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

Applying the built-in functional interfaces


Java 1.8 also introduced some built-in functional interfaces that can be used directly in different lambda expressions. Predicate, Consumer, Supplier, and Function are some of the functional interfaces of the newly created package java.util.function, which will be highlighted in this recipe.

Getting started

Using the same Eclipse project and EmployeeServiceImpl, add the needed service methods using the pre-defined function interfaces of Java 1.8.

How to do it...

There are some built-in functional interfaces that Java 1.8 can provide in order to create services depending on the type of transactions needed to be implemented. To illustrate how to use these functional interfaces, follow these steps:

  1. Add another method to EmployeeServiceImpl that will retrieve and filter employees with an age greater than 25:
public List<Employee> getEmployeesFunc(){ 
       
     Predicate<Employee> qualifiedEmps =  
         (e) -> e.getAge() > 25;  
...