Session保存用户名
1.构造登录界面
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Session保存用户名</title> </head> <body> <form action="doS3" method= "post"> 用户名:<input type="text" name="name"/><br/> 密 码:<input type="password" name = "pwd"><br/> <input type="submit"> </form> </body> </html>
2.获取Session并将用户名保存到Session域对象中
package com.oaec.session;
import java.io.IOException;
import java.util.Date;
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 servletDemo3 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
resp.setContentType("text/html;charset=UTF-8");
// req.getAttribute(arg0)
String name = req.getParameter("name");
String pwd = req.getParameter("pwd");
if ("高圆圆".equals(name) && "123".equals(pwd)) {
// 将用户名保存在session中
// 1.获得session
HttpSession session = req.getSession();
// 2.将用户名保存在session中
session.setAttribute("uname", name);
resp.sendRedirect("doS4");
} else {
resp.sendRedirect("index.html");
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
3.从Session中取出数据 并对页面进行保护 没有登录通过URL访问 直接重定向到登录界面 即主页
package com.oaec.session;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
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 servletDemo4 extends HttpServlet{
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
resp.setContentType("text/html;charset=UTF-8");
//从session中取出数据
HttpSession session = req.getSession(false);
Object object = null;
if (session != null && (object = session.getAttribute("uname"))!=null) {
PrintWriter writer = resp.getWriter();
writer.write("登录成功<br>");
writer.write("欢迎你"+object);
}else {
//没有登录过 直接重定向到主页
resp.sendRedirect("index.html");
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}