Having said that, the major question which strikes anyone who does majorly JDBC is that how does a Hibernate DAO layer look like. Without looking at a practical implementation one cannot be easily convinced to work on it. This is the only compelling reason why I intended to write The Great Hibernate Tutorial.

This tutorial is aimed at those developers who want to get a quick breifing on how to implement a DAO layer using Hibernate. This tutorial does not cover the basics of ORM nor a detailed explanation of Hibernate configurations or api. It follows on the same route as the Great Ant tutorial which many readers liked.

5 Steps to Designing a DAO in Hibernate:

1. Identify the tables which are required as entities in your project
2. Create the Hibernate Configuration file
3. Create the Hibernate entity mapping files (hbm) and entity classes
4. Make the DAO layer with the required functions
5. Test the DAO classes

Required Softwares

The versions of the various open source software’s required for the implementation are

• MySQL 5.0.5 for Windows
• MySQL ConnectorJ
• Hibernate Core 3.0
• JDK 1.5 or above
• Eclipse 3.3 or above

So lets get going with the Great Hibernate Tutorial. The steps will explain you the specific details from the code while the actual code is present in the format of links at the bottom of this tutorial. You can open the links in different tabs of your browser and then start reading the tutorial for getting a better understanding.

Step 1. Identify the tables which are required as entities in your project

For the tutorial I am designing a basic Attendance System for a company which currently has only two tables Employee and Dept. If your MySQL is not setup at the moment you may visit the tutorial on how to setup Mysql in windows XP.

 
CREATE TABLE `employee` (                                                                                       
            `psno` int(11) NOT NULL default '0',                                                                          
            `name` varchar(50) default NULL,                                                                              
            `pass` varchar(50) default NULL,                                                                              
            `proj_cd` varchar(45) NOT NULL,                                                                               
            `dept_name` varchar(45) NOT NULL,                                                                             
            PRIMARY KEY  USING BTREE (`psno`),                                                                            
            KEY `FK_employee_newfk` (`proj_cd`,`dept_name`),                                                              
            CONSTRAINT `employee_ibfk_1` FOREIGN KEY (`proj_cd`, `dept_name`) REFERENCES `dept` (`PROJ_CD`, `DEPT_NAME`)  
          ) 
 
 
CREATE TABLE `dept` (                   
          `PROJ_CD` varchar(45) NOT NULL,       
          `DEPT_NAME` varchar(45) NOT NULL,     
          `START_DATE` date default NULL,       
          `TYPE` varchar(45) default NULL,      
          PRIMARY KEY  (`PROJ_CD`,`DEPT_NAME`)  
        )

The Employee and Dept have a one to many relationship. From the DDL it is evident that Dept table has composite keys. Usually composite keys are considered evil , but I am using it just for the sake of presenting a use case of configuring composite keys in hibernate.

Step 2. Create the Hibernate Configuration file

The Hibernate configuration file is where you provide all the connection level details. It is very straightforward configuration and appears similar to your JDBC connection statements. But unlike JDBC, you can specify many more things here like caching, dialects, debug queries. One important aspect of this configuration file is providing path of hbm files. Check the following two line of XML.

<mapping resource="com/abc/entities/Employee.hbm.xml"/>     
<mapping resource="com/abc/entities/Dept.hbm.xml"/>

These lines are important. They specify the paths to your entity mapping files. Entity mapping files are those XML files which tell hibernate as to how the entity classes relate to the tables. It defines how the data should flow from class properties to the table columns. But you have to be careful in mentioning the paths to the mapping files. It is not required that the files be kept in the packages as I have done but it is considered a convention.

Step 3. Create the Hibernate entity mapping files (hbm) and entity classes

In this step we would be actually defining the mapping. I have kept all the entities in the package com.abc.entities along with the mapping files. The first element is obvious <hibernate-mapping>. Within this element you would most of the times define 3 elements: Class, ID and Property.

Class – the class for which mapping to the table is being defined

<class name="com.abc.entities.Employee" table="employee" lazy="false">

One extra attribute of the element you would notice is lazy=”false”. This is the lazy loading technique of ORM the details of which are beyond the scope of this tutorial. You may even not mention it.

ID – Primary key is an absolute must in hibernate mapped tables. Primary Keys are mapped to ID as follows

<id name="psno" column="psno">
	<generator class="assigned" />
</id>

Generator means how the primary key is populated. If it was auto generated in the table then the value should have been “auto“. The value “assigned” means we will set it in the application itself. In case of Dept, since composite key exists we should define it as

<composite-id name="deptPK" class="com.abc.entities.DeptPK">
	<key-property name="projCode" column="PROJ_CD" />
	<key-property name="deptName" column="DEPT_NAME" />
</composite-id>

Property – These are columns which would be made as properties having getters and setters in the class definition

<property name="name"/>

this would map name property of Employee class to the name column of employee table.

Associations in Hibernate

The above 3 are majorly used. Apart from that you can also mention cardinality mapping if required as follows:

<many-to-one name="dept" class="com.abc.entities.Dept">
	<column name="proj_cd" not-null="true"/>
	<column name="dept_name" not-null="true"/>
</many-to-one>

Since I have a composite key in Dept table I have mentioned two columns in the above mapping. This mapping can be read as “MANY Employees are related TO ONE Dept with help of COLUMNS proj_cd and dept_name“. These mappings are called as Associations in hibernate.

