Book Image

Spring 5.0 Cookbook

By : Sherwin John C. Tragura
Book Image

Spring 5.0 Cookbook

By: Sherwin John C. Tragura

Overview of this book

The Spring framework has been the go-to framework for Java developers for quite some time. It enhances modularity, provides more readable code, and enables the developer to focus on developing the application while the underlying framework takes care of transaction APIs, remote APIs, JMX APIs, and JMS APIs. The upcoming version of the Spring Framework has a lot to offer, above and beyond the platform upgrade to Java 9, and this book will show you all you need to know to overcome common to advanced problems you might face. Each recipe will showcase some old and new issues and solutions, right from configuring Spring 5.0 container to testing its components. Most importantly, the book will highlight concurrent processes, asynchronous MVC and reactive programming using Reactor Core APIs. Aside from the core components, this book will also include integration of third-party technologies that are mostly needed in building enterprise applications. By the end of the book, the reader will not only be well versed with the essential concepts of Spring, but will also have mastered its latest features in a solution-oriented manner.
Table of Contents (20 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Controlling concurrent user access


Concurrent access control can also be feasible in AOP since we can improvise the authentication process through the @Aspect interception. If aspects can communicate with each other through session attributes, we can utilize the existing session of the application to count the number of user accesses per account.

Getting started

Update LoginAuthAspect in order to manage the number of allowable user access privileges an account can utilize.

How to do it...

Without using Spring Security, let us simulate concurrent user control by using AOP and following these steps:

  1. Create a @Bean of Map type that will hold all usernames that are currently logged in to the application. Inject this Map in SpringContextConfig:
Configuration 
@EnableWebMvc 
@EnableAspectJAutoProxy 
@ComponentScan(basePackages="org.packt.aop.transaction") 
public class SpringContextConfig { 
   
  @Bean 
  public Map<String,Integer> authStore(){ 
    return new HashMap<>(); 
  } 
} 
  1. Update...