severlet 简单交互

severlet 基本交互原理图

1.登录页面提交
<form action="login" method="get">
        姓名：<input type="text" name="userName"><br>
        密码：<input type="password" name="pwd"><br>
        <input type="submit" value="登录">
    </form>
2.web.xml接收，映射severlet文件
<servlet>
    <servlet-name>loginSeverlet</servlet-name>
    <servlet-class>com.severlet.loginSeverlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>loginSeverlet</servlet-name>
    <url-pattern>/login</url-pattern>
  </servlet-mapping>    
  <welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
  </welcome-file-list>
3.severlet处理数据
public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
        
    }

    
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String name=request.getParameter("userName");
        String pwd=request.getParameter("pwd");
        /*System.out.println(name);*/
        String username="hj";
        String password="123";
        if(username.equals(name) & password.equals(pwd)){
            response.getWriter().print("YES!!!");
        }else{
            response.getWriter().print("NO!!!");
        }
    }