In the Dept mapping file since one dept can return multiple Employees, they would be returned in the form of a set. Hence we would have to map the set of Employee as:

<set name="employees" inverse="true">
	<key>
		<column name="proj_cd"/>
		<column name="dept_name"/>
	</key>
	<one-to-many class="com.abc.entities.Employee" />
</set>

The inverse=”true” says that the association is bidirectional which is another important concept in hibernate. In a bidirectional relationship you can reach an associated element from within one element and same applies the other way too. On the contrary you may even have unidirectional relationship in which you don’t specify mapping in the other classes.

Defining Entity classes

This is straight forward. Entity classes are simple Java Beans. You can view the class definition in the links provided at the bottom of this post. A no argument public constructor is a must in case you define a custom one.

One special case here would be for composite keys. Composite keys are defined in a separate class. After this, In the class where composite keys are required you would have to make a property of the composite-class-type.

Step 4. Make the DAO layer with the required functions

Finally we are the moment of salvation. The thing which we were waiting eagerly for implementing. The DAO layer. It is always a good practice to make a separate DAO class for holding utility functions. Hibernate requires that you always open a session before accessing the database and making transactions when you update the database. This requires repeatable lines of code.

So in order to avoid repeating ourselves its better to keep these lines of code in a DAO class as shown in the links below. Check for com.abc.dao.DAO.java. You may use the class as it is since it is a routine code. For coding your own classes to make use of the utility functions in the DAO extend your class with this DAO.

Lets have a look at AdminDAO. Since I belive in interface based implementations I have provided AdminDAO as an interface and AdminDAOHibernateImpl as its implementation which extends DAO. The code is kept simple for understanding purposes. The things worth pondering are:

In functions which do an update on the tables you have to carry the following steps:

1. begin();
2. getSession()….; // save or update
3. commit();
4. rollback();  //in case of HibernateException and throw any custom business exception if required

For fetching data you don’t need transactions so you don’t need to do the above steps. In this case you can just execute a query via the getSession() as follows:

Query q = getSession().createQuery("from Employee e inner join fetch e.dept where e.psno = :psno");
q.setString("psno", psno.toString());
Employee emp = (Employee) q.uniqueResult();

Hibernate Query Language

The above query syntax is called HQL (Hibernate Query Language). It is syntactically very similar to JDBC with the difference that HQL queries are based on objects and not on tables so the names are case sensitive and aliases to objects are a must.

In HQL, you can either fetch a single result when you know that there would be exactly one row fetched. When you know that mutiple records might be returned then you can fetch the list as follows:

Query q = getSession().createQuery("from Employee");
List<Employee> list = q.list();
return list;

Paging in Hibernate

You can obtain paging in Hibernate very easily without any additional efforts by applying a max results criteria

q.setFirstResult(firstResult);
q.setMaxResults(maxResults);

Doesn’t it feel really good. JDBC users might feel jealous at this time1

Step 5. Test the DAO classes

Now, to our final strike. The testing can be done with POJO’s. For the tutorial I had created a service layer since I usally access teh DAO layer through the service layer. So the testing was done on the service layer instead of the DAO as this application was small. You can however test out directly the DAO functions.

static void listTest(){
	try {
		List<Employee> employees = adminService.getAllEmployees();
		for(Employee emp: employees)
			System.out.println(emp.toString());
	} catch (AppException e) {
	System.out.println(e.getMessage());
	}
}

Wasn’t that a breeze? I hope that it was. Once you gain a thorough knowledge of ORM concepts then you would appreciate working with Hibernate even more. For further knowledge, I would recommend you to go through the impedence mismatch theory to know the fundamental flaws surrounding JDBC. Working with Hibernate would then be real fun.

Enjoy folks!

Resources for the tutorial

The below files are required for running the above tutorial. Copy these to your eclipse project and add the required libraries of hibernate and mysql before running the project.

Configuration
hibernate.cfg.xml

Package: com.abc.entities
com.abc.entities.Employee.java
Employee.hbm.xml
com.abc.entities.Dept.java
com.abc.entities.DeptPK.java
Dept.hbm.xml

Package: com.abc.dao
com.abc.dao.DAO.java
com.abc.dao.AdminDAO.java
com.abc.dao.AdminDAOHibernateImpl.java

Package: com.abc.service
com.abc.service.AdminService.java
com.abc.service.AdminServiceImpl.java
com.abc.service.DeptService.java
com.abc.service.DeptServiceImpl.java

Package: com.abc.exceptions
com.abc.exceptions.AppException.java

Package: com.abc.tests
com.abc.tests.DeptTest.java

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Reflection in Java is done by using using the java.lang.Class class. This class provides access to all the information within your own applications classes or even the regular java library classes. Let’s say you have a class in a package called com.tt.company.Employee then if you need the metadata of the Employee class you would have to first assign it to the Class as :

Class c = Class.forName(“com.tt.company.Employee”);

Accessing Fields, Methods and Constructors with Reflection

If you are not sure which fields and methods are declared in a class and you don’t have access to the source code then you can easily get this information by simple looping.

For example, if I wanted to access the fields and methods declared in the class Employee then its as simple as the below code.

Field[] fields = c.getFields();
 
Method[] methods = c.getMethods();
for (Field f : fields)
 
System.out.println("Field: " + f.getName());
 
for (Method m : methods)
 
System.out.println("Method:" + m.getName());

You might get some additional methods if you use the getMethods() method. This is because, the getMethods() definition also chooses those methods which are present in any of the super classes present. In this case, if Employee class does not have any super class, but still it is a subclass of Object. Hence methods defined in the Object class would also form a part of the output.

In order to avoid the methods defined in the super class you should use the getDeclaredMethods() instead.

