struts framework anna paščenko. what is struts? an open source framework for building java web...
Post on 05-Jan-2016
220 Views
Preview:
TRANSCRIPT
Struts Framework
Anna Paščenko
What is Struts? An open source framework for building Java
web applications.
A Good Framework is… A defined support structure in which another
software project can be organized and developed.
A Good Framework is… A defined support structure in which another
software project can be organized and developed.
Allows to spend more time on meeting software requirements, not on more tedious low level details of providing a working system.
A Good Framework is… A defined support structure in which another
software project can be organized and developed.
Allows to spend more time on meeting software requirements, not on more tedious low level details of providing a working system.
Provides proven and reliable design patterns and code architecture to an application.
Java Web Frameworks > 50 open source frameworks only
Struts Tapestry Spring Cocoon Maverick Echo
Struts One of the most popular and widely used Java
Web frameworks: stable and mature good documentation large user community open source developed by industry experts flexible and extendable
Struts Application architectures based on the Model 2
approach, a variation of the classic Model-View-Controller (MVC) design paradigm.
MVC architecture The MVC architecture divides applications into
three layers: model, view, controller
MVC architecture The MVC architecture divides applications into
three layers: model, view, controller
Each layer handles specific tasks and has specific responsibilities to the other areas.
MVC architecture
MVC architecture A model
represents business data and business logic or operations that access and modify this
business data
notifies views when it changes provides the ability for the view to query the model
about its state provides the ability for the controller to access
application functionality
MVC architecture
MVC architecture A view
renders the contents of a model accesses data from the model and specifies how
that data should be presented updates data presentation when the model changes forwards user input to a controller
MVC architecture
MVC architecture A controller
defines application behavior an application typically has one controller for each set of
related functionality
dispatches user requests selects views for presentation interprets user inputs and maps them into actions to
be performed by the model
MVC Model 2
Struts MVC
Struts MVC Struts provides its own Controller component
and integrates with other technologies to provide the Model and the View.
Struts MVC For the Model, Struts can interact with
standard data access technologies (JDBC, EJB), most any third-party packages (Hibernate, iBATIS,
Object Relational Bridge etc.).
Struts MVC For the View, Struts works well with
JavaServer Pages, including JSTL and JSF, Velocity Templates, XSLT, etc.
Struts Architecture
Struts Controller Layer ActionServlet struts-config.xml Action ActionForward ActionForm
ActionServlet Handles requests to a Struts application.
configured as Servlet in the web.xml file
ActionServlet Handles requests to a Struts application.
configured as Servlet in the web.xml file specifies the url pattern to be handled by the servlet
ActionServlet Handles requests to a Struts application.
configured as Servlet in the web.xml file specifies the url pattern to be handled by the servlet uses the configuration defined in struts-config.xml
file to decide the destination of the request
struts-config.xml <form-beans>
describes a particular form bean, which is a JavaBean that implements the org.apache.struts.action.ActionForm class
struts-config.xml<form-beans><!-- sample form bean descriptor for a DynaActionForm
<form-beanname="logonForm“
type="org.apache.struts.action.DynaActionForm"><form-property
name="username"type="java.lang.String"/>
<form-propertyname="password"type="java.lang.String"/>
</form-bean>end sample --></form-beans>
ActionForm Encapsulates the form properties. Passed to an Action class methods as a
parameter.
struts-config.xml <form-beans>
describes a particular form bean, which is a JavaBean that implements the org.apache.struts.action.ActionForm class
<global-forwards> configures the global mappings of logical names to
mappable resources
struts-config.xml<global-forwards>
<forward
name="welcome"
path="/Welcome.do"/>
</global-forwards>
ActionForward Represents a destination to which the controller
might be directed after finishing the processing activities.
Is a return value of the Action class methods.
struts-config.xml <form-beans>
describes a particular form bean, which is a JavaBean that implements the org.apache.struts.action.ActionForm class
<global-forwards> configures the global mappings of logical names to
mappable resources <action-mappings>
contains action definitions
struts-config.xml<action-mappings>
<action
path="/Login"
type="myPackage.LoginAction"
<forward name="forwardNext"
path="/pages/NextAction.jsp"/>
</action-mappings>
ActionMapping Stores the mapping information. Passed to an Action class methods as a
parameter.
Action The Struts framework provides an abstract
Action class that you must extend for your own needs.
The ActionServlet calls the Action's execute() method to perform whatever task the Action class was meant to perform.
Within the overriden execute() method, you can put in whatever logic you need in order to fulfill the request.
Actionpublic class LoginAction extends Action {
/** * Called by the ActionServlet when the a user attempts to
login. */ public ActionForward execute(ActionMapping mapping,
ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {
// Check username and password.return mapping.findForward("forwardNext");
}}
Struts Examples Several example applications are bundled with
the Struts distribution: Blank - A simple template for starting new Struts
applications. MailReader - The original Struts example
application. Examples - Various demonstration applications
combined as separate modules.
top related