btn btn-success">Submit</button>
    </div>
  </form>
</div>
<ul>
  <li *ngFor="let customer of customers">
    <h4>{{customer.id}} - {{customer.name}} {{customer.age}}</h4>
  </li>
</ul>

Run & Check Results

– Build and Run Spring Boot project with commandlines: mvn clean install and mvn spring-boot:run.
– Run the Angular App with command: ng serve.

– Open browser for url http://localhost:4200/

Add Customer: