If we use servlets and jsps we have to develop our own controllers. Requestdispatcher object, difference between include and forward method. Actionservlet which intercept the request and calls requestprocessors process method for further processingrequestprocessor read xml file, find the appropriate handler and handles request. It can be use to validate the data on the users browser as well as on the server side. The requestprocessor does the following in its process method. What is the use of requestprocessor, if we are having actionservlet in struts answer sk niloufer by default struts framework provides applicationcontroller design pattern in the form of requestprocessor whereas actionservlet is a replacement of frontcontroller design pattern implementation. In fact, the struts controller retains its thread until the action is done with its processing and then it the controller decides which view jsp to forward to. For information on installing facets into an existing portal web project, see section 5.
To use struts applications and struts dependent wlp features, like struts portlets, you must add the appropriate struts facets into your portal web application, as explained in this section. What is the difference between requestprocessor and. Actionservlet treats all requests made to your struts. If we use frameworks like struts and spring internally they came with controllers. Migrating from struts 1 to struts 2 raible designs. This interface can also be used to include the content of another resource also. The action package is the core of the struts framework, providing the.
Struts basic questions and answers,struts subjective. Struts tutorial code examples struts flowhow struts works. But in current version of struts, they have replaced requestprocessor with requestdispatcher. Requestprocessor contains the processing logic that the struts controller servlet performs as it receives each servlet request from the container. Whenever it receives a request, it creates a object of the requestprocessor class i. The struts requestprocessor uses the servlet api requestdispatcher forward method to have the response generated by another servletjsp. Struts framework follow the modelviewcontroller design pattern.
Requestprocessor has become the applicationcontoller in the struts framework. Struts validator framework enables us to validate the data of both client side and server side. Struts framework provides the functionality to validate the form data. Apr 12, 2011 struts questions q how to configure struts. Struts request processing flow request processor is a simple object of org. The validator framework was developed by david winterfeldt as thirdparty addon to struts.
Frontcontroller should not have business logic involved at al. This interface is intended to wrap servlets, but a servlet container can create requestdispatcher objects to wrap any type of resource. Struts framework makes it much easier to design scalable, reliable web applications with. Oct 29, 2011 working with struts 2 interceptor with example struts on oct 29, 2011 9 comments by sivateja i n struts 1. In struts framework the controller responsibilities are implemented by several different. Note the behavior of the dispatcher, and the behavior of the request handlers that the dispatcher interacts with, is controlled via a configuration file strutsconfig. Sep 09, 2006 ravi, i hope it gives you a better understanding now. The idea is to redirect the displaying nstruction requestdispatcher. Request processor is a class which is responsible for handling request and response it is provided by struts framework if we want to customize our controller we can make in this class. Start parsing or reading the data from the strutsconfig xml file by using the sax parser and store the information in the main memory. Extending struts actionservlet and requestprocessor stack overflow. Each websphere commerce web module has its own struts configurations, defining base actions and globalforwards that can be difficult to debug runtime problems.
Interview questions struts interview questions roseindia. Every framework like struts and spring is delivered with mvc2 architecture. The validator framework comes integrated with the struts framework and can. The struts framework was originally created by craig r. When we use any framework we no need to use requestdispatcher code as well as we no need to hard code the resource path. Behind the scenes struts will use a requestdispatcher, where the target servletjsp receives the same. An actionforward represents a destination to which the controller, requestprocessor, might be directed to perform a requestdispatcher. Apr 08, 2008 requestdispatcher object, difference between include and forward method. Interview questions struts interview questions question.
So struts will create requestdispatcher for that page and call the. The requestprocessor class in the struts distribution provides a default. Hi manoj, you have mentioned one way of creating your own requestprocessor, but to locate services you should look at moduleconfig in detail. There are two methods defined in the requestdispatcher interface. The second reason is that if you ever decide to replace the struts framework with some other. The controller is responsible for selecting the next view based on user input and the outcome of model operations. It recieves the request from the client and makes decision where to send the request for further processing based on the. This is the result of processing activities of an action class. It is represented as a destination for the controller, requestprocessor, that might be directed a requestdispatcher. The actionservlet and requestdispatcher are main players in the struts framework. Requestprocessor, that might be directed a requestdispatcher.
What are the core classes of the struts frame work. What is difference between requestprocessor and request. Before being able to use struts, you must set up your jsp container so that it knows t. Struts framework provides the centralised control to throughout the web application. These examples are extracted from open source projects. Struts does not use requestdispatcher to forward control to actions. The following are top voted examples for showing how to use org. Message resources definitions files can be added to the strutsconfig. Java differecne between requestprocessor and requestdispatcher. Requestdispatcher are okay because the container does not intercept and. Struts uses the requestprocessor class to perform the processing for all requests received by the actionservlet. The controller is responsible for selecting the next view based on use.
Any struts web application contain the actionservlet configuration in web. The requestprocessor will use the actionforward object for invoking the next view by calling either the requestdispatcher. Struts flow start with actionservlet then call to process method of requestprocessor. If the application is big like any banking application etc, then you should use struts as it is very robust, makes the things simple, it also has lot of readily available security features. Struts framework emits the java scripts and it can be used validate the form data on the client browser. Action class consists of requestprocessor which act as controller. Actionservlet treats all requests made to your struts application and delegates the heavy lifting stuff of handling the request to a requestprocessor object. The servlet container creates the requestdispatcher object, which is used as a wrapper around a server resource located at a particular path or given by a particular name. Actionservlet which intercept the request and calls requestprocessors process method for further processing requestprocessor read xml file, find the appropriate handler and handles request. To use struts applications and strutsdependent wlp features, like struts portlets, you must add the appropriate struts facets into your portal web application, as explained in this section. Struts is a java mvc framework for building web applications on the j2ee platform.
The requestdispatcher interface provides the facility of dispatching the request to another resource it may be html, servlet or jsp. Command pattern using actionmapping struts provides a declarative way of specify the mapping between the servlet path in the. The controller is responsible for selecting the next view based on. A requestdispatcher is created and the forward method is invoked on it. This process method then looks into the strutsconfig. The request attribute under which the path information is stored for processing during a clude call. Mar 28, 2015 actionservlet is the only servlet in struts framework which is responsible for handling all of the requests. Load actionservlet using loadonstartup and do the following tasks. When some data validation is not present in the validator framework, then programmer can generate own validation logic, this user defined validation logic can be bind with validation framework. The instances of this classes is created dynamically as the need arises. As an alternative, try placing your object in the session scope just before a redirect, then remove the object from the session context when you are finished with it. What is the request processor in struts and how it. Create a class for example ownrequestprocessor extending class requestprocessor and override the method processpreprocess for example.
Troubleshooting websphere commerce struts configurations. What is the use of requestprocessor, if we are having. After initializing the servletconfig object requestprocessor get initialized and store the data parsed from the strutsconfig file into the requestprocessor object. What is the request processor in struts and how it works think. The requestprocessor class is the actual place where the request. Filterdispatcher is used in the early struts2 development, and its deprecated since struts 2. Struts is robust architecture and can be used for the development of application of any size. Struts flowhow struts works july 06, 2014 by mukesh kumar at 3. Now the validator framework is a part of jakarta commons project and it can be used with or without struts. You need to define a formbean in your struts config.
Struts framework is an opensource framework for developing the web applications in java ee, based on mvc2 architecture. The action package is the core of the struts framework, providing the controller aspect of a mvc model. In this case the control will be in page x till it encounters forward, after this the control will be transferred to page y. The requestprocessor class takes each request and breaks its processing down into several small tasks. Strutsbased application architecture with practical examples will be covered in chapter 5 where we have identified several strutsrelated patterns that can be used as implementation templates in implementing complex behaviors. What is the request processor in struts and how it works. You can customize the request processing behavior by subclassing this class and overriding the methods whose behavior you are interested in changing. All incoming requests are delegated by the controller to the dispatcher, which is the org. Struts does have problems forwarding between war modules in environments, such as was 5, that use multiple class loaders. Integrating existing web applications into weblogic portal. Oct 15, 2009 struts framework is an opensource framework for developing the web applications in java ee, based on mvc2 architecture.
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