wget http://download.oracle.com/otn-pub/java/jdk/7/jdk-7-linux-x64.tar.gz
tar zxvf jdk-7-linux-x64.tar.gz -C /usr/lib64/jvm/

Then we have to do some configuration.
Debian Linux has useful script to maintain different version of one programs like java called update-altenatives. So i simply use this.

update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7.0/bin/java 1065
update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.7.0/bin/javac 1065

Where 1065 is a given priority.

To check my installation i use –config paramter

update-alternatives --config java
#this prints:
There are 2 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                      Priority   Status
------------------------------------------------------------
* 0            /usr/lib/jvm/jdk1.7.0/bin/java             1065      auto mode
  1            /usr/lib/jvm/java-6-openjdk/jre/bin/java   1061      manual mode
  2            /usr/lib/jvm/jdk1.7.0/bin/java             1065      manual mode</pre>

And because 1065 is higher than 1061, the fresh installed java 7 will be used by default on my machine

java -version
#prints:
java version "1.7.0"
 Java(TM) SE Runtime Environment (build 1.7.0-b147)
 Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17, mixed mode)

Hope this save somebody some setup time.

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Every year i try some of them and  remove them after few hours. As i remember, they where resource-hungry or just bad in reverse engineering

Some weeks ago i tried ObjectAid UML Explorer Class Diagram and liked it. It could quick and easy create simple class Diagrams – just by Drag & Drop. And i had no problems with static constructors or inner classes and other stuff in the code which causes problems to another Plug-ins.

Unfortunately Object Aid Sequence Diagram are not free but cost not much for private usage. Maybe i’ll try it soon.

But first i would ask you what is your favorite Eclipse IDE Plug-in for fast and easy (e.g. partly) revers engineered UML diagrams which can be used to show some architectural details to your colleagues?

Thank you for comments!

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Web Service related changes

The new redesigned Java API for XML Web Services (JAX-WS) is the base or a middle part of a newly Java EE 6 Web service stack.  The new stack  includes JAX-WS 2.0, JAXB 2.0, and SAAJ 1.3. and is also called “integrated stack”.  JAX-WS was designed to take place of JAX-RPC. Due this also JSR-109 was updated because it describes run time architecture of JEE Web Services Stack. JAXB which provides an easy way to bind an XML schema to java and vice verse, was updated to.

The SOAP with Attachments API for Java (SAAJ) (also known as Java APIs for XML Messaging (JAXM)) provides a standard way to send XML documents over the Internet from the Java platform and was updated slightly containing now other consolidated standard.

New are JAX-RS, which provides support for RESTful Web services and JAXR which enables pull-parsing API for reading and writing XML documents. Also available in Java SE.

Web Applications related changes

In Java EE 6 we have updates of all technologies of the Web Container except JSTL. So e.g. Servlet 3.0 improves Servlet concept in pluggability and some ease of development. It’s also introduces Async Servlet, and long waited File Uploading!. Also now configuration can be done by annotations.

New a specification of Debugging Support for Other Languages 1.0
This describes standardized tools for correlating Java virtual machine byte code to source code of languages other than the Java programming language, so it would guarantee debugging possibility of everything what runs is JSR-45 certified container.

Enterprise Technologies changes

In Enterprise Application section we see some important changes and new specifications. Most famous and important is  JSR-299 Context and Dependency Injection (CDI) which is there to unify the JavaServer Faces-managed bean component model with the Enterprise JavaBeans component model to simplify the programming model and architecture of web-based applications. Look an Weld Framework as reference implementation to this.

The similar sounding Standard Dependency Injection for Java JSR-330 just define a standard and common known DI like in spring and other frameworks. Look at popular Guice DI-Framework from Google which implements JSR-330.

Bean Validation  introduces a very cool annotation based and architecture layer independent Java Bean validation.

There are also some interesting improvements in EJBs. Singleton is a new type and can be only one per container, it is also possible to use @Local Beans (Same VM) without interface. Also JPA 2.0 has advanced query possibilities and validation.

Management Technologies

Nothing special to mention here.

