In this article by Deepak Vohra, author of the book, Advanced Java® EE Development with WildFly® you will see how to create a Java EE project and its pre-requisites.
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The objective of the EJB 3.x specification is to simplify its development by improving the EJB architecture. This simplification is achieved by providing metadata annotations to replace XML configuration. It also provides default configuration values by making entity and session beans POJOs (Plain Old Java Objects) and by making component and home interfaces redundant. The EJB 2.x entity beans is replaced with EJB 3.x entities. EJB 3.0 also introduced the Java Persistence API (JPA) for object-relational mapping of Java objects.
WildFly 8.x supports EJB 3.2 and the JPA 2.1 specifications from Java EE 7. The sample application is based on Java EE 6 and EJB 3.1. The configuration of EJB 3.x with Java EE 7 is also discussed and the sample application can be used or modified to run on a Java EE 7 project. We have used a Hibernate 4.3 persistence provider. Unlike some of the other persistence providers, the Hibernate persistence provider supports automatic generation of relational database tables including the joining of tables.
In this article, we will create an EJB 3.x project. This article has the following topics:
We need to download and install the following software:
Set the environment variables: JAVA_HOME, JBOSS_HOME, MAVEN_HOME, and MYSQL_HOME. Add %JAVA_HOME%/bin, %MAVEN_HOME%/bin, %JBOSS_HOME%/bin, and %MYSQL_HOME%/bin to the PATH environment variable. The environment settings used are C:wildfly-8.1.0.Final for JBOSS_HOME, C:Program FilesMySQLMySQL Server 5.6.21 for MYSQL_HOME, C:mavenapache-maven-3.0.5 for MAVEN_HOME, and C:Program FilesJavajdk1.7.0_51 for JAVA_HOME. Run the add-user.bat script from the %JBOSS_HOME%/bin directory to create a user for the WildFly administrator console. When prompted What type of user do you wish to add?, select a) Management User. The other option is b) Application User.
Management User is used to log in to Administration Console, and Application User is used to access applications. Subsequently, specify the Username and Password for the new user. When prompted with the question, Is this user going to be used for one AS process to connect to another AS..?, enter the answer as no. When installing and configuring the MySQL database, specify a password for the root user (the password mysql is used in the sample application).
As the application is run on WildFly 8.1, we need to create a runtime environment for WildFly 8.1 in Eclipse. Select Window | Preferences in Eclipse. In Preferences, select Server | Runtime Environment. Click on the Add button to add a new runtime environment, as shown in the following screenshot:
In New Server Runtime Environment, select JBoss Community | WildFly 8.x Runtime. Click on Next:
In WildFly Application Server 8.x, which appears below New Server Runtime Environment, specify a Name for the new runtime or choose the default name, which is WildFly 8.x Runtime. Select the Home Directory for the WildFly 8.x server using the Browse button. The Home Directory is the directory where WildFly 8.1 is installed. The default path is C:wildfly-8.1.0.Final. Select the Runtime JRE as JavaSE-1.7. If the JDK location is not added to the runtime list, first add it from the JRE preferences screen in Eclipse. In Configuration base directory, select standalone as the default setting. In Configuration file, select standalone.xml as the default setting. Click on Finish:
A new server runtime environment for WildFly 8.x Runtime gets created, as shown in the following screenshot. Click on OK:
Creating a Server Runtime Environment for WildFly 8.x is a prerequisite for creating a Java EE project in Eclipse. In the next topic, we will create a new Java EE project for an EJB 3.x application.
JBoss Tools provides project templates for different types of JBoss projects. In this topic, we will create a Java EE project for an EJB 3.x application. Select File | New | Other in Eclipse IDE. In the New wizard, select the JBoss Central | Java EE EAR Project wizard. Click on the Next button:
The Java EE EAR Project wizard gets started. By default, a Java EE 6 project is created. A Java EE EAR Project is a Maven project. The New Project Example window lists the requirements and runs a test for the requirements. The JBoss AS runtime is required and some plugins (including the JBoss Maven Tools plugin) are required for a Java EE project. Select Target Runtime as WildFly 8.x Runtime, which was created in the preceding topic. Then, check the Create a blank project checkbox. Click on the Next button:
Specify Project name as jboss-ejb3, Package as org.jboss.ejb3, and tick the Use default Workspace location box. Click on the Next button:
Specify Group Id as org.jboss.ejb3, Artifact Id as jboss-ejb3, Version as 1.0.0, and Package as org.jboss.ejb3.model. Click on Finish:
A Java EE project gets created, as shown in the following Project Explorer window. The jboss-ejb3 project consists of three subprojects: jboss-ejb3-ear, jboss-ejb3-ejb, and jboss-ejb3-web. Each subproject consists of a pom.xml file for Maven. The jboss-ejb3-ejb subproject consists of a META-INF/persistence.xml file within the src/main/resources source folder for the JPA database persistence configuration.
In this article, we learned how to create a Java EE project and its prerequisites.
Further resources on this subject: