Apache - Click
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By,
Anupam Mundale.
Viraj Kulkarni.
Introduction
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JEE Web Application Framework
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Method to build Web Applications without MVC and JSP’s.
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Java Language support
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Uses HTML templates and POJO’s.
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Apache Velocity Engine to support HTML templates
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Built on Java servlet API
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Open source Project (Apache license 2.0)
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Simple, easy to use, good performance and scalability
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Competing Frameworks – JSF, Tapestry, WebObjects and Apache Wicket
Click – Project Environment and Click
IDE
1) Install Click -2.3.0 and add required JAR files to the Project and deploy.
2) Click IDE
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Click IDE is an eclipse plugin for developing Click Web Applications.
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Click IDE Dependency – Eclipse 3.5.x and WTP 3.1.x
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Unzip clickide-x.x.x.x.zip and put 2 folders (plugins/ and features/) into
your ECLIPSE_HOME.
3) Click IDE Features
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Fast switching between Page classes and templates
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Project creation wizard
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Click page creation wizard
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Visual editor for the Click configuration file
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Velocity template editor
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Spring Framework and Apache Cayenne Integration
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Integrated Click documentation
Click Basics
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Org.apache.click.page – Base Class
- It contains methods and allow to handle events.
- You can override in-built methods to provide custom
functions.
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Control Components – setEventListner ()
- Example :–
Submit submitButton = new Submit("Submit Me", this, "onClick");
When the button is clicked, the event is dispatched to your custom Page class’s
onClick()
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Apache Click uses the Apache Velocity templating engine
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Templates are matched automatically with the classes that extend Page in your
application using some default mapping rules
Create Web Application using Eclipse and
import Click Libraries
1) Create Application
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Select New > Other from the Eclipse menu.
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From Select a Wizard, choose Web / Dynamic Web Project and
click Next.
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Type a name for Project Name (for example, MyFirstClick).
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Select a Target Runtime, such as Apache Tomcat 6.0.
2) Import Click Libraries
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Click File > Import.
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Select General / File System from the list and click Next.
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Browse to the directory in which you expanded the Apache Click files
and select the dist directory.
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From the list of files, select the click-{version}.jar and click-{version}extras.jar files (see Figure 2).
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Make sure the WebContent/WEB-INF/lib folder is selected in the Into
folder
Create Sample Application
Now that you have the JAR files in your WEB-INF directory, modify
the Web application's web.xml file to include the ClickServlet, which
is the single servlet used by Apache Click to dispatch events.
Continued….
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Now create a package into which your page classes will go (for
example, com.example.myfirstclick.pages). After you create the package,
create a new file called click.xml in your Web project's WEB-INF folder. Put
the name of the package you just created in the click.xml file.
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Now that your project is set up, you are ready to start writing classes that
extend the Apache Click classes.
Continued..
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Create the new class in the package you created by selecting File > New
> Other and selecting Java / Class. Make sure to
enter org.apache.click.Page as the Superclass
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Create the new HTML page—called welcome.html
Running the Sample App
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You can deploy the application by exporting the files as a Web Archive
(WAR) to the Tomcat webapps folder.
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Steps to perform in Eclipse to deploy the app –
- Click on the project and select File > Export.
- Select Web / WAR file and click Next.
-In the Destination field, browse to the Tomcat webapps
folder.
-Make sure Overwrite existing files is selected and
click Finish.
Conclusion
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Very easy to learn
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Component and Page Oriented design
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Event base programming model
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Stateless (with support for light-weight stateful components)
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Server-side Ajax support
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Exceptional performance
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Automatic form rendering and client/server side validation
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Supports Velocity, JSP or FreeMarker page rendering
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Supports Java 1.5 and up
References
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https://click.apache.org/
http://www.ibm.com/developerworks/opensource/library/
wa-apacheclick/
Thank You !!!