Java EE 6 Certified Application Server

• Oracle (former Sun) GlassFish AS 3.0.1 Full certified
• JBoss AS 6.0.0 Web Profile certification
• IBM WebSphere Application Server V8.0 (in development, Beta available) should be full certified

Please feel free to correct me or provide additional information.

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• JSR-175: A Metadata Facility for the JavaTM^TM Programming Language. Also known as Java Annotations e.g. @Deprecated or @Override.
• JSR-181: Web ServiceMetadatata for the Java Platform. This is just a set of Annotations for using with JAX-WS WebServiceses. Think of  Annotations @WebService, @WebMethod…
• JSR-101: API for XML-based RPC: JAX-RPC 1.1. Definiton of RCP call with SOAP Messages, Type Mapping between Java  and XML.
  
• JSR-109: Implementing Enterprise Web Services Definiton of WebsServices based on JAX-RPC which is now accessed by JAX-WS. That early standard defined WebServiceses for J2EE 1.4. It enabled implementation of Web-Serviceses as Endpoints over Enterprise Session Bean’s (EJB 2 generation with awful  XML descriptors).
• JSR 183: Web Services Message Security APIs
  
• JSR-224: The Java API for XML-Based Web Services (JAX-WS) 2.2
  • Final Release 05.2006 (Version 2.0 JEE 5) ,Last Maintenance 12.200Verisonon (2.2 JEE 6).
  • Current state of the art
  • Relies on its own Architecture for XML Binding JSR -222
  • Of course supports Annotations JSR -181
  • Implementations: Apache CXF, JBoss WS, JAX-WS as Sun’s Ref. Implementation
• JSR-311: JAX-RS: Java ^TM API RESTful Web Services
  • Final Release 10.2008
  • Part of JEE 6
  • AlWeb Servicesvices of REST Style jusPOJOsPOJOs
  • Mseen ssen such typical Annotations like: @Path , @GET，@PUT, @POST，@DELETE
  • Implementations: Apache CXF, Apache Wink, Resteasy as part of JBoss/Tomcat,   Jersey – Sun’s Ref. implementation.

Did I forgot something?

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Installing Java SDK

Nowadays  installing Java environment on Debian is an easy task. I used JDK 1.6. Don’t confound JDK with JRE, because bare Java Runtime Environment is not enough for running JBoss. Debian Wiki maintains (hope) a list of available java .deb packages, which are easily can be installed with your preferred way. I prefer aptitude, but apt-get of course works too.

$ aptitude install sun-java6-jdk
#or by good old apt-get.
$ apt-get install sun-java6-jdk

Installation is done after seconds. Now test your java installation with

$ java -version
# Here example result on my configuration:

java version "1.6.0_12"
Java(TM) SE Runtime Environment (build 1.6.0_12-b04)
Java HotSpot(TM) 64-Bit Server VM (build 11.2-b01, mixed mode)

If you get something like this, you’re done and your java should be already in the PATH.

Installing JBoss AS

Now let’s install  JBoss Application Server.

Preparing

Normally you are not willing  to start services (especially when they are accessed from outher machines) with root privileges. Therefore we have to define new user and group which will be used to manage JBoss.  So next line will create new group and new user with this group.

 $ groupadd jboss
 $ useradd -s /bin/bash -d /home/jboss -m -g jboss jboss

This jboss user has no password, so nobody can login with this username. If you consider to  login with jboss user,  password has to be set. Use passwd jboss command for that.

Download, Installation,  filesystem layout

Now  download desired Jboss version. I started with JBoss 5.1.0 GA, which can be download with:

$ cd /tmp # swithch to temp dir
$ wget http://sourceforge.net/projects/jboss/files/JBoss/JBoss-5.1.0.GA/jboss-5.1.0.GA.zip/download

Check also the whole list of verisons if interested. As you may noticed JBoss binaries are packaged with ZIP. So it is comfortable to use unzip tool. Maybe you have to install it first.

