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. The request attribute under which the servlet path information is stored for processing during a clude call. This process method then looks into the strutsconfig. The actionservlet and requestdispatcher are main players in the struts framework.
Requestprocessor, that might be directed a requestdispatcher. The only way to get it to work is to set redirecttrue, but then you lose the. The controller is responsible for intercepting and translating user input into actions to be performed by the model. Returns a requestdispatcher object that acts as a wrapper for the resource located at the given path. I further extended the requestdispatcher class and implemented my own doforward method. Struts also implement the following j2ee design patterns. The following are top voted examples for showing how to use org. Struts is based on model 2 mvc modelviewcontroller architecture. Extending struts actionservlet and requestprocessor stack overflow.
You can customize the request processing behavior by subclassing this class and overriding the methods whose behavior you are interested in changing. The controller is responsible for selecting the next view based on user input and the outcome of model operations. Requestprocessor contains the processing logic that the struts controller servlet performs as it receives each servlet request from the. It recieves the request from the client and makes decision where to send the request for further processing based on the servletconfig. If a struts application depends on the use of a custom action servlet, it must be refactored to use a custom requestprocessor instead, as outlined above, and as recommended by the struts 1. Requestdispatcher is an interface that transfers the control from current web requestdispatcher interface is define javax.
Original sevletresponse or wrapped original servletresponse not pass ed to requestdispatcher in violation of srv. I decided to not go with tiles because after looking at what the code was like when everything was compiled, i realized that it worked just like a bunch of jsp. This interface can also be used to include the content of another resource also. Actionservlet represents the controller in the modelviewcontroller mvc design pattern for web applications that is commonly known as model 2.
Therefore, you can pass data between them using request. You can also think of a requestdispatcher object as a wrapper for the resource located at a given path that is supplied as an argument to the getrequestdispatcher method. It forwards the request from one servlet to another resource such as. The instances of this classes is created dynamically as the need arises. There are two methods defined in the requestdispatcher interface. Actionservlet treats all requests made to your struts. Facing problem with filter and requestdispatcher servlets. Strutsuser using forward and include using requestprocessor. When the request object first reaches the actionservlet class then it invokes the process method of the underlying requestprocessor class. After initializing the servletconfig object requestprocessor get initialized and store the data parsed from the strutsconfig file into the requestprocessor object.
Instances of this class may be created dynamically as necessary, or configured in association with an. This nomenclature originated with a description in the javaserverpages specification, version 0. The process method of the requestprocessor uses the template method design pattern. The requestdispatcher object has two methods, include and forward. Struts does have problems forwarding between war modules in environments, such as was 5, that use multiple class loaders. Actionservlet treats all requests made to your struts application and delegates the heavy lifting stuff of handling the request to a requestprocessor object. So if you had a template page which had five tiles in it, each. Action class consists of requestprocessor which act as controller. The requestprocessor first retrieves appropriate xml block for the url. The struts requestprocessor uses the servlet api requestdispatcher forward method to have the response generated by another servletjsp. The controller is responsible for selecting the next view based on use interview questions struts interview questions. This interface is intended to wrap servlets, but a servlet container can create requestdispatcher objects to wrap any type of resource.
Struts uses the requestprocessor class to perform the processing for all requests received by the actionservlet. All interceptors are classes, which implements interceptor interface, so we must override all methods in the interceptor interface. What i did is just added these into filtermapping element for struts filter in web. Requestprocessor contains the processing logic that the actionservlet performs as it receives each servlet request from the container. What is the request processor in struts and how it. This is more or less same as struts implementation but also calls includes. The requestprocessor class is the actual place where the request processing takes place in a struts controller environment. Struts interview questions and answers for freshers and experienced in this series, we have covered all about java. Jbas4609 original sevletresponse or wrapped original.
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 strutsconfig. Command pattern using actionmapping struts provides a declarative way of specify the mapping between the servlet path in the. A resource can be another servlet, or an html file, or a jsp file, etc. The forward is processed on the server side so it cant tell the browser to go to a specific anchor. Interview questions struts interview questions roseindia. The requestdispatcher interface provides the facility of dispatching the request to another resource it may be html, servlet or jsp. Requestdispatcher are okay because the container does not intercept and.
Original sevletresponse or wrapped original servletresponse not passed to requestdispatcher in violation of srv. These examples are extracted from open source projects. It recieves the request from the client and makes decision where to send the request for further processing based on the. Requestdispatcher object, difference between include and forward method. If the action does not return null, the requestprocessor forwards or redirects to the specified resource by utilizing requestdispatcher. Actionservlet, might be directed to perform a requestdispatcher. This is the result of processing activities of an action class. What is the difference between requestprocessor and.
Start parsing or reading the data from the strutsconfig xml file by using the sax parser and store the information in the main memory. Requestprocessor contains the processing logic that the struts controller servlet performs as it receives each servlet request. The requestdispatcher interface defines an object that receives the request from client and dispatches it to the resource such as servlet, jsp, html file. The requestprocessor will use the actionforward object for invoking the next view by calling either the requestdispatcher. A requestdispatcher object can forward a clients request to a resource or include the resource itself in the response back to the client. This approach lets you customize the way each individual part of the request is processed.
Interview questions struts interview questions question. Requestprocessor contains the processing logic that the struts controller. An actionforward represents a destination to which the controller, requestprocessor, might be directed to perform a requestdispatcher. Java requestdispatcher dispatching requests in java web. In other words, everything was a static call back to the server. Behind the scenes struts will use a requestdispatcher, where the target servletjsp receives the same requestresponse objects as the original servletjsp. Since the page flow functionality in weblogic portal uses a custom action servlet, and since there can be only one action servlet in a. 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. Struts controller uses the command design pattern and the action classes use the adapter design pattern.
The action package is the core of the struts framework, providing the controller aspect of a mvc model. 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. Troubleshooting websphere commerce struts configurations. A requestdispatcher object can be used to forward a request to the resource or to include the resource in a response. Requestdispatcher in java we are going to describe requestdispatcher in java. Struts request processing flow request processor is a simple object of org. You have to do two things to implement custom request processor in struts. Hi mary, i ran into the same problem and unfortunately it isnt a bug. Each websphere commerce web module has its own struts configurations, defining base actions and globalforwards that can be difficult to debug runtime problems.
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