Latest Technical Interview Answers - 8

Latest Technical Interview Answers - 8

How to build struts in java?
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To Use Struts You need to struts related code like jar file & documentations from apache siteYou can use struts.apache.org. to download it.It is an Open source projectStruts is a framework,Provide ready to use functionality based on Model View Controller(MVC).It proviodes us the ability to develop our application by using MVC Architecture.
what is the use of findbyprimarykey()?
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The findByPrimaryKey() method works like the read() method, except that the findByPrimaryKey() method retrieves a single TxObject directly from the database using a primary key without going through a TxCursor. The primary key can be any primary key. For example, RealmId is the official primary key for the PIRealm table. Because the realm name is [...]
What is difference between Design Pattern and FrameWork.
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A Framework is a skeleton of code used for developing an application with ease.It could have used several design patterns to implement the skeleton upon which we generally build applications.Eg. Struts Framework uses MVC2 architecture, various design patterns like Front- Controller,Composite,Command patterns. Such design patterns used in the framework also helps to build applications with simplicity [...]
what is the difference between servlet context and servlet config
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Servlet context is called application object .There would be only one servlet context for a web application.This servlet context is used to get context parameters defined in web.xml .Apart from that it is used to get the information of servlet engine and to get the Request Dispatcher.RequestDispatcher rd=getServeltContext().getRequestDispatcher();ServletConfig:There would be one ServletConfig for each servlet.so [...]
What is the difference between Apache struts and Jakarta Struts?? why there are 2 names??
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Both apache struts and jakarta struts are one and the same. Struts was originally created by Craig McClanahan and was donated to the Apache Foundation in May, 2000. However after gaining prominence in the J2EE community through its evolution as a Jakarta Project, in early 2004 it become an official Apache Project. Thus there is [...]
Why we use static method in Business Logic?
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Instance methods need the class to be instantiated and are hence dependent on that particular instance of the class. Instances of an object can vary widely. In static methods, all references to it point to one copy only, and are hence independent of the instance. So any method which needs to be independent of the class [...]
Explain Struts Framework flow? and How JSP file can be processed?
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what is struts and its frame work, and also what serialisation and how many ways of serialisation is possible, and another one is what is markup interface. and what is list and linkedflist in java
What is super class of Action and ActionForm?
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Object is the super class for Action and ActionForm. Action is a class and ActionForm is an abstract class
What is ActionMapping ?
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n action mapping we specify action class for particular url ie path and diffrent target view ie forwards on to which request response will be forwarded. We also specify to which page control should go if there is validation error for ex input property of . It is also specified which form bean will correspond [...]
What is the diffrence between Apache struts and jakarta struts ?
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jakarta is a sub project of Apache. Struts used to be a Jakarta sub project. Struts is now a Apache top level project. To answer the question Jakarta Struts and Apache Struts are the same.
what is the diff between perform() and execute() method?
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As per my understanding, both perform() and execute() is the same method with different names. The prior version of struts supported “validate() and Perform()” for your action class whereas the present versions supprots “validate() and Execute()” for validation and execution of the code.
Why is the action class is singleton in nature? Isn’t this creates a bottleneck for the requests?
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No it won’t create a bottleneck as each request will be processed in separate thread. If would have created bottleneck it create separate instance for each request. We just have to make sure that we are not using any instance variable in execute method.
what is the action mapping
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An ActionMapping represents the information that the controller, RequestProcessor, knows about the mapping of a particular request to an instance of a particular Action class. The instance of ActionMapping is used to select a particular Action is passed on to that Action, thereby providing access to any custom configuration information included with the ActionMapping object
In struts why we use servlet as action controller?…
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Here u see, in servlets, we check (.do)url pattern in web.xml for each request(for each servlet) associated with url whatever u mensioned in input jsp/html page. But in case of struts no need to worry about (.do) and what type of request is coming,it can manage each request by seeing .do whatever it may be, just [...]
what is the request processor in struts? how it works?
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The RequestProcessor Class is the actual place where the request processing takes place in a Struts controller environment.When the request object first reaches the actionservlet class then it invokes the process method of the underlying RequestProcessor Class.This process method then looks into the struts-config.xml file and tries to locate the name of the action that [...]
In struts why we use jsp as view( presentation)? what happen if we use servlet as view?
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JSPs are more towards the J2EE line. In a large jsp applications, lot of java script , css(cascaded sytle sheet) , lot of more thing are applied, with the actual information. Information is required but the presentation of information is also important. It is very easy to apply all these things in JSPs , that [...]
In struts what happens if made any changes in actionservlet?
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The ActionServlet plays the role of controller wich is responsible for handling the request and selecting the correct Application Module and storing ApplicationConfig and MessageResource bundle in the request object. If we modify the ActionServlet the Controller may or may not work what happens that depends on your modification, You have not specify whether you [...]
In struts why we use jsp as presentation layer? can we use servlet as presentation layer?
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no we can not use servlet as a presentation layer in struts even though jsp converted as servlet at the back.bcos we can seperate presentation and business logic as part of jsp using java beans.but in servlets we can not seperate presentation and business logics.
what r the disadvantages of struts?
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Few Disadvantage are mentioned in the below link. Struts have disadvantages mainly on performance of the application. Especially when using advanced tag like nested-loop etc, Resulting in creating many Forms object then required.
how can container will know this is a struts application?
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in the web.xml you have to put the servlet entry(org.apache.struts.action.ActionServlet)  which is nothing but action servlet. So each request will be handled by action servlet and then it will be forwarded to assingned mapping. Mapping is all done in struts.xml. i think in this very good site people should contribute by putting good question [...]