Getrequestdispatcher method in servletconfig

This method will be permanently removed in a future version of the java servlet api. The difference between this method and servletcontext. This is at the end of the dopost, where i am finished and returning it. Different servlets can live in different servletcontexts, but a servlet engine can group related servlets in the same servletcontext. For constructing a requestdispatcher object, you can use either the servletrequest. There is one context per web application per java virtual machine. Using the requestdispatcher object with the include method we can include the contents of another servlet in the current servlet.

We can maintain request scope by using servletrequest or. In page x you have an include tag, this means that the control will be in the page x till it encounters include tag, after that the control will be transferred to page y. Example demonstrating usage of requestdispatcher in this example, we will show you how requestdispatcher is used to forward or include response of a resource in a servlet. Servletconfig is used to pass configuration information to servlet. The following are jave code examples for showing how to use getservletregistration of the javax. This method forwards a request from a servlet to another resource servlet, jsp file or html file on the server. An attribute allows a servlet container to give the servlet additional information not already provided by this interface. String is that this method can take a relative path. The genericservlet class implements the servlet and servletconfig interface in from mca mca501 at maharishi markandeshwar university. Servlet learning notes servletconfig, servletcontext. These examples are extracted from open source projects. Small difference in the usage exist between the two and we see later. Difference between servletconfig and servletcontext. There are two methods defined in the requestdispatcher interface.

An object implementing the requestdispatcher interface may be obtained via the following methods. In this version, this method always returns null and remains only to preserve binary compatibility. Get a requestdispatcher object use the forward method or include method of requestdispatcher. Requestdispatcher getrequestdispatcherstring path the same method belongs to both the servletrequest interface and the servletcontext interface. Requestdispatcher interface is used to receive a client request and can do one of the following two things 1 it can forward client request to some other servlet, jsp or html file. Today, we are going to understand how to forward the contents of one servlet to another servlet using the forward method of requestdispatcher object. There are three ways to obtain requestdispatcher object.

A resource can be another servlet, or an html file, or a jsp file, etc. Servlet requestdispatcher w3schools tutorialspoint. Let us see what api says about getrequestdispatcherstring path method. Now when u get the servletcontext reference, u can invoke the getcontext using the method getcontexturipath. The given path must be begin with, is interpreted relative to the server. In order to dispatch the request we need to perform these tasks.

Introduction to resquest dispatcher in servlet studytonight. The getservletcontext method and its uses with example. The server can also store extra information here in the form of string, object pairs. Another difference between the two is that path of the getrequestdispatcher string path of the servletrequest interface cannot extend outside the current servlet context whereas getrequestdispatcher string path of the servletcontext can use the getcontextstring uripath method to obtain requestdispatcher for resources in foreign contexts. Servletconfig object is used to pass information to a servlet during initialization by getting configuration information from web. The getrequestdispatcher method of servletrequest interface returns the object of requestdispatcher. New request is created for the destination resource. This method allows servlets to gain access to the context for various parts of the server, and as needed obtain requestdispatcher objects from the context. Nullpointerexception with requestdispatcher oracle community.

A requestdispatcher object can forward a clients request to a resource or include the resource itself in the response back to the client. In lieu of this method, servlets can share information using the servletcontext class and can perform shared business logic by invoking methods on common nonservlet classes. The genericservlet class implements the servlet and. This interface can also be used to include the content of another resource also. Example of servletconfig in java servlet, how to use. Check whether servlet config is null or not by calling getservletconfig. The requestdispatcher interface provides the facility of dispatching the request to another resource it may be html, servlet or jsp. In the servletconfig object, it encapsulates the relevant parameters needed to initialize the servlet program. Using the requestdispatcher object with the forward method we can forward the contents of one servlet to another servlet. This method allows servlets to gain access to the context for various parts of the.

Using getparameter method all values can also be retrieved. To understand the difference between these two methods, lets take an example. It enables one servlet to do prelude processing of a request and another resource to create the response. In this example we are retrieving all the values from the web. Servletconfig object will be available in init method of the servlet. Another difference between the two is that path of the getrequestdispatcherstring path of the servletrequest interface cannot extend outside the current servlet context whereas getrequestdispatcherstring path of the servletcontext can use the getcontextstring uripath method to obtain requestdispatcher for resources in foreign contexts. What is the defferent between getnameddispatcher and getrequestdispatcher. Returns the parameter value for the specified parameter name.

The servletcontext class provides two methods getrequestdispatcherstring. For every servlet, web container will create one servletconfig object to maintain servlet level initialization parameter. Servlet interface cannot have a constructor that accepts a servletconfig parameter. This interface defines an object that receives request from the client and sends them to any resource which can be servlet,html or jsp. Servletcontexts getcontext method servlets forum at. Returns the names of the contexts initialization parameters.

In this article, we are going to understand how to include an output from another servlet into the current servlet using the include method of requestdispatcher object. This method returns a requestdispatcher object for the resource. The servletcontext object is contained within the servletconfig object. String getservletname returns the name of this servlet instance. In this tutorial you will see that how getservletcontext method is used in servlet. It does not depend on the clients request protocol since the forward method is provided by the servlet container. Difference between forward and sendredirect in servlet. What is the difference between the getrequestdispatcherstring path method of servletrequest interface and servletcontext interface. The getrequestdispatcher method of servletrequest interface returns the object of.

Requestdispatcher is an interface that enables the servlet container to dispatch the request from a web application to another within the same context. I am sure the exception is caused by getservletcontext, since when i replace it by request, the exception disappears. Every servlet has its own servletconfig object and servlet. Introduction to servletconfig interface studytonight. Close springs web application context for the given servlet context.

What is the difference between the getrequestdispatcherstring and getnameddispatcherstring methods in the servletcontext class. There is given some commonly used methods of servletcontext interface. By using this object servlet can get its configuration information. Difference between getrequestdispatcher method of the servletrequest interface and that of the servletcontext interface. The getrequestdispatcher methods sets the folloing request attributes while transfering.

Understanding jsp line of code with getrequestdispatcher stack. Defines a set of methods that a servlet uses to communicate with its servlet container, for example, to get the mime type of a file, dispatch requests, or write to a log file. What is the defferent between getnameddispatcher and. Requstdispatcher can be get using getrequestdispacther method of servletrequest andor from the servletcontext. First u get the reference to servlet context using getservletcontext method of genericservlet or using servletconfigs getservletcontext method. Defines a set of methods that a servlet uses to communicate with a servlet engine, for example, to get the mime type of a file, locate other servlets running on the server, or write to a servlet log file. Method of genericservlet class used to return the object of servletcontext.

The requestdispatcher class enables your servlet to call another servlet from inside another servlet. Requestdispatcher is an interface that transfers the control from current web resource to another web resource such as a servlet, html, jsp on the server. A servlet instance can determine its name using servletconfig. When the web container initializes a servlet, it creates a servletconfig object for the servlet. Servletconfig creates an object of servletcontext then used it in a servlet to deploy it on the server the same as in servletconfig, but it has one important feature that makes it more useful. The following are top voted examples for showing how to use javax. We are going to describe requestdispatcher in java. The examples are extracted from open source java projects. The name may be provided via server administration, assigned in the web application deployment descriptor, or for an unregistered and thus unnamed servlet instance it will be the servlets class name. It gets the context from the servlets servletconfig object. 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. Requestdispatcher interface defines an object that receives the request from client and dispatches it to the resourcessuch as servlet, jsp, html file.