Detailed description of JSP basic knowledge points

1jsp is a Java Server Pages and Servlet, both of which are developed by Sun and can be used to develop dynamic web pages. JSP is generally placed under the web template directory. JSP inherits servlet.

2. Why can I directly use some requests? Because it inherits Servlet and the request variables have long been defined.

3 Although JSP and servlet can basically interact with each other, JSP is used for view processing by default, and servlet is responsible for processing Logical Data.

4. jsp Syntax:

JSP template element, <%! %> This is equivalent to defining this broken code outside the servlet (JSP inherits the servlet), so the content in the lifecycle has a global

5. jsp can be used to import packets separately.

6. The session can be switched in JSP, but can be manually created after it is turned off.

7. If JSP has an exception, you can use errorpage to jump to the friendly page. Generally, the configuration in XML is better.

8. garbled characters occur because the local code table is different from the server code table.

9jsp: Page instruction, include instruction, taglib instruction

10. All command formats: <% @ command %>

11. inlcude allows two JSP files to appear in one JSP file. The include command can translate a servlet, which is a static inclusion. Do not use dynamic inclusion. Static inclusion is generally used in development. High efficiency.

12.9 large built-in objects:

Request Response session application page exception out pagecontext config

Among them, JSP excludes out and pagecontext.

13. One more JSP buffer is available for out. Therefore, out. Write () is slower than response. getwrite. Write ().

14. pagecontext is the most important of JSP. It encapsulates eight other large objects, its own domains to store data, and the operations frequently involved in Web development.

Pagecontext is generally used in the custom tag technology, because a good JSP page does not show a JSP code.

The findattribute key of pagecontext. It automatically searches for attributes and expands the scope step by step.

15. Common JSP labels: <JSP: Include> <JSP: forword> <JSP: param>