J2EE 2nd Course Notes-Servlet

This lesson has some basic servlet knowledge!
1. Access the servlet locally (take the tomcat server as an example ):
Http: // locatlhost: 8080/servlet/name of your servlet
In this way, you can directly access this servlet!
2. When using jcreator for servlet programming, you need to import common/lib/servlet. jar under tomcat.
To call the servlet package
3. Test the program from the simplest Hello, World! To practice!
Code:
Import javax. servlet .*;
Import java. io .*;
Public class HelloServlet extends GenericServlet
{
// The service of the initial image class needs to be reloaded.
Public void service (ServletRequest request, ServletResponse response) throws IOExcetpion
{
PrintWriter out = response. getWriter ();
Out. println ("Hello, this is our world! ");
}
}
4. HttpServlet inherits GenericServlet, HttpServletRequest/HttpServletResponse inherits ServletRequest/ServletResponse
The getHeader method is used to obtain the header information.
Request. getHeader ("connection") to obtain the connection information
Request. getHeader ("User-Agent") to obtain User information

Example:
Import javax. servlet .*;
Import java. io .*;
Import javax. servlet. http. *; // you must import this package to use HttpServlet
Public class HelloServlet extends HttpServlet
{
// The service of the initial image class needs to be reloaded.
Public void service (HttpServletRequest request, HttpServletResponse response) throws IOExcetpion
{
PrintWriter out = response. getWriter ();
String s = request. getHeader ("Connection ");
String user = request. getHeader ("User-Agent ");
Out. println ("you connect to server is" + s );
Out. close ();
}
}
5. response. setContentType ("text/html; charset = gb2312 ")