Note: An important point worth mentioning over here is that, the loop would produce only those methods or fields which are marked public. If you don’t have a public field or method it won’t be considered. In order to loop over them, use the getDelcaredFields() or getDeclaredMethods()

Fun Things to do with Relection in Java

You can discover new techniques of programming once you feel the power of Reflection in your hands. The new techniques would include instantiation of objects dynamically, setting of values to fields and invoking methods without calling them explicitly.

Let’s take the case of a Singleton class into consideration for showing the true power of Reflection. For a Java novice, a singleton class is the one which has a private constructor. It isn’t practically true, but let’s assume that it is. Using reflection, this concept of singleton can be broken.

Here is an example of a Singleton class:

public class SingleCandidate {
 
private String name;
 
static int counter = 0;
private SingleCandidate() {
 
counter++;
 
System.out.println("Instance #" + counter);
 
}
public void showName() {
 
System.out.println(name);
 
}
 
}

A Singleton pattern dictates that only one instance of the object must be present at a given point of time in a JVM. So now, let’s take the above Singleton class for a ride with Reflection:

Class singleton = SingleCandidate.class;
 
Constructor privateConstructor =  singleton.getDeclaredConstructors()[0];
 
privateConstructor.setAccessible(true);
//This is scary
 
SingleCandidate obj = (SingleCandidate) privateConstructor.newInstance();
 
SingleCandidate obj2 = (SingleCandidate) privateConstructor.newInstance();

The code is self explanatory and you will realize that in this way you can easily create many instances of the possible candidate for a singleton class in the JVM. How fool proof was that?

Setting Values to Private Fields!

What did you learn in encapsulation? Was it making fields private and public so that private fields could be accessed only by the class in which they are declared?  Reflection can break this too.

//Even more scary
 
Field privateField = singleton.getDeclaredField("name");
 
privateField.setAccessible(true);
privateField.set(obj, "You are not a singleton anymore");
//Access private Constructor
 
System.out.println("Accessing private Constructor: " + privateConstructor.getName());//Get a private field value
 
System.out.println("Accessing private Field: " + privateField.get(obj));
//Invoke a method
 
Method method = singleton.getDeclaredMethod("showName");
 
method.invoke(obj);

Reflection with Generics

If you have tried out the above code in Eclipse you might see some warnings for the Class or Constructor usage. The warning message will be:

Class is a raw type. References to generic type Class<T> should be parameterized

Constructor is a raw type. References to generic type Constructor<T> should be parameterized

To suppress these warnings you will have to use the generic parameter “?” as follows:

Class<?> singleton = SingleCandidate.class;
 
Constructor<?> privateConstructor =  singleton.getDeclaredConstructors()[0];

The questions mark symbol is a wildcard type used in generics. This only applies only if you using Java 5 or higher versions.

Uses of reflection

Reflection is powerful technique when used appropriately. The major usage of reflection comes in when you are building your own framework, compilers or development tools in which you need access to the metadata of the classes created by end users. You surely might have already used the best products of Reflection without even knowing about it.

• JSP gets converted to Servlets using Reflection.
• The Spring framework uses Reflection to administer the references which you declare in your spring-config.xml without you explicitly instantiating any object. The whole concept of Dependency Injection (Inversion of Control) is conveniently implemented with Reflection.
• Reflection also gave birth to the concept of aspect oriented programming.

Reflection is not limited just to this post and nor Reflection is used for the purpose of breaking security. This article was aimed at showing you a direction with which you can explore Reflection more and discover new principles and techniques to build better applications.

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Future Smackdown

I am not pretty sure behind the motive of the launch however. It might have got something to do with the browser wars in particular. You see, when the giants are busy fighting a dwarf can easily run away with the bounty. If the saying is anywhere close to truth then Google Chrome just might be the next big thing we have to wait and watch. What makes me say this you might wonder. Well, Internet Explorer is busy getting decked up for its version 8 release which Microsoft must be really pushing in with its best efforts. On the other hand Firefox has had a majestic release of its version 3.0. So where does Google Chrome fit in here? Remember, they say its in beta! Gmail was too!

Google Chrome has already been stated to possess best features of Firefox and other browsers. Bloggers have been ranting about this, the most. That is true since Google Chrome may not support plugins and themes feature as of now, on which Firefox has found its enormous success. But the first question to put up front is, is Google Chrome really just another browser or a desktop application which connects to the internet. Well both say the same thing but the mention of a different memory processing model for Chrome is something which you have to consider. Google won’t be silly to reinvent the wheel. It just might be a futuristic vision of Google which we are currently witnessing on a miniature scale. Google Suggest, Maps or GMail must ring the bells as I mention this.

People may crib and rant about Google Chrome but it hasn’t hampered the success of launch down even by a pint. In fact Google has made a smart move to get as many feedbacks as possible since it has made Chrome right from scratch. Now its motive would definitely be to do a write up once again and make a surprise launch with power packed features in the next version. I can see people waiting with baited breath keeping a hawks eye on every single move Google does.

In For a Tough Competition?

Google Chrome has been launched amidst Adobe Flex going mainstream with its enterprise presence and while Silverlight is being pushed into your face. You must have some or the other time come across Flex and Silverlight applications which left your mouth wide open to see the magic they do. Can a browser reduce these giant’s market share? Why do I ask?

If you carefully notice Chrome has heavily emphasized that it is going to support the standards of web technologies like CSS, Javascript, HTML5. This means that Google Chrome would be a perfect foundation for web developers who always have been frustrated with browser dependencies when working with these web technologies. By using Chrome you might really enjoy developing a web application. This translates to more web developers being happy, more usage of standard features of Javascript, CSS and HTML, more usage of open technologies viz. Ajax, XML, JSON, leading to more usage of free tools & less use of propreitary products.

