Mastering Java EE Development with WildFly

Luca Stancapiano

• Publisher: Packt Publishing
• Year: 2017
• eBook ISBN: 9781787289079
• Edition: 1
• Topic: Computer Science
• Subtopic: Open Source Programming
• Index: Computer Science

Your one stop solution to create highly scalable enterprise grade Java applications with WildFly.About This Book• Master Java EE development with the latest WildFly 10 application server.• Integrate with JSF and JMS and use efficient load balancing techniques to create real-time apps• Integrate your backend JavaScript code seamlessly into Java applications Who This Book Is ForIf you are a Java developer with at least basic knowledge of Java EE, then this book is for you. No previous knowledge of WildFly is required.What You Will Learn• Configure the development environment along with native and cloud installation of WildFly• Write a DB schema and the relative entities and how to use the relationships between the entities• Analyze with examples all the java annotations to manage the EJB and the configuration to get better performances• Write different REST services through the EJB• Implement Web sockets 1.0 and know why and when use the web sockets• Work with Active MQ and write JMS clients to manage the authentication and authorization in the clients• Configure the mail server through the wildfly console• Learn how and when to use a new feature JAX-RS 2.0, which is the asynchronous call through REST• Use the new JSF features of Wildfly 10 such as Mojarra 2.2, JSF 2.2, Richfaces 4.5In DetailPacked with rich assets and APIs, Wildfly 10 allows you to create state-of-the-art Java applications. This book will help you take your understanding of Java EE to the next level by creating distributed Java applications using Wildfly.The book begins by showing how to get started with a native installation of WildFly and it ends with a cloud installation. After setting up the development environment, you will implement and work with different WildFly features, such as implementing JavaServer Pages. You will also learn how you can use clustering so that your apps can handle a high volume of data traffic. You will also work with enterprise JavaBeans, solve issues related to failover, and implement Java Message Service integration. Moving ahead, you will be working with Java Naming and Directory Interface, Java Transaction API, and use ActiveMQ for message relay and message querying. This book will also show you how you can use your existing backend JavaScript code in your application.By the end of the book, you'll have gained the knowledge to implement the latest Wildfly features in your Java applications.Style and approachEach part of this book shows you how to use different features of WildFly 10 to create enterprise grade Java applications as easily as possible.

Batches and Workflows

One good feature that started in Java EE7 is batch management. WildFly supports the implementation of this specification, the JSR 352 batch applications for the Java platform started in the 2011 and now finally integrated into the Java EE specifications.

A batch is a group of records processed as a single unit, usually without input from a user. Batches are important things for the applications because customers need the option to execute scheduled asynchronous operations for example massive data to update automatically for a date in the night.

Batches can be compared to the scheduled singletons seen in Chapter 11, Asynchronous EJB but they are organized with one scope in mind, guaranteeing the process of a large quantity of data. So the batches work in a domain different to the EJB because they don't need to be called upon by an external component. They don't need a strong security management because the batches can be used only inside the administration domain. Using the batches you have:

• No deployment descriptors
• Portability
• Reusable interfaces
• Used by multiple users
• Runtime API
• Powerful expression language
• Parallel processing

An extension of the batch is the workflow. A workflow is a set of batches that work according to a flow. The programmer is able to design a flow, deciding all the batches that the workflow must execute either on a timer decision than a process decision.

A workflow is composed by steps and jobs:

• A job represents a single process of a workflow. It is represented by a Job Specification Language (JSL) usually by an XML file. A job (with JSR 352) is a container for steps.
• A step is a domain object represented by a sequential phase of the job. A step contains all the logic and data to perform the processing. The batch specifications deliberately leave the definition of a step vague because the content depends on the application and can be defined as the developer wishes.

JBeret 1.2.1.Final is an opensource product developed by the JBoss community implementing the JSR 352. It is integrated into WildFly 10.1.0.Final.

In this chapter we will analyze, with samples, all features available in WildFly to start batches and workflows according to the following points:

• Differences between workflows and Business Process Model (BPM)
• Batch types and models
• Jobs, steps and all workflow components provided by WildFly
• Metrics of the jobs and the steps
• Batch listeners and exceptions
• Monitoring of the batches
• Deployment of the batches

Workflows and BPM

Workflows have existed for many years. Different protocols have been defined during these years. The BPM eventually became Business Process Model and Notation (BPMN).

BPMN usually provides a web console where the analyst designs the flow. The flow can then be exported and directly deployed in a application server, so it's ready to be executed. Different good open source implementations exist, such as Bonita, Activiti, and JBPM. Let's look at a sample of Activiti designed flow:

This simple flow is composed of three steps: Review Task, Document Approved, and Document Rejected. Each step executes an operation. The X (cross mark) is a decision. The process will calculate based on the direction the road will take (in this case, left or right).

The same thing can be done in WildFly now. So, what is the difference introdu...

Table of contents

• Title Page
• Copyright
• Credits
• About the Author
• About the Reviewers
• www.PacktPub.com
• Customer Feedback
• Preface
• Introducing Java EE and Configuring the Development Environment
• Working with Dependency Injection
• Persistence
• Implementing Business Logic
• Working with Distributed Transactions
• Creating REST Services
• Implementing WebSockets
• Working with Messaging
• Implementing a Mail Client
• Asynchronous REST
• Asynchronous EJB
• Batches and Workflows
• Working with Servlets and JSP
• Writing a JSF Application
• Sharing the Web Sessions
• WildFly in Cloud
• Share your Data
• Deployment
• Working with OSGi