JSP implicit object Type Typical use by the scriptlet writer pageContext javax.servlet.jsp.PageContext Barely in use. This is more of a backbone object used by the servlet that was autogenerated from the servlet code. We will discuss the autogenerated servlet later in this chapter. request javax.servlet.http.HttpServletRequest Queries request information; for example, queries form parameters, inbound cookies, request headers, etc. response javax.servlet.http.HttpServletResponse Manipulates the response; for example, add cookies, redirect, etc. session javax.servlet.http.HttpSession Accesses the session state information associated with the request. For example, get/set session attributes or invalidate the session. config javax.servlet.ServletConfig Obtains configuration parameters for this page. application javax.servlet.ServletContext Obtains configuration parameters for this application and uses its utility method (for example, log()). out javax.servlet.jsp.JspWriter Writes data into the page and manipulates the output buffer used by JSP. page java.lang.Object Represents the Java this variable for the current page invocation. exception java.lang.Exception In error pages only (see more on error pages in the upcoming sections), represents the exception that triggered the error page.

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