But before you extract  downloaded file, we have to decide, where exactly should JBoss files be placed on a  file-system. Unfortunately JBoss is not quite conform to Linux File System Hierarchy Standard per default, so there are many possibilities for a location configuration. Some of you may want to place JBoss  into /opt directory. But I prefer to split the installation a little bit and  want to start by putting  JBoss core files in /usr/local/, where local, unchangeable and read-only files usually placed. E.g. I use  /usr/local/jboss/510 as JBoss 5.1.0 GA root.  So let’s create that location and extract files into it.

mkdir /usr/local/jboss #create new jboss directroy
chown jboss:jboss /usr/local/jboss #now its belongs touser jboss and group jboss
su jboss
mkdir /usr/local/jboss/510
cd /usr/local/jboss/510
unzip /tmp/jboss-5.1.0.GA.zip

At this moment you should have new working JBoss. If you want, test it with

bin/run.sh -b 0.0.0.0

Where -b 0.0.0.0 means that JBoss is listening for every ip address of current machine.

However at this stage the installed Jboss still brakes the  Linux Filesystem Hierarchy Standard, so let’s improve this situation.

After the first start of the server used configuration will have new directories /tmp and /work . The /tmp directory contain the temporarily state of the deployed applications and /work is contains compiled jsp pages of deployed applications. Therefore both directories are of temporal character and  should be on more appropriate place according to Linux standards.

I use only a default JBoss configuration,  which is defined under <jboss_root>/server/default, so I need to do further changes only for this configuration. My decision is to put both directories to /var /tmp/jboss.:

$ mkdir /var/tmp/jboss
$ chown jboss:jboss /var/tmp/jboss/
$ su jboss
$ mkdir /var/tmp/jboss/510
$ mkdir /var/tmp/jboss/510/tmp # creating alternavtive location for tmp
$ mkdir /var/tmp/jboss/510/work # creating alternavtive location for work
$ cd /usr/local/jboss/510/server/default # switch to configuration directory if not allready here.
$ rm -R tmp # delete existing tmp directory (server should not run at this moment)
$ rm -R work # delete existing work directory
$ ln -s /var/tmp/jboss/510/tmp ./tmp # Finaly create symbolic link to new place$
$ ln -s /var/tmp/jboss/510/work ./work # Finaly create symbolic link to new place

repeat the same for /log directory. It is common to have logs at one place in /var/log
create a log directory tree e.g. /var/log/jboss/510/ and let log link to it as was shown for tmp and work directories.

After that your configuration directory should look like:

$ ls -l /usr/local/jboss/510/server/default
drwxr-xr-x  6 jboss jboss 4096 22. Mai 2009  conf
drwxr-xr-x  6 jboss jboss 4096 23. Jan 00:10 data
drwxr-xr-x 15 jboss jboss 4096 22. Mai 2009  deploy
drwxr-xr-x 12 jboss jboss 4096 22. Mai 2009  deployers
drwxr-xr-x  2 jboss jboss 4096 22. Mai 2009  lib
lrwxrwxrwx  1 jboss jboss   19 23. Jan 01:07 log -> /var/log/jboss/510/
lrwxrwxrwx  1 jboss jboss   23 23. Jan 01:13 tmp -> /var/tmp/jboss/510/tmp/
lrwxrwxrwx  1 jboss jboss   24 23. Jan 01:13 work -> /var/tmp/jboss/510/work/

And your logs are of course accessible directly at new location e.g.

tail -1000f /var/log/jboss/510/server.log

Furthermore you should deploy your applications to /srv/jboss/510 to enable this location for automatically scan and deployment,just create a link from /default/deploy/. Call it e.g. applications.:

$ ln -s /srv/jboss/510 ./usr/local/jboss/510/server/default/deploy/applications #

So applications which are placed to /srv/jboss/510 will be automatically deployed on the server.