All this means, more market share for open source and Google already has set its base up front with a plethora of tools. You name it, Google Gears, GWT, Google App Engine, Google Analytics, Google Maps etc for the web developers. More standards attribute to better web applications and all which is supported by Chrome inherently. The survival of Flex or Silverlight will be a debatable issue henceforth if Google Chrome manages to captilize on its intentions.

This sounds a huge success to Google Chrome. If this falls in line, then Firefox, Internet Explorer, Safari, Opera will be competing with Chrome rather than with themselves. Google will rise to the top and rule the universe. All of this is a distant dream for me and I don’t want to sound preachy now. You do the analysis as I will wait for a surprise in the next version of Google Chrome. It might just be the next big thing, you may never know!

The things I admire in the current release of Google Chrome :

1. Full screen interface
2. Draggable tabs to windows and back into tabs
3. Neater display of history links and thumbnails of recent visits

Testing Google Chrome

The thing you might be wondering at the moment is how to distinguish Chrome from the rest of the browsers. As Google mentions, Chrome sports a different memory management model which implements each tab as a whole new process instead of a thread. On opening a tab you would notice that the task manager would have a new process listed. In order to try out Chrome’s ability with this regards you should try opening a Javascript heavy page first in browsers such as Firefox and Internet Explorer.

Heavy Javascript attributes to browser hanging which is considered often as a painful process since all the tabs hang and the browser itself has to be killed to stop the loading. As far as Chrome goes, this nature would be handled in a completely different manner since you can now directly kill a tab process from the task manager without affecting the other open tabs.

While the above concept is not much useful for the casual surfer, it will be a must for web application users in times to come, since the advent of Web 2.0 has in fact spruced up the usage of Ajax which in turn has made the web application heavy for processing. Such a model would have been required any time in near future, but with Chrome stepping the right foot at the right time you can relax down a bit now. If you are a staunch Ajax developer then Chrome surely would come to your rescue.

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I am thoroughly satisfied with Google Reader for reading my RSS feeds but I felt its been a long time I have spent on it and it has now started to bore me a bit. So I started some search for good desktop applications which would give some eye candy and also improve my productivity while learning from the feeds.

I have found one nice solution which has relieved me to some extent and which is certainly an impressive effort in the direction of web desktop integration. Its called ReadAir. It is a really nice application for feed reading and I am impressed by its potential.  The reason I liked it was because it is built on Adobe AIR. I had become a fan of Adobe AIR when I had read about it for the first time.

Seeing a live usable application built on it was something I had waited for and ReadAir has confirmed my belief that sometime later in the future we are going to see amazing applications built for the desktops but running on the web. Mozilla Prism is a yet another effort in this field.

Okay, coming back to the ReadAir. ReadAir is a desktop feed reader for reading your Google Reader feeds. The features that I can place my votes on are:

• Easy setup and login straight into Google Reader
• Direct synchronization of read posts with Google Reader
• You can star any post directly inside it which is also visible later in your Google Reader
• Add/Remove tags or feeds from within it
• It has got a very minimalistic Interface yet its pretty neat looking
• The feed post colors and fonts are soothing to the eye
• It is quick in loading.
• Clicking on the post title marks the post as read (This is better than scrolling the entire length of the post as in Google Reader)

I was satisfied by the above basic features and also expect them to improve them in the future. Since the application is in its early days, some features can be cranky at times. For example, I found the auto update feature somewhat unnecessary. It updated the application with some new features which later started to show some errors. Also, the search is not fully functional and currently ReadAir does not support keyboard shortcuts.

Leaving apart the shortcomings, the synchronization was the best part of ReadAir. At least I have got a different reader for my taste and also due to the synchronization with Google Reader, I do not have to worry about re-reading the same posts if I happen to access Google Reader from a different location. I appreciate the commendable effort put up by Adam Mcgrath for bringing this idea to life and am looking forward for addition of more features.

Try it, its nice to have a change sometimes and I would always root for web desktop applications like these. For installing ReadAir you need to have Adobe Air installed on your system. Download Adobe Air from here.

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Enter Web 2.0, and you do not have to ponder much over lost time for waiting to get hold of a tool. In this era, whatever you think of is already available online. So without fretting just google up your requirement and you would be amazed by what kind of power the internet can provide you. Coming back to the question, I responded him coolly, to use an online photo editor! He was totally baffled at the thought. If you are too, then I might as well introduce to you the best tools for photo editing online.

Online Photo Editors

The most important thing for a photo editor is to provide the features such as, cropping, editing brightness and contrast, sharpening and blurring, resize, effects and saving in multiple file formats. In a standalone editor you are most likely to find these features. But in an online environment the features will be severely limited with regards to flexibility of usage, since they are entirely web based which make them complicated to implement. I will suggest you some nifty tools which would actually make your work easier and lot more fun. Browsing across several editors I would recommend you 3 of the most liked online photo editors.

1. Phixr

Phixr is an interesting tool which does not use Flash. It is completely Ajax based and has got the potential to give the user a complete satisfaction. The most likable feature I found in this was the ability to convert your photograph into an artistic polaroid snapshot, comment bubbles and effects. It gives you the facility of direct upload of the edited photo to numerous photo sharing sites like Facebook, Flickr, Picasaweb and so on. Moreover, its free to use.

Its not a compulsion for registering for using the tool. You can try out the demo from the photo shown on the front page itself and check the features for yourselfs. Look what I could come up in a few minutes of playing with this tool.

