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XyzWs JSP FAQ:
What are implicit objects in JSP?

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XyzWs JSP FAQ: What are implicit objects in JSP?

What are implicit objects in JSP?

Implicit objects are a set of Java objects that the JSP Container makes available to developers in each page. These objects may be accessed as built-in variables via scripting elements and can also be accessed programmatically by JavaBeans and Servlets. You may already meet one of these objects already - the out object which allows you to send information to the output stream.

The implicit objects are created automatically for you within the service method. Furthermore, as summarized below, each object must adhere to a specific Java class or interface definition.

Object	Class or Interface	Description & Scope
`request`	`http.HttpServletRequest`	Data included with the HTTP Request. request scope.
`response`	`http.HttpServletResponse`	HTTP Response data, e.g. cookies. page scope.
`pageContext`	`jsp.pageContext`	Provides access to all the namespaces associated with a JSP page and access to several page attributes. page scope.
`session`	`http.HttpSession`	User specific session data. session scope.
`application`	`ServletContext`	Data shared by all application pages. application scope.
`out`	`jsp.JspWriter`	Output stream for page context. page scope.
`config`	`ServletConfig`	Servlet configuration information. page scope.
`page`	`jsp.HttpJspPage`	Page's servlet instance. page scope.

Note that the implicit variables are only available within the jspService method and thus are not available within any declarations. Thus for example the following code will cause a compile time error.

<%!
   public void amethod(){
        out.print("Hello");
   }   
%>