Start JBoss on boot

First of all you need a life-cycle management script used by init. Jboss already provides some of then.  Let’s use one of Red Hat default script by adopting it a little bit. First of all copy the script to common place (feel free to ad version ti scriptname if you need or like)

$ cp /usr/local/jboss/bin/jboss_init_redhat.sh /etc/init.d/jboss

If you want to access you fresh JBoss also from other IP addresses you need to change
JBOSS_HOST line according to:

JBOSS_BIND_ADDR=${JBOSS_HOST:-"-b 0.0.0.0"}.

0.0.0.0. binds it on all IP addresses. Consider to change also other param this file to mach your personal needs. Now you can automatically create all the symbolic links used by init service.

$ update-rc.d jboss defaults

Now your Jboss will start automatically after reboot…

Additional configuration

• <jboss_root>/bin/run.conf file configures the start parameters of the server. Maybe default limits are not suitable for your applications. So check it.
• Under <jboss_root>/server/default/conf you will find some configuration files of the default server configuration. One of the interesting is of course jboss-lo4j.xml, where you can precisely define logging processing.

Questions & Suggestions

Thank you for reading this. Please feel free to provide any suggestions to the topic of JBoss installation on Linux and specially on Debian. Of course your questions are welcome too!

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As Ajaxian reports Sun has ground up rewritten the browser java Plug-in. Following was done in this rebuild.

• Improved scripting support (So java/javascript integration is better)
• Improved reliability
• Supports more powerful applets (applets can ask for more memory)
• Better windows vista support (signed applets)
• Enterprise features (run one applet in a particular JRE version)

The last point sounds very interesting for me. Earlier i have had much to do with applets, developing them for particular (old ) java version (corporate standard), but using in development newest version. So it was not always comfortable thing.

We will see what that plug-in brings!

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You can select some famous Java Scripts(AJAX) Frameworks that will be automatically added to your project.

In the created project you will find already working examples wit the core libraries you has selected in the wizard before.
Finely here is an screenshot of auto-help, and auto-suggestions. This looks real powerful at for me.

Aptana is a new IDE, the current version is 0.2.7 but it already has some interesting features and it the best for me and my Java-scripts. Aptana rapidly gains community, and i thing this project will succeed in the future, and do it already right now. With new versions of Eclipse PHP IDE and Aptana, developers have, open source web development oriented IDE of the first class!

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JunitEE

But Junit has some limitations, therefore, testing in each application server container becomes a tedious process. The JunitEE test framework addresses these limitations. This framework extends the standard JUnit so that tests can be executed in an application server container. JunitEE is configured in the J2EE Web module of a unit test application, and it uses a TestRunner to output HTML or XML test results. So according to Junitee.org there are following benefites :

• Your tests are packaged conveniently into a .war file which can easily be moved between servers; you can leave the .war file in the main .ear file and simply avoid enabling the test web application on the production server.
• Your test classes will be dynamically reloaded by the app server (assuming your server supports this).
• Your test cases look just like your production code, and can use the same beans (or whatever) you use as a facade for your EJBs.

How it works? Roughly it could be described like below, see resources for detailed examples:

1. Develop JUnit test cases
2. Create and configure a JUnitEE test modulePlace
   1. junit.jar and junitee.jar files in the project classpath by placing them in the WEB-INF/lib directory
   2. a jar file, like MyUnitTest.jar, containing your Test classes. Copy this file into the WEB-INF/lib directory too
   3. Include in the Servlet description like shown below in the web.xml deployment descriptor
3. Deploy and execute test cases on the Application Server.

{[.xml1 /enzymes/xml.php]}

Resources

1. New features in Junit 4
2. JunitEE Tutorial
3. Other Junit Extensions for J2EE
4. An extended example from IBM

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The Java Persistence API provides a POJO persistence model for object-relational mapping. The Java Persistence API was developed by the EJB 3.0 software expert group as part of JSR 220, but its use is not limited to EJB software components. It can also be used directly by web applications and application clients, and even outside the Java EE platform, for example, in Java SE applications

So let’s look a bit deeper into the features of new API.

Persistence is dealing with entities. An Entitiy is a lightweight domain specific object (in java) that sometimes should be stored to persistent storage of some kind (e.g. Relational Database).  Typically an entity is represented by a Databae table in a relational databases and each entity instance corresponds with a row in that table.