2. SplashUp

If you are a Photoshop addict and cannot think of any other tool besides it, then you are in for a real surprise. SplashUp, earlier called Fauxto is a very well designed application which closely resembles Photoshop. It has the same look and feel and is completely made in Flash. The bonus of using SplashUp is that you can actually save your work in its own file format so that you can continue working on it later. It is the first online tool, to give a layered editing environment and work on multiple images at the same time without your browser getting hanged up. Doesn’t that sound exciting enough?

3. Picnik

Picnik one is one of my favorites and one of the most used tools while editing photos online. This is because, Flick has recently bought it, and it has been directly integrated into flickr. This makes editing your online flickr photos even more simpler. Just go to a flickr photo and choose the Edit Photo button, which opens up in a picnik editor mode. Check out for the humorous load messages it shows. The only thing I dislike about it is it takes a lot of time to load the photo which is not the case in SplashUp.

Picnik has a lot of amazing features to offer but they all do not come for free. Yet you are free to use some commonly used features with ease. Check out for fancy text effects and custom shapes. They are surely fantastic. With a tool like Picnik you wouldn’t need Photoshop around for common usages.

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Whatever the reason may be, editing a photograph is no layman’s job. Sometime people give up half way through when they do not find the required results. I recently found a something which might make your spirit rise higher when you will notice the results you get out of it. The name of the tool is Picasa. Its a tool from Google. I am sure you must have used it many time to upload your photos to the online Picasaweb. But did you ever try making collages from it. Picasa can generate some really amazing collages out of your precious photos and make them really gift worthy or send it amongst friends as a memoir.

So here’s how you can make collages out of your photos:

• Download and install Picasa if you don’t have it already from here
• When you open it Picasa will start indexing all your image folders
• Choose a folder of which you want to make a collage from
• Now carefully select the photos which are your favorite and which you want inside the collage
• Click the Collage button in the bottom bar
• Your collage will be loaded in the dialog mode
• You might not be satisfied with the collage at first so you can try one of the 2 tricks
• Press Shift and drag your mouse pointer on the collage window. You will see a change in the layout
• Keep trying till you are satisfied with a layout
• Sometimes, you might like a layout but not how the pictures are placed
• In this case press Ctrl and drag the mouse pointer. The layout will be same but the pictures will start to randomize in their placement.
• Once you are done, hit the Create Button and specify location as the “current folder”
• The collage gets created and gives you a chance to edit the collage
• Here you can try out interesting presets which include making the collage black and white or giving it a sepia tone or soft focusing it. You can have real fun over here.
• After finishing with the effect choose file > save. A backup of the original will automatically be made
• So here you are with a amazing memorabilia of your treasured photos. Sounds simple isn’t it?
  

You can do different types of collages in Picassa. The one above is called the “Picture Pile“. The other types include:

Picture Grid

Contact Sheet

You can always edit the collage features after saving it. But however there is no provision to change the photos of it later. You would have to again do the above steps for making a new collage.

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The Sessions

The session was primarily held for the developers community and less for the corporate. This provided a relief as there weren’t much marketing gimmicks being played and the speakers were purely techie guys which proved to be an onus. BEA has upgraded their Weblogic Server to version 10.2 and their Workshop too. I had worked on the BEA workshop studio and Aqualogic platform for ESB earlier. So my main interests lied in what new features these upgraded products had in their offerings. After having attending this session I am now all the more excited to work in the BEA platform.

Although many people were awestruck with the features and some felt jealous for continuing to work on the older versions at their workplace, one thing was going through the minds of many including mine. The question was as to what was the road map for these BEA products since now the acquisition by Oracle has got completed. There was a slight wave of concern over this merger on the current developers as well as for those who wanted to adopt to the BEA environment in future. Would Oracle continue to support active upgradation to these wonderful products or take away the key features from them to promote its own products? The concerns were raised higher during the session when the BEA guys told us that were not too sure of the road map either. We will have to keep fingers crossed for that.

There were 3 speakers for the entire session out of which 2 were from BEA, now christened Oracle BEA and one evangelist from Adobe. You may wonder where does Adobe form a part of the BEA endeavor? I was curious too. The curiosity was cleared by one of the BEA speakers on mentioning that Adobe had integrated its Flex platform for the BEA environment. Piggybacking for publicity you may call. But it is actually awesome.

BEA Java2SOA Revolution

The session started with the first speaker Sandeep Sonkusale who is a certified SOA Solution Architect for BEA speaking on the aspects of why an organization has to choose to the SOA infrastructure and the underlying benefits that SOA would provide. The briefing was accompanied with several high profile diagrams of how the world would be revolutionized if SOA would be adopted. I could see many people yawning to glory for this completely hypothetical preachy stuff. All were waiting for the meaty part i.e how to go about doing it. After waiting for almost 45 minutes for the briefing to get over, we felt a wave of relief when the second speaker took over with his laptop and workshop running on the presentation screen.

The second speaker was a young and smart looking Anil Sharma from the BEA product development team. His ascent was really professional. Right from the start to the end of a 2 hour long demo he had his cool even though people bombarded him with several technical queries. The demo given was on the entire new version of the BEA Workshop Studio. It is now entirely eclipse based and has all the earlier separate workshops integrated into one. This means that having workshop installed on your system you can build all the components of J2EE architecture, create web services, build beehive controls for exposing the J2EE components as services, convert these controls to web services, perform BPM process flows and later expose them too as services, connect all controls or services to Aqualogic Service Bus, convert the services to presentation portals and much much more. Phew! This entire demo was a roller coaster for me but it was real fun.

