Calling another web resources

In this tutorial you will learn how a web component call to another web resources.

Calling another web resources

In this tutorial you will learn how a web component call to another web resources.

Calling another web resources

Calling another web resources

In this tutorial you will learn how a web component call to another web resources.

There can another web resources be called by the web components in both direct and indirect way. A web resource that a web component has called is an indirect way of calling by including an URL, this URL indicates the another web component which content will be returned to a client. However a web component calls another web resources directly during its execution, it can be called by either embedding content or by forwarding a request to another resource.

To call a resource it should be available on server, so it is required to get first the RequestDispatcher object. You can get the object of RequestDispatcher by using the getRequestDispatcher("URL") method. This method will return null if either the requested resource is not available or for the requested resource RequestDispatcher object is not implemented by the server.

Embedding the other resources in the response

include(request, response) method of RequestDispatcher object embedded the content with response of another resource while it is returned by the web component. Using this method you can write to the response body but, can't be set headers or call any method.

Passing control to the another web component

Transferring a control to the another web component is sometimes required in the case of where you want to perform some preliminary processing of a request by one web component and the response generation is perform by the another component.

javax.servlet.forward.[request-uri|context-path|servlet-path|path-info|query-string] method of RequestDispatcher is used to transfer the control from one web component to another. The requested URL locates the page that is responsible for replying to the user.

Getting Web Context

getServletContext() method is used to find out the web context, context is an object that implements the ServletContext interface, where the web components are executed. Methods of web context allows to access the following :

  • Initialization parameters
  • Associated resources of web context
  • Object-valued attributes
  • Logging capabilities

getAttribute() method is used by the filter to find out the counter object's.

Tutorials

  1. Java EE6 Tutorial
  2. Introduction of Web Application
  3. Introduction to JSF
  4. JSF 1.2 Simple Example
  5. JSF 2.0 Simple Example
  6. Introduction to Facelets
  7. Structure of Web Module
  8. Introduction To Java Servlet Technology
  9. Creating and Initializing a Servlet using Annotation
  10. service method in servlet
  11. Servlet Filter
  12. Calling another web resources
  13. Facelets Example
  14. Servlet Session
  15. Introduction To Enterprise Beans
  16. Types of Enterprise Beans
  17. Composite Components
  18. JSF Expression Language(EL)
  19. Servlet Finalization
  20. Internationalization and Localization of Web Applications in Java
  21. Download Eclipse Helios And Add The Tomcat7 For Java EE6
  22. Servlet Annotation Hello World Example in Eclipse
  23. @WebInitParam Annotation Servlet Example
  24. @WebListener Annotation Servlet Example
  25. @WebFilter Servlet Example
  26. @WebServlet Url Embedding Example
  27. @WebServlet RequestDispatcher Include Example
  28. @WebServlet RequestDispatcher Forward Example
  29. @WebServlet Login and Logout Example
  30. How to access Enterprise Beans
  31. Building Enterprise Bean Perspective to Allow Access
  32. Servlet setAttribute & getAttribute method example
  33. ServletResponse methods Servlet 3.0
  34. How to use web.xml in Servlet 3.0
  35. File Upload Servlet 3.0 Example
  36. Session Tracking Servlet Example
  37. Servlet 3 Async Example
  38. ServletContext Java EE 6
  39. setInitParameter() Method Example
  40. ServletRequest Java EE 6