Book Image

Developing Java Applications with Spring and Spring Boot

By : Claudio Eduardo de Oliveira, Greg L. Turnquist, Alex Antonov
Book Image

Developing Java Applications with Spring and Spring Boot

By: Claudio Eduardo de Oliveira, Greg L. Turnquist, Alex Antonov

Overview of this book

Spring Framework has become the most popular framework for Java development. It not only simplifies software development but also improves developer productivity. This book covers effective ways to develop robust applications in Java using Spring. The course is up made of three modules, each one having a take-away relating to building end-to-end java applications. The first module takes the approach of learning Spring frameworks by building applications.You will learn to build APIs and integrate them with popular fraemworks suh as AngularJS, Spring WebFlux, and Spring Data. You will also learn to build microservices using Spring's support for Kotlin. You will learn about the Reactive paradigm in the Spring architecture using Project Reactor. In the second module, after getting hands-on with Spring, you will learn about the most popular tool in the Spring ecosystem-Spring Boot. You will learn to build applications with Spring Boot, bundle them, and deploy them on the cloud. After learning to build applications with Spring Boot, you will be able to use various tests that are an important part of application development. We also cover the important developer tools such as AMQP messaging, websockets, security, and more. This will give you a good functional understanding of scalable development in the Spring ecosystem with Spring Boot. In the third and final module, you will tackle the most important challenges in Java application development with Spring Boot using practical recipes. Including recipes for testing, deployment, monitoring, and securing your applications. This module will also address the functional and technical requirements for building enterprise applications. By the end of the course you will be comfortable with using Spring and Spring Boot to develop Java applications and will have mastered the intricacies of production-grade applications.
Table of Contents (34 chapters)
Title Page - Courses
Copyright and Credits - Courses
Packt Upsell - Courses

Tailoring the UI with authorization checks

With the REST endpoints locked down, it's nice to know things are secure. However, it doesn't make sense to display options in the UI that will get cut off. Instead, it's better to simply not show them. For that, we can leverage a custom Thymeleaf security rule.

Normally, we would make use of Thymeleaf's Spring Security extension. Unfortunately, the Thymeleaf team has yet to write such support for Spring Framework 5's WebFlux module. No problem! We can craft our own and register it inside the Thymeleaf engine.

For starters, we want to define an authorization scoped operation that could be embedded inside a Thymeleaf th:if="${}" expression, conditionally displaying HTML elements. We can start by adding SecurityExpressionObjectFactory to the images microservice, since that fragment of HTML is where we wish to apply it:

    public class SecurityExpressionObjectFactory 
     implements IExpressionObjectFactory { 
       private final