The key points which I found to be useful were the ones which the speaker was emphasizing on and on. It is not necessary that you need to create web services for making your architecture SOA enabled. You can have services like EJB services, custom control services as well web services to make an SOA. Controls are used to expose EJB’s or POJO’s as services and these are not Weblogic specific. In fact they are Apache Beehive controls which are a part of JSR 175, hence vendor lock-in can be avoided. I am not too sure if any other J2EE provider has beehive controls implementation apart from Weblogic 10.2. The interfaces and implementations of web services are done using the JSR-181 constructs.

I got to understand the use of BPM through this session. Before this, I was really hazy as to which use cases BPM really favors. Anil, through his demo explained this in a peculiar scenario. When there is a need to have an entire stateful process as a service it can be implemented as a BPM workflow through the Workshop itself. This can be further exposed as a service. Services can be further integrated into the Aqualogic Service Bus (ALSB) for implementing a transactional service workflow. It is important to note that the services integrated into the service bus must support transaction to have transactional behavior.

The major surprise to me was the merger of DSP into the Workshop. In between the workflow wherever you need a transformation of data you can easily use Data Services transformation either through XQuery or Java right within the workflow. This was something amazing.

Finally shown, were the presentation services based on Weblogic Portal platform. In order to create presentation services BEA workshop comes built in with NetUI which is the pageflow modeller for the Struts framework. Using NetUI you can create Struts JSP views directly from exposed services which further can be converted to WSRP portlets and integrated into the application portal. The most surprising aspect of the WSRP portlets is that you can access the portlet remotely too. This means that your view would be actually rendered from a remote server!

Adobe – Getting More and More Flexy

From 9:30 am to 12:15 pm the BEA guys took the center stage. The Adobe guy was nowhere to be seen. Right at 12:15 pm he popped from somewhere with his laptop and took charge. His session may have been just a 45 minute one but the impact was majestic. He transformed the crowd of almost 200 odd people to the edge of their seats and eyes wide gaping to the screen with his magical Flex demo. It was showtime for Raghu Rao, evangelist for the Flex platform for Adobe. His charisma was attention capturing and the way he breezed through the Flex demo, he left the geek’s including me, craving for more.

The presentation involved the showcase of Flex as a presentation level service for the BEA platform. He presented how Flex can be used for accessing the services exposed from the BEA environment into the presentation tier. This included the use of the commercial Adobe product LCDS which is an enterprise level Flex platform for services. If you do not want to go the paid way, you can use BlazeDS which is a open source freeware, but with limited capabilities, suitable for small applications. Using these you can make callouts to the hosted services using the Action Message Format (AMF) for remote calls.

The major source attraction proved to be the Flex demo’s, which included the Nokia Shop and a sample consumer application. The Flex charts components and 3rd party flex UI components such as coverflow component and the Flex Book component snatched away everyone’s breath.

Final Notes

Such sessions really help in accessing the direction of where technology is heading to. I am thankful to Anil and Raghu who personally cleared my confusions over some aspects offline. I felt bad to keep Raghu away from his food since I kept him bugging with my questions. He had to catch a flight to Bangalore a little while later. If you would like to evaluate the all new BEA Weblogic 10.2 platform head straight towards their eval guide for getting started and also win a 32 GB Ipod by taking this survey.

Check out the day’s captures on my picassa web album.

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According to the research done by Chris for enterprise applications, here are some of the important points which the paper elaborates:

1. Make use of the POJO approach, with lightweight frameworks like Hibernate for ORM and Spring AOP for transactional activities.
2. EJB 3 makes it possible to have your business logic sit within your POJO and also make it run outside the container which makes it really usable.
3. Implementing 3 tiers for an application which commonly include
   1. Presentation tier
   2. Business Interfaces for encapsulation + Business tier logic in classes
   3. Persistence tier for handling transactions and concurrency
4. The design should involve,
   1. Modeling your business classes appropriately
   2. Code structuring principles for easier maintenance
      

While the above points are usually very well known amongst the developer community, it helps if you know which decisions should be taken when. Design patterns which have been established over the years play a key role in making such decisions. The white paper explains a few of the design patterns which are particularly mentioned when enterprise applications are into consideration.

I would like to enumerate here, some of the different design patterns which are highlighted in the paper, according to the decisions which fall into 3 main categories.

Decision #1 – Organizing Business Logic

When you have to implement the business logic it is very important to identify the scope and the scale of the application to decide one or the other approaches as stated below,

Transaction Script Pattern:

1. Does not follow the object oriented principles
2. Methods are mapped to application request from the presentation tier, which are called as Transaction Scripts
3. Follows the procedural approach which makes classes less important and methods more important
4. Simple to implement but difficult to understand and maintain the code
5. Mainly used when business application is small

Object Oriented Approach:

1. Maps the objects from real world to the application
2. Easier to understand the application logic
3. Behavior and state are encapsulated inside the mapped objects
4. Lightweight frameworks help to apply this approach to your application.

Table Module Pattern:

1. Involves mapping of database tables to business classes
2. An object of a table includes all rows of the table rather than a single object mapped to one row
3. It suffers from the problem of maintenance.

