March 2013

There were 2 posts published in March (this is page 1 of 1).

About some of the new features of Java 8 …

Just want to signal something that a lot of Java developers seem not to be aware of :
a few of the upcoming features of the JDK 8 have been available in C# for some time now.

.NET / C# Java
Lambda expressions (closures) .NET 3.5 - C# 3 - 2007 JDK 8 - 2013
Virtual extension methods .NET 3.5 - C# 3 - 2007 JDK 8 - 2013
... ... ...

C# was inspired by Java and C++ and now it kind of feels like Java 8 is catching up with C# !
But it is a good thing when the languages influence each other.
That is the case with C# and Java but that is also the case with Windows Forms / WPF + XAML and JavaFX 2 / GWT or ASP.NET MVC and Java MVC-based frameworks, etc.

That is another good reason to be open to both worlds.

[JPA 2] Adding support to WebLogic 10.3.5 for JPA 2

WebLogic 10.3.5 is JAVA EE 5 certified. However JPA 2 is not part of the JAVA EE 5 (2006) specifications, it is part of the JAVA EE 6 (2009) specifications.
So since WebLogic Server implements the Java EE 5 specification, it is not required to support JPA 2. However it is possible to add support to WebLogic 10.3.5 for JPA 2. Look no further, the answer is of course on Oracle WebLogic website: Using Oracle TopLink with Oracle WebLogic Server

A default WebLogic installation already contains the files needed :

javax.persistence_1.0.0.0_2-0-0.jar
com.oracle.jpa2support_1.0.0.0_2-0.jar

So if you make the choice to configure things manually then you do not need to install a patch.
It is just a matter of declaring a PRE_CLASSPATH environment variable in the file commEnv.cmd (Windows) or commEnv.sh (Linux) located in the WL_HOME/common/bin/ folder.

Under Windows :

@rem JPA 2 activation

set PRE_CLASSPATH=%BEA_HOME%\modules\javax.persistence_1.0.0.0_2-0-0.jar;%BEA_HOME%\modules\com.oracle.jpa2support_1.0.0.0_2-0.jar

Under Linux :

PRE_CLASSPATH=${BEA_HOME}/modules/javax.persistence_1.0.0.0_2-0-0.jar:${BEA_HOME}/modules/com.oracle.jpa2support_1.0.0.0_2-0.jar
export PRE_CLASSPATH

If you do not configure WebLogic 10.3.5 to support JPA 2 you will get an error message like this one :

nested exception is:
	javax.ejb.EJBException: what do i do: seems an odd quirk of the EJB spec.
  The exception is:java.lang.NoSuchMethodError: javax.persistence.EntityManager.createQuery(Ljava/lang/String;Ljava/lang/Class;)Ljavax/persistence/TypedQuery;;
nested exception is: javax.ejb.EJBException: what do i do: seems an odd quirk of the EJB spec.
The exception is:java.lang.NoSuchMethodError: javax.persistence.EntityManager.createQuery(Ljava/lang/String;Ljava/lang/Class;)Ljavax/persistence/TypedQuery;

javax.ejb.EJBException: what do i do: seems an odd quirk of the EJB spec.
 The exception is:java.lang.NoSuchMethodError: javax.persistence.EntityManager.createQuery(Ljava/lang/String;Ljava/lang/Class;)Ljavax/persistence/TypedQuery;

There is no need to edit the file weblogic-application.xml and to add some additional prefered application package. That one for instance works :

<?xml version="1.0" encoding="UTF-8" ?>
<weblogic-application xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:wls="http://www.bea.com/ns/weblogic/90"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/j2ee_1_4.xsd http://www.bea.com/ns/weblogic/90 http://www.bea.com/ns/weblogic/90/weblogic-application.xsd">
	<prefer-application-packages>
		<package-name>org.apache.commons.lang.*</package-name>
		<package-name>org.eclipse.persistence.*</package-name>
	</prefer-application-packages>
	<application-param>
		<param-name>webapp.encoding.default</param-name>
		<param-value>UTF-8</param-value>
	</application-param>
	<session-descriptor>
		<persistent-store-type>replicated_if_clustered</persistent-store-type>
	</session-descriptor>
</weblogic-application>