In the Java Persistence API,  persistent state of an entity is represented either through persistent fields or persistent properties. These fields  use object-relational mapping annotations to map the entities and entity relationships to the relational data in the underlying data store.

So Entities are marked with the @Entity (javax.persistence.Entity) annotation and the entity-class should implement Serializable interface. Further requirements for entitiy classes can be found in the Java EE 5 Tutorial.

Here is  just little examle of Persisten entitiy “User”.

package de.holbreich.chopping;
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.Table;
import javax.persistence.Column;
import javax.persistence.Id;

@Entity
@Table (name="User")
public class Userimplements Serializable {
 @Id
 @Column(name="id", nullable=false)
 private String userId;

 @Column(name="Username")
 private String username;

 @Column(name="Firstname")
 private String firstname

 public void setUserId(String userId){
 this.userId= userId;
 }

 public String getUserId() {
 return this.userId;
 }

 public void setUsername(String username) {
 this.username=username;
 }

 public String getUsername() {
 return this.username;
 }
...
}

If the entity name is the same as that of the table name, @Table is not required. The same with @Column Attribute. Not Persistent Fields or methods should be marked with @Transient. Here more Information about persistent field and properties and especially Primary Keys.
So far its quite simple.

Entities can have relations to each other. Java Persistence API knows four types of multiplicities: one-to-one, one-to-many, many-to-one, and many-to-many, which are marked with appropriate anotations. Furthermore relationships can be unidirectional or bidirectional. In a unidirectional relationship, only one entity has a relationship field or property that refers to the other. Read more about it.

This looks really interesting to me. But it gone to be better then, the Java Persistence API has an important new feature that was not covered bu SUN before: support for inheritance and polymorphism. An entity may inherit from another entity class. By default, the queries are polymorphic and are applicable against the entire entity hierarchy. Read more about inheritance posibilities.

An finely there is a new and better Query language

Queries and query language

The Java Persistence query language (JPQL) is an extension of the EJB QL, but overcomes EJB QL’s limitations and provides more features such as:

• Bulk update and delete operations
• Join operations
• Group-by operations
• Having operations
• Projection and sub-queries
• Support for dynamic queries
• Use of named parameters (named parameters are parameters in a query that are prefixed with a colon (:))

More on JPQL in the Tutorial

Management of entities

Entities are managed by the entity manager. The entity manager is represented by javax.persistence.EntityManager instances. Each EntityManager instance is associated with a persistence context. A persistence context is a set of managed entity instances that exist in a particular data store and defines the scope under which particular entity instances are created, persisted, and removed.

As expected the are two kinds of managers an container managed and one application managed.
With a container-managed entity manager, an EntityManager instance’s persistence context is automatically propagated by the container to all application components that use the EntityManager instance within a single Java Transaction Architecture (JTA) transaction.

@PersistenceContext(unitName="user")
EntityManager em;

With application-managed entity managers, on the other hand, the persistence context is not propagated to application components, and the life-cycle of EntityManager instances is managed by the application.

@PersistenceUnit(unitName="user")
EntityManagerFactory emf;
EntityManager em = emf.createEntityManager();

Persistent context is described in persistense.xml file

Conclusion

I thik the Java Persistence API is an real cool standard, hope start use it soon. Here are the key features of it summarized:

• Standardizes the persistence API for the Java platform
• Brings simplification through a simple POJO-based persistence model
• Annotations should makes entity coding and deployment easier
• And of course features like support for inheritance and polymorphism, simplistic entity relationship declaration bring the whole thing to new level.
• Advantages of JPQL

Furthermore Java Persistence API can be used for Java SE environments too. This is possible because of the Java Persistence API’s support outside the EJB container.

1. Java Persistence API on java.sun.com
2. Java Persistence API in the Java EE 5 Tototial
3. Good Article goes detailed on inheritance at JavaWorld
4. Extended fetures in Examples of using Persistence API in EJB tier
   
5. Using Persistens with JSF
6. Java WebStart Persistence

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