Consume Spring HATEOAS Rest API using AngularJS example

In this tutorial, JavaSampleApproach shows you a Spring Boot example that consumes Spring HATEOAS Rest API using AngularJS.

Contents

I. Overview
II. Practice
III. Source Code

I. Overview

1. Goal

We’ll build a Spring Boot Application in that:
– HATEOAS REST Service provides interface for interacting with Customer Database.
– Client calls API by using AngularJS, retrieves and displays:
+ Customer Data (Id, Name) with HATEOAS Links by CustomerId.
+ Order Data for Customer above.

2. Technology

– Java 1.8
– Maven 3.3.9
– Spring Tool Suite – Version 3.8.4.RELEASE
– Spring Boot: 1.5.4.RELEASE

3. Project Structure

consume-spring-hateoas-angularjs-structure

– HATEOAS REST Service:
+ Customer class extends Spring HATEOAS ResourceSupport.
+ CustomerRepository provides repository methods and custom finder methods for CustomerController to interact with Customer database.
+ CustomerController is a REST Controller which has request mapping methods for RESTful requests such as:
/{id}, /{id}/orders, /getcustomer/{id}
+ Response class defines structure for returned data of HTTP GET.

For more details about creating HATEOAS REST Service, please visit:
How to start Spring HATEOAS RestAPI with Spring Boot

– AngularJS:
+ home.jsp contains elements for GET request and display results.
+ controller() and $http.get() GET methods in get.js Javascript file.
+ WebController maps url to home.jsp page.

An example that uses AngularJS HTTP POST/GET:
How to integrate Http Angularjs with Spring MVC | Spring Boot

– Configuration for JSP page and static resources in application.properties
– Dependencies for Spring HATEOAS, WEB MVC, Tomcat in pom.xml

To know how to make application work with JSP page and static resources, please visit:
How to start with JSP page and static resource in Spring Boot

II. Practice

1. Create Spring Boot project

– Using Spring Tool Suite/Eclipse to create Project (WAR packaging), ServletInitializer and SpringBootApplication class will be created automatically.
– Add Dependencies to pom.xml file:

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-hateoas</artifactId>

</dependency>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-web</artifactId>

</dependency>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-tomcat</artifactId>

<scope>provided</scope>

</dependency>

<groupId>org.apache.tomcat.embed</groupId>

<artifactId>tomcat-embed-jasper</artifactId>

<scope>provided</scope>

</dependency>

2. Create Data Model Classes

package com.javasampleapproach.angularhateoas.model;

public class Order {

private Long id;

private String name;

public Order(Long id, String name) {

this.id = id;

this.name = name;

}

public Long getId() {

return id;

}

public void setId(Long id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

package com.javasampleapproach.angularhateoas.model;

import java.util.ArrayList;

import java.util.List;

import org.springframework.hateoas.ResourceSupport;

public class Customer extends ResourceSupport {

private Long customerId;

private String name;

private List<Order> orders;

public Customer() {

}

public Customer(Long customerId, String name, ArrayList<Order> orders) {

this.customerId = customerId;

this.name = name;

this.orders = new ArrayList<Order>(orders);

}

public Long getCustomerId() {

return customerId;

}

public void setCustomerId(Long customerId) {

this.customerId = customerId;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public List<Order> getOrders() {

return orders;

}

public void setOrders(List<Order> orders) {

this.orders = orders;

}

3. Create Message Model Class

package com.javasampleapproach.angularhateoas.message;

public class Response {

private String status;

private Object data;

public Response() {

}

public Response(String status, Object data) {

this.status = status;

this.data = data;

}

public String getStatus() {

return status;

}

public void setStatus(String status) {

this.status = status;

}

public Object getData() {

return data;

}

public void setData(Object data) {

this.data = data;

}

4. Create Repository Class

package com.javasampleapproach.angularhateoas.repo;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import org.springframework.stereotype.Repository;

import com.javasampleapproach.angularhateoas.model.Customer;

import com.javasampleapproach.angularhateoas.model.Order;

@Repository

public class CustomerRepository {

private final List<Customer> customers = new ArrayList<>();

public CustomerRepository() {

this.customers.add(new Customer(1L, "Jack",

new ArrayList<Order>(Arrays.asList(new Order(1L, "SmartPhone A"), new Order(2L, "Tablet B")))));

this.customers.add(new Customer(2L, "Adam",

new ArrayList<Order>(Arrays.asList(new Order(3L, "SmartPhone C"), new Order(4L, "Tablet D")))));

this.customers.add(new Customer(3L, "Kim",

new ArrayList<Order>(Arrays.asList(new Order(5L, "SmartPhone E"), new Order(6L, "Tablet F")))));

}

public List<Customer> findAll() {

return this.customers;

}

public Customer findOne(Long id) {

for (Customer customer : this.customers) {

if (customer.getCustomerId().equals(id)) {

return customer;

}

return null;

}

5. Create Controller Classes

package com.javasampleapproach.angularhateoas.controller;

