关于JSP的一点疑问小结

用户名:

密码:

<%@ page language="java" import = java.util.* pageEncoding="ISO-8859-1"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>


<%! boolean isnotlogin = false;%>
<%
String username = request.getParameter("username");
String password = request.getParameter("password");
if(username == null || password == null)
{
response.sendRedirect("error.jsp");
return;
}
%>




<%
isnotlogin = person.judge();
if(!isnotlogin)
{
response.sendRedirect("error.jsp");
return;
}
else
{
session.setAttribute("username", request.getParameter("username"));
%>



<%
}
%>

package mypack;
public class register {
private String username = "";
private String pwd = "";
public void setUserName(String nm)
{
this.username = nm;
}
public String getUserName()
{
return this.username;
}
public void setPwd(String pd)
{
this.pwd = pd;
}
public String getPwd()
{
return this.pwd;
}
public boolean judge()
{
boolean temp = false;
if(username.equals("teacher") && pwd.equals("teacher"))
{
temp = true;
}
return temp;
}
}
sbmt.java(Servlet)部分:
package mypack;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class sbmt extends HttpServlet {
private static final long serialVersiOnUID= 1L;
public sbmt() {
super();
}
public void destroy() {
super.destroy();
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("");
out.println("");
out.println(" ");
out.println(" ");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the GET method");
out.println(" ");
out.println("");
out.flush();
out.close();
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
HttpSession session = request.getSession(false);
if(session == null)
{
response.sendRedirect("error.jsp");
return;
}
String usernameOne= (String)session.getAttribute("username");
String usernametwo = request.getParameter("username");
if(!usernameone.equals(usernametwo))
{
response.sendRedirect("error.jsp");
return;
}
response.setContentType("text/html;charset = GBK");
request.setAttribute("username", usernametwo);
if(usernametwo.equals("teacher"))
{
response.sendRedirect("teacher.jsp");
return;
}
else
{
response.sendRedirect("error.jsp");
return;
}
}
}
}