Servlet and JSP knowledge Review (1) Servlet & amp; JSP technology Overview

ServletAnd jsp (preferred for SUN Enterprise Applications) knowledge Review (1) Servlet & jsp (preferred for SUN Enterprise Applications) technology Overview

 

1. ServletFunctions

· Read the explicit data (form data) sent by the client program)

· Read the implicit data (request header) sent by the client program)

· Generate corresponding results

· Send explicit data to the Client Program (HTML)

· Send implicit data to the Client Program (status code and Response Header)

 

2.Why do we need to build Web pages dynamically?

· The content on the web page is based on the data submitted by the user.

· The content on the web page is exported from frequently changing data

· The Web page uses information from databases or other server resources

 

3. servletAdvantages over traditional CGI technology

· High Efficiency

-Replace operating system processes with threads, with a single servlet copy

· Convenience

-Numerous high-level utilities

· Powerful functions

-Data sharing, connection sharing, and continuous Storage

· High portability

-Running on almost all operating systems and servers

· Low Cost

-You can choose from a large number of free or low-cost servers.

· Security

-If no shell program is designed, the transfer operator attack is eliminated.

There is no buffer overflow problem.

· Mainstream

 

4. assumerver Pages(Jsp (preferred for SUN Enterprise Applications)-servlet Function Extension

 

5.Implement a simple deployment Method

· Copy to a shortcut or symbolic link

-Create a shortcut for install_dir/webapps/ROOT/WEB-INF/classes.

-For servlets that do not use a package, copy the. class file to this shortcut.

-Copy the entire directory to the package's servlets

· This is the simplest method for beginners.

· Use the-d option of javac

-This method can be used to place the source file in a single location and automatically

The. class file is placed in another location.

· The IDE is responsible for deploying tools.

· Use ant or similar tools

-Ant is especially popular when custom Web applications are used.

 

6. WebApplication: preview

· Learning

-Use the default Web application (ROOT in tomcat (a useful JSP running platform)

-Use the default URL (http: //.../servlet/ServletName)

-A bit

· Simpler

· Tests can be performed without restarting the server or editing web. xml (standardization is getting closer and closer)

· Deployment

-Use the customized Web application (in tomcat (a very useful JSP running platform) as install_dir/webapps

A directory in which the structure is similar to ROOT)

-Register custom URLs in WEB-INF/web. xml (standardization is getting closer and closer)