Decision #2 – Encapsulating of Business Logic

Well designed Business applications always encapsulate logic from the view. This helps in application scalability and security, at the same time providing loose coupling between the different tiers. The patterns which can be adhered to encapsulate business logic are:

Session Facade Pattern:

1. Promotes proper encapsulation of business level logic
2. Handles transactional behavior, security and presentation tier requests
3. Does caching of objects to prevent memory overloading in case of many requests
4. Delegates requests to proper business objects
5. Was earlier implemented by using EJB 2 Session Objects
6. It is heavy on memory and time consuming for testing and development

POJO Facade Pattern:

1. Business logic encapsulated within simple POJO’s
2. Easier to develop and test and can run outside the container
3. Transactions , security and state can be maintained through AOP
4. Spring framework uses this pattern
5. Light on memory
6. Makes use of Dependency Injection for wiring the business classes instead of using JNDI
   

Exposed Domain Model Pattern:

1. Used to avoid extra code for designing the facade
2. Presentation tier can directly access data objects
   
3. Makes use of AOP to access business objects without an intermediate facade layer
4. Drawbacks include the requirement of transactions and data handling by presentation tier
5. Risky since presentation tier can directly manipulate persistent data.

Decision #3 – Database Access

The decision of accessing data is of strategic importance since IO has a major impact on application performance. So apart from making a decision on the databases and normalization it is crucial to have the best approach for accessing it from other tiers in the application. The paper emphasizes that,

Direct JDBC has drawbacks such as:

1. Boiler plate code for handling connection and fetching of data
2. Database specific SQL reduces the portability of the application
3. Maintenance of low level SQL poses problems from schema changes
4. Can be of advantage when vendor specific features have to be accessed

To overcome the disadvantages of JDBC, using a framework like the iBATIS Framework can be advantageous since:

1. Direct SQL queries can be used
   
2. Provides mapping between resultsets and Java Beans through XML descriptor

The Advantages that Persistance Frameworks offer are:

1. Mapping of data to domain objects
2. No need to write SQL code
3. Flexibility offered by configuring XML descriptors for domain level objects and data
   
4. Loading & updating of database as and when required
5. Transactions and concurrency are handled by the framework

Enterprise applications should be modeled and designed properly from the early phases itself. Without following proper approaches from the ones mentioned above can be an invitation for trouble. I hope that these approaches help the developers to come up with good designs for enterprise applications.

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The theme for this article is “Definitive Search“. It means that, instead of beating around the bush for carrying out permutations and combinations of your search queries, why not carry out the search for exactly what we are looking for. By doing this, you would become more sure of getting the most relevant articles to your queries. Notice the ‘more’ here too!

Most of the Definitive Search tricks are obtained by using the Google Advanced Operators. I would like to specify in this article as to where the operators can be utilized ‘more’ efficiently. I was myself thrilled when I tried using these operators which lead me into writing this article.

For this article I am taking a particular case study for search query optimization. So here we go…

Let us take the current situation of the Oracle BEA acquisition. One would be interested in which stories are doing rounds of it on the web. Even if you put the phrase Oracle BEA acquisition in Google you would obviously get a lot of links. Try it:

• Oracle BEA acquisition

But can you tell for sure which of the links are actually speaking specifically about this story? The answer is NO. This is because Google only searches for those articles which have these 3 words viz Oracle or BEA or acquisition.

1. Most common trick – Using Quotes

To circumvent the above analogy lets try one of the most common trick, using “” (quotes) around this phrase, since using them restricts the results to include all the above 3 words and match the articles which have them. Try it:

• “Oracle BEA acquisition”

This time the results look good since all the returned results have the 3 words either in content or their titles. But you still cannot say that the links would have some content surrounding the story. The reason is, if you consider this article itself, the 3 words are mentioned right here above. This means that even this article might get displayed in the results simply because I have used all the 3 words with the exact sequence. But there is no story about the acquisition. Get it?

2. Power of All – Using the operator allintitle

The time has come for using the powerful Google operator allintitle: This operator is used in a situation as above. Now considering the above situation, one would be urged to click on any article which has the 3 words in the title, the reason being articles with such titles are bound to be related exactly to what the title mentions. This is meaning of being definitive. The operator makes it a point to help you search the articles on the web which have the 3 words in their title. Try it:

• allintitle:Oracle BEA acquisition

3. Power of One – Using the operator intitle

Similar to the allintitle you also can use just intitle which searches for articles which have either “Oracle” or “BEA” or “Acquisition” in their content and not all the three in the title. It is good for single word searches which come in title. Let’s say that you just wanted to find some articles which mentioned all the acquisitions made by Oracle but you are not sure of them. The trick would be to use:

• intitle:Oracle acquisition

3. Digging deeper – Using the operator inURL

This one is my favorite trick. I am always looking out for current topics. The web on the other hand has got overloaded with redundant information. The problem lies here. If I search for something I won’t be so sure whether the links in the results are recent or old. Blogs help me the most is using this trick to my advantage. If you are frequent visitor of blogs then you might have noticed that they have the date of publishing right there in the URL. If you notice this blog too then the URL will have the date. Are you thinking what I am thinking?

If you have not understood then lets take the same above example. If you take the 1st example then you would notice that the search results also include old articles. In this case it also lists out BEA’s denial of Oracle merger in 2007. What we are interested is not this, but the news of the acquisition in 2008! So to try out a simple hack to this is to use the inURL operator. Try this:

• “Oracle BEA acquisition” inurl:2008

The usage of inurl:2008 lists out only those links which have been published in 2008, thus furthering making your search definitive.

4. The Perfect Match – Using the operator allinurl

This is the most definitive of all the combinations which I have mentioned above and the most efficient too. But it may not always work because having multiple words all together in an URL is rare. But still if we try this in our example:

• allinurl:Oracle BEA acquisition 2008

This is a huge filtering operator. You can judge it by the results themselves. It gives only a handful of results! Isn’t that brilliant? However, with this operator you cannot judge the quality of the returned results since it all depends on the URL is framed and not on the content! But many a times, I find it exact and helpful. Remember, you don’t have to put slashes (/) in here, just the words which you think might appear in the URL.

