index.html
login.html
用户名:
密码:
package servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@WebServlet(“/TestServlet”)
public class TestServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//判断用户是否登录,从session中获取用户登录标识user,若不为null表示已经登录,否则未登录
request.setCharacterEncoding("UTF-8");
//获取session对象
HttpSession session=request.getSession();
String name=(String)session.getAttribute("user");
if(null!=name){
//已登录
System.out.println("已经登录,登录用户:"+name+",可以访问!");
}else {
//未登录
System.out.println("用户还未登录,禁止访问!");
}
}
}
package servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@WebServlet(“/LoginServlet”)
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//设置请求字符集
request.setCharacterEncoding("UTF-8");
String name=request.getParameter("loginName");
String pwd=request.getParameter("loginPwd");
//验证用户有效性
if("admin".equals(name)&&"123".equals(pwd)||"张三".equals(name)&&"666".equals(pwd)){
//登录成功
//在session中存储用户登录的标识
HttpSession session=request.getSession();
session.setAttribute("user", name);
//转发index页面
request.getRequestDispatcher("index.html").forward(request, response);
}else {
//登录失败
//转发login页面
request.getRequestDispatcher("login.html").forward(request, response);
}
}
}
package servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@WebServlet(“/LoginOutServlet”)
public class LoginOutServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//获取session对象,并将session销毁
HttpSession session=request.getSession();
session.invalidate();
System.out.println("已经注销用户!");
response.sendRedirect("index.html");
}
}