Servlet小的登陆功能的实现

来源：互联网发布：淘宝上传虚假授权书编辑：程序博客网时间：2024/05/16 05:59

1.首先写一个servlet返回登陆界面

public class Login extends HttpServlet{

   @Override
   protected void doGet(HttpServletRequest req, HttpServletResponse resp)
           throws ServletException, IOException {
       // TODO Auto-generated method stub
       resp.setContentType("text/html;charset=utf-8");
       PrintWriter pw = resp.getWriter();
       //中文乱码

       pw.println("<html>");
       pw.println("<body>");
       pw.println("<h1>登陆界面</h1>");
       pw.println("<form action=val method=post>");
       pw.println("用户名:<input type=text name=username> <br>");
       pw.println("密码:<input type=password name=passwd> <br>");
       pw.println("<input type=submit value=login><br>");
       pw.println("</form>");
       pw.println("</body>");
       pw.println("</html>");
   }

   @Override
   protected void doPost(HttpServletRequest req, HttpServletResponse resp)
           throws ServletException, IOException {
       // TODO Auto-generated method stub
       this.doGet(req, resp);
   }
}

2.其次在写一个servlet val处理登陆时的逻辑代码

public class LoginValidate extends HttpServlet{
   @Override
   protected void doGet(HttpServletRequest req, HttpServletResponse resp)
           throws ServletException, IOException {
       // TODO Auto-generated method stub
       //接收用户名和密码
       String u = req.getParameter("username");
       String p = req.getParameter("passwd");
       System.out.println(u+p);
       if(u.equals("gac")&&p.equals("123")){
           //合法
           resp.sendRedirect("wel");
       }else{
           //不合法
           System.out.println("not login suceess");
           resp.sendRedirect("login");//需要跳转的Servlet的url
       }
   }

   @Override
   protected void doPost(HttpServletRequest req, HttpServletResponse resp)
           throws ServletException, IOException {
       // TODO Auto-generated method stub
       this.doGet(req, resp);
   }

}

//最后为登陆成功跳转界面的servlet

public class WelCome extends HttpServlet{
   @Override
   protected void doGet(HttpServletRequest req, HttpServletResponse resp)
           throws ServletException, IOException {
       // TODO Auto-generated method stub
       PrintWriter pw = resp.getWriter();
       pw.println("Login Success");
   }

   @Override
   protected void doPost(HttpServletRequest req, HttpServletResponse resp)
           throws ServletException, IOException {
       // TODO Auto-generated method stub
       this.doGet(req, resp);
   }
}

部署文件web.xml配置

<servlet>
       <servlet-name>hello</servlet-name>
       
       <servlet-class>com.gac.test.Login</servlet-class>

       <load-on-startup>1</load-on-startup>
   </servlet>

   <servlet-mapping>
       <servlet-name>hello</servlet-name>
       
       <url-pattern>/login</url-pattern>
   </servlet-mapping>

   <servlet>
       <servlet-name>val</servlet-name>
       
       <servlet-class>com.gac.test.LoginValidate</servlet-class>

       <load-on-startup>1</load-on-startup>
   </servlet>

   <servlet-mapping>
       <servlet-name>val</servlet-name>
       
       <url-pattern>/val</url-pattern>
   </servlet-mapping>


   <servlet>
       <servlet-name>wel</servlet-name>
       
       <servlet-class>com.gac.test.WelCome</servlet-class>


   </servlet>

   <servlet-mapping>
       <servlet-name>wel</servlet-name>
       
       <url-pattern>/wel</url-pattern>
   </servlet-mapping>

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