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

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.RestController;

import com.javasampleapproach.angularhateoas.message.Response;

import com.javasampleapproach.angularhateoas.model.Customer;

import com.javasampleapproach.angularhateoas.model.Order;

import com.javasampleapproach.angularhateoas.repo.CustomerRepository;

import static org.springframework.hateoas.mvc.ControllerLinkBuilder.*;

import java.util.List;

@RestController

public class CustomerController {

@Autowired

private CustomerRepository repository;

@RequestMapping(path = "/{id}")

public Response getCustomerById(@PathVariable Long id) {

Customer customer = this.repository.findOne(id);

Response response = new Response("Done", customer);

return response;

}

@RequestMapping(path = "/{id}/orders")

public Response getOrdersForCustomer(@PathVariable Long id) {

List<Order> orders = this.repository.findOne(id).getOrders();

Response response = new Response("Done", orders);

return response;

}

@RequestMapping(value = "/getcustomer/{id}", method = RequestMethod.GET)

public Response getResource(@PathVariable Long id) {

Customer customer = this.repository.findOne(id);

customer.removeLinks();

customer.add(linkTo(CustomerController.class).slash(customer.getCustomerId()).withSelfRel());

customer.add(linkTo(methodOn(CustomerController.class).getOrdersForCustomer(customer.getCustomerId()))

.withRel("allOrders"));

Response response = new Response("Done", customer);

return response;

}

package com.javasampleapproach.angularhateoas.controller;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.servlet.ModelAndView;

@Controller

public class WebController {

@RequestMapping("/")

ModelAndView home(ModelAndView modelAndView) {

modelAndView.setViewName("home");

return modelAndView;

}

6. Configuration for JSP Page and Static Resources

Add these lines to application.properties file:

spring.mvc.view.prefix = /WEB-INF/jsps/

spring.mvc.view.suffix = .jsp

7. Add JSP Page and Javascript File

Under src/main/webapp/WEB-INF/jsps folder, add:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"

pageEncoding="ISO-8859-1"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Spring Boot HATEOAS - POST-GET AJAX Example</title>

</head>

<body>

<h1>AngularJS - consume HATEOAS</h1>

<br/>

<button id="btn-id" ng-click="getfunction()">Get Customer</button>

<p>{{getResultMessage}}</p>

<h2>Customer Information</h2>

Id: {{customer.data.customerId}}<br/>

Name: {{customer.data.name}}<br/>

Links:

<ul>

</li>

</ul>

</div>

<h2>Order Information</h2>

<strong>Order {{$index}}</strong><br/>

Id: {{order.id}}<br/>

Name: {{order.name}}

</h4></li>

</ul>

</div>

</body>

</html>

For HTTP GET, we use this method:

$http.get(‘/someUrl’, config).then(successCallback, errorCallback);

Under src/main/webapp/js folder, add:

var app = angular.module('app', []);

app.controller('getcontroller', function($scope, $http, $location) {

$scope.showCustomer = false;

$scope.showOrder = false;

$scope.getfunction = function() {

var url = $location.absUrl() + "getcustomer/" + $scope.customerId;

var orderUrl;

var config = {

headers : {

'Content-Type' : 'application/json;charset=utf-8;'

}

$http.get(url, config).then(function(response) {

if (response.data.status == "Done") {

$scope.customer = response.data;

orderUrl = $scope.customer.data.links[1].href;

$scope.showCustomer = true;

$http.get(orderUrl, config).then(function(response) {

if (response.data.status == "Done") {

$scope.orders = response.data;

$scope.showOrder = true;

} else {

$scope.getResultMessage = "Customer/Order Data Error!";

}

}, function(response) {

$scope.getResultMessage = "Fail!";

});

} else {

$scope.getResultMessage = "Customer Data Error!";

}

}, function(response) {

$scope.getResultMessage = "Fail!";

});

}

});

8. Run & Check Result

– Config maven build:
clean install
– Run project with mode Spring Boot App.
– Open Browser, enter URL:
http://localhost:8080/
consume-spring-hateoas-angularjs-request

– Fill customerID & press Get Customer button.
Customer information with Links and Order Information will appear:
consume-spring-hateoas-angularjs-response

III. Source Code

SpringBootAngularHATEOAS

By grokonez | June 16, 2017.

Consume Spring HATEOAS Rest API using AngularJS example | Spring Boot

I. Overview

1. Goal

2. Technology

3. Project Structure

II. Practice

1. Create Spring Boot project

2. Create Data Model Classes

3. Create Message Model Class

4. Create Repository Class

5. Create Controller Classes

6. Configuration for JSP Page and Static Resources

7. Add JSP Page and Javascript File

8. Run & Check Result

III. Source Code

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I. Overview

1. Goal

2. Technology

3. Project Structure

II. Practice

1. Create Spring Boot project

2. Create Data Model Classes

3. Create Message Model Class

4. Create Repository Class

5. Create Controller Classes

6. Configuration for JSP Page and Static Resources

7. Add JSP Page and Javascript File

8. Run & Check Result

III. Source Code

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