A brief discussion on the instantiation interface corresponding to common objects in java web

1. request objects are instantiations of the javax. servlet. HttpServletRequest interface

2. The response object is an instantiation of the ES8en.servlet.HttpServletResponse interface

3. session objects are instantiations of the javax.servlet.HttpSession interface

4. The application object is an instantiation of the ES20en. servlet. ServletContext interface

These are common objects

5. pageContext object is javax. servlet. jsp. PageContext interface at the beginning of the instantiation, the object is rarely used in the programming of 1, but the label is used in the programming, the 1 point in the development of a label will detail later.

6. config object is the instantiation of javax.servlet.ServletConfig interface, server configuration, can get initialization parameters

7. out object is javax. servlet. jsp. JspWriter page output

8. The exception object is an instance of java.lang.Throwable and represents an exception that occurred on the JSP page and is only active in the error page

9. page is an instance of ES55en.lang.Object, representing one instance of Servlet represented from the page