NullPointerExpection on basic EJB application in NetBeans 7.3.1 - maven

Question

I'm doing a course on Enterprise computing using Beginning Java EE 6 Platform with GlassFish 3: From Novice to Professional
Last chapter was about EJB and I've actually found it very hard to understand.
I've been trying to run one of the book's sample codes in order to try to better understand EJB but I'm getting a NullPointerException whenever I call for the EJB.
I'm using NetBeans 7.3.1 and the Maven and Glassfish versions provided with NetBeans (Maven seems to be 3.0.5, and Glassfish is 4.0)
This is the code for the main class:
package org.beginningee6.book.chapter06;
import javax.ejb.EJB;
/**
* #author Antonio Goncalves
* APress Book - Beginning Java EE 6 with Glassfish
* --
*/
public class Main {
// ======================================
// = Attributes =
// ======================================
#EJB
private static BookEJBRemote bookEJB;
// ======================================
// = Public Methods =
// ======================================
public static void main(String[] args) {
// Creates an instance of book
Book book = new Book();
book.setTitle("The Hitchhiker's Guide to the Galaxy");
book.setPrice(12.5F);
book.setDescription("Science fiction comedy series created by Douglas Adams.");
book.setIsbn("1-84023-742-2");
book.setNbOfPage(354);
book.setIllustrations(false);
book = bookEJB.createBook(book);
System.out.println("### Book created : " + book);
book.setTitle("H2G2");
book = bookEJB.updateBook(book);
System.out.println("### Book updated : " + book);
System.out.println("Execution succeeded");
}
}
Here is the persistence.xml:
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">
<persistence-unit name="chapter06PU" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<!--<jta-data-source>jdbc/__default</jta-data-source>-->
<jta-data-source>jdbc/chapter06DS</jta-data-source>
<class>org.beginningee6.book.chapter06.Book</class>
<properties>
<property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
<property name="eclipselink.logging.level" value="INFO"/>
</properties>
</persistence-unit>
</persistence>
And this is the pom.xml:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.beginningee6.book</groupId>
<artifactId>chapter06</artifactId>
<packaging>jar</packaging>
<version>2.0</version>
<name>Week5</name>
<parent>
<groupId>org.beginningee6.book</groupId>
<artifactId>chapters</artifactId>
<version>2.0</version>
</parent>
<dependencies>
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>javax.persistence</artifactId>
<version>${javax.persistence-version}</version>
</dependency>
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>eclipselink</artifactId>
<version>${eclipselink-version}</version>
</dependency>
<dependency>
<groupId>org.glassfish.extras</groupId>
<artifactId>glassfish-embedded-all</artifactId>
<version>${glassfish-version}</version>
</dependency>
</dependencies>
<!--To avoid multiple modules with Maven, here is what you need to manually do (it's not nice, but it works)
1) Comment the following section (maven-jar-plugin), package the jar, and deploy to GlassFish
2) Uncomment the following section, package the jar and run the Main class with app client -->
<build>
<!-- <plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>${plugin-jar-version}</version>
<configuration>
<archive>
<manifest>
<mainClass>org.beginningee6.book.chapter06.Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>-->
</build>
</project>
I'm getting this error:
Exception in thread "main" java.lang.NullPointerException
at this line:
book = bookEJB.updateBook(book);
Apparently Maven is giving this error:
Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec (default-cli) on project chapter06: Command execution failed. Process exited with an error: 1 (Exit value: 1) -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec (default-cli) on project chapter06: Command execution failed.
And after activating Maven's debugging option the last command line before the error is:
Executing command line: C:\Program Files (x86)\Java\jdk1.7.0_21\bin\java.exe -classpath C:\Users\Manuel_Laptop\Desktop\Week5\COIT20227LabSolWeek5\Week5\target\classes;C:\Users\Manuel_Laptop\.m2\repository\org\eclipse\persistence\javax.persistence\2.0.0\javax.persistence-2.0.0.jar;C:\Users\Manuel_Laptop\.m2\repository\org\eclipse\persistence\eclipselink\2.0.1\eclipselink-2.0.1.jar;C:\Users\Manuel_Laptop\.m2\repository\org\glassfish\extras\glassfish-embedded-all\3.0.1-b19\glassfish-embedded-all-3.0.1-b19.jar org.beginningee6.book.chapter06.Main
After going through some course tips and some forums I went and set my JAVA_HOME and M2_HOME to their respective directories but nothing worked. I even found a link to someone having an issue on the same chapter of the textbook (https://getsatisfaction.com/javaee6/topics/yet_another_chapter_6_ejb_problem) after seeing it referenced here in StackOverflow, but couldn't find anything there (didn't understand it to be honest)

Answer 1

It's not maven issue, you should set up ejb container in java SE enviroment to use EJB.
Try someithing like this
EJBContainer.createEJBContainer()
you can get complete example at http://www.oracle.com/webfolder/technetwork/tutorials/obe/java/embeddedContainerDemo/EmbeddedContainerDemo.html