5. Look who is spying – Using the operator site

I use this operator sometimes for my amusement. With this operator you can search for keywords only from particular sites. For example:

• Oracle BEA acquisition site:techtracer.com

will search for the articles in this site only! It isn’t helpful much since many sites have inbuilt search feature, including Techtracer. But you can use it for finding comments which you might have made in some site! Sounds like fun!

I remember I had made a comment in DailySeoBlog a few days ago. But hey, I don’t remember which article I had made the comment on. So here is my hack for using the site operator. Just type which name you had entered while commenting. I had used my first name “nitin”. So check this out:

• nitin site:dailyseoblog.com

Amazing isn’t it? Now I know which all articles I had commented upon in the blog. So now I can easily see what people or the author has responded to my comments.

Gimme ‘more’

Using definitive tricks you can now be sure fire way of finding out exactly what you are looking for. But in the end knowing all the tricks will just won’t be helpful if you don’t apply the right tricks at the right time. It comes with habit of constantly searching for ‘more’ information. I will be continuing writing about how to improve your search queries. Many ‘more’ interesting tricks are about to come. So keep yourself subscribed to Techtracer.

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The fact is that, people miss out on these tricks since they are busy finding the keywords! In order to make them aware I will be trying to put up different tricks and their usage as per the requirement so that it becomes easier for you to get the required information in an instant.

This article is specially for the movie lovers since I am one of them. I am not “crazy” about movies but when I am keen to watch a movie I make it sure that the money is well worth spent. This is the place where Google helps me to make most of the decisions quickly. Some of these decisions include finding:

• Release date
• Cast of the movie
• Reviews of the movie
• Theatres where the movie is being aired
• Checking the schedule
• Trailers

So let me reveal the 5 most fantastic Google Movie Search tricks that I frequently use:

1. Movie Reviews

Google provides a meta parameter “movie” for finding details of movies. For example, if you want to search for the details of the movie “The Matrix” then you would have to use,

• movie: The Matrix

This would give you the information on the release year of the movie and also would show you the ratings which the movie has got from well knowns critic web sites. The interesting part of these reviews is that it even shows the number of positive reviews, neutral reviews and negative reviews, sorting by relevance, date and rating.

If you want to stop your friend from pestering you to watch a movie then make sure to check out those negative reviews! If you want to find out the details of a certain character from the view, check out links of the characters in “Frequently mentioned terms”.

2. Discover Movies

If you are left pale from you routine and want to catch up with the new releases then instead of reaching out for the different movie sites just go to,

• http://www.google.com/movies

This will of course give out the American movies. But what if you like to watch movies from your country. Of course, Google must have done something about it! And it does this, in the form of a simple domain change in the URL. For example if you want to find out Indian movies then change the domain in the URL to .co.in Here you go,

• http://www.google.co.in/movies

If this page appears blank to you then it is because of the requirement of the city name you want to see the movie in. If you are from US, just enter the zip code. This is the fantastic feature of the Google Movie search. Enter the city name in the box and watch the results. The results will show you all the theaters of the city with the list of movies which are currently being aired.

Some links worth checking out of this page are the schedules and the consolidated display of movies and theatres.

3. Movie Details

Let’s say that at this instance, you are feeling about watching any romantic movie. The first thing you would do is either ask your friend about a recommendation or walk into a shop to ask which movies are worth watching. You would not need to do this with Google Movie Search in place. All you need is to know what you are looking for. So your keywords in this case would be “romantic movies” . If you want recent ones just sort them by date.

• romantic movies

As with our earlier trick of changing domain, for searching movie by country, you would be short of luck over here. Because the results always would display english movies regardless of the domain of search. But hey, I have a trick for that too. Just a little change in the query,

• romantic hindi movies
• romantic indian movies
• action hindi movies

4. Movie Anatomy

Sometimes it happens so, that you remember a movie but fail to remember the cast of it, even who was the director of it. Google can help you quick fix these thoughts without much waste of time. You don’t have to open any website nor find the specific keywords if you don’t know whom you are searching for. For instance try this,

• director: The Incredibles
• director: Gladiator

The first line highlighted in bold spells out the directly the required answer. Fantastic, isn’t it? Similarly you can find about the entire cast of the film by just doing something similar to this,

• cast: The Incredibles
• cast: Gladiator

Remember that this might not work out in any movie. But for most of the popular movies you would be able to do the above tricks.

5. Trailers

Finally after you have done a hard work of finding the movie details, you would not want to suppress your excitement to go and actually watch the movie. If you cannot wait for long then why not add something more to it. And that is, watching the trailers!

For finding a trailer, you don’t have to visit the official movie website nor search the video sites. Just use the keywords “youtube” and “trailer” with the movie title in between. For example,

• youtube “The Matrix” trailer
• youtube “Gladiator” trailer
• youtube “The Incredibles” trailer

These searches would display two videos from youtube which have been named as trailers. These won’t necessarily be official trailers but they just the right videos which you would like to watch. Even if you don’t get the video playing option in the search results page, click the first link which would open up in youtube.

Bonus Tip: Apart from the fantastic five searches just one more bonus tip to get to the official site of any movie. Just use the keyword site besides the movie name. Examples are:

• “Resident Evil” site
• “Finding Nemo” site
• “The Matrix” site

You might ask, why I have chosen the same movie names in the examples. This is because these are some of my all time favorite movies . Similarly search for your favorite movie information with Google and enjoy it even more. Have fun!

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