struts interview questions

Ques: 7 What are the parameters used in the Action.execute() method in the Struts.

Ans: The following parameters are used in the Action.execute(...) method :

  * ActionMapping : The ActionMapping class contains all of the deployment information for a particular Action object. This class is used to determine where the result of the class (that extends the Action class) will be sent once its processing is complete.

  * ActionForm : Represents the form inputs cntaining the request parameters from the view referencing this Action bean.

  * HttpServletRequest : Reference to the current Http request object.

  * HttpServletResponse : Reference to the current Http response object.

Ques: 8 Which mathod is use to forward the result to the appropriate view in the Action class in Struts?

Ans: The findForward() method is use to forward the result to the appropriate view in the Action class. This method takes the paremeter name for the view file to which the result is being forwarded.

Ques: 9 How will you tell the web application and container about your ActionServlet?

Ans: This can be accomplished by adding the following servlet definition to the web.xml file :

<servelt>

  <servlet-name>action</servlet-name>

  <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>

  <init-param>

    <param-name>config</param-name>

    <param-value>/WEB-INF/struts-config.xml</param-value>

  </init-param>

  <load-on-startup>1</load-on-startup>

</servlet>

Once you told the container about the ActionServlet you need to tell it when it should be executed by adding <servelt-mapping> element in web.xml file :

<servlet-mapping>

  <servlet-name>action</servlet-name>

  <url-pattern>*.do</url-pattern>

</servlet-mapping>

This mapping tells the web application that whenever a request is received with .do appended to the URL then the servlet named action should service the request.

Ques: 10  What are the various struts controller components?

Ans:  Four distinct Struts Controller components:

  * The ActionServlet class

  * The Action class

  * Plugins

  * RequestProcesser

Ques: 11 What is ActionServlet class in the struts controller?

Ans: The org.apache.struts.action.ActionServlet is the backbone of all Struts application. It is the main controller component that handles the client request and determines which org.apache.struts.action.Action will process each received request. It serves as an Action factory - creating specific Action classes based on the user's request.

Ques: 12 What is the entry point to ActionServlet when a request comes in.

Ans: The two main entry point into the ActionServlet are the same as any other servelt : doGet() and doPost().They call single method named process(). The struts specific behaviour begin with this mehtod.

Ques: 13 What is the process() method doing in the ActionServlet class?

Ans: The process() method gets the current RequestProcessor and invokes the RequestProcessor.process() method.The RequestProcessor.process() method is where the current request is actually serviced. This method retrieves from the struts-config.xml file, the <action> element that matches the path submitted on the request. It does this by matching the path passed in the <html:form/> tag's action element to the <action> element with the same path value.