JavaWeb核心知识点实战简单学生管理系统

这个版本是没有数据库的,存储于文本需要用到IO流,用到的知识有:登录的form表单以及获取表单数据,bootstrap简单修饰界面,servlet相关知识点如:四大作用域对象存储数据进行交互,session销毁登录状态,cookie实现最后一次访问时间的记录,请求转发(请求域一次请求中有效)用作回显数据,重定向跳转页面,filter乱码过滤器和权限过滤器等等...

流程图:

纯手工作图感觉不错,这才像样么.以后多画.提示思路而且有方向.

Servlet是用来处理逻辑的,jsp是显示页面的,虽然说jsp也是Servlet但是显示页面还是jsp更专业,因为jsp就是个长得像html的Servlet.暂时没有使用mvc模式就contraller做逻辑吧.

登录效果:

登录成功:

查看学生:

记事本作为假数据库存储

登录失败:

登录失败回显数据至登录页面

filter乱码过滤器:

package com.zgl.web.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

@WebFilter("/*")
public class CharacterEncodingFilter implements Filter {
    public void destroy() {
    }

    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");
        chain.doFilter(req, resp);
    }

    public void init(FilterConfig config) throws ServletException {

    }

}

filter权限过滤器:

package com.zgl.web.filter;



import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebFilter("/*")
public class LoginFilter implements Filter {
    public void destroy() {
    }

    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
      HttpServletRequest request=(HttpServletRequest) req;
        HttpServletResponse response=(HttpServletResponse) resp;
        String url = request.getRequestURL().toString().toLowerCase();
        System.out.println(url);
        if (url.contains("css")||url.contains("fonts")||url.contains("login")){
            chain.doFilter(request,response);

        }else if (request.getSession().getAttribute("name")!=null){
            chain.doFilter(request,response);
        }else {
            response.sendRedirect(request.getContextPath()+"/login.jsp");
        }

        }




  /*      chain.doFilter(req, resp);*/


    public void init(FilterConfig config) throws ServletException {

    }

}

笔者时间有限还没写完陆续更新...