Ajax实战用户管理系统-完成数据初始化

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程序员老陆 2020-07-14 12:00:30 博主文章分类：front ©著作权

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1 通过 Ajax 完成页面数据初始化

<script>
        $(function () {
            //获取页面初始化数据
            getData();
            //添加按钮绑定点击事件
            $("#add").click(function(){
                addOrUpdateUser("addUser");
            });
            //更新按钮绑定点击事件
            $("#update").click(function(){
                addOrUpdateUser("updateUser");
            });
        });
        //获取页面初始化数据
        function getData(){
            $.getJSON("user.do",{flag:"getData"},function (result) {
                init(result);
            });
        }
        //遍历数据生成数据
        function init(obj){
            var str ="";
            $.each(obj,function(){
                str+= "<tr align='center'><td id='"+this.userid+"'>"+this.userid +"</td><td>"+this.username+"</td><td>"+this.usersex+"</td><td>"+this.userbirth+"</td><td><a href='#' onclick='preUpdateUser("+this.userid+")'>选择更新</a>&nbsp;&nbsp;&nbsp;<a href='#' onclick='deleteUser("+this.userid+")'>删除</a></td></tr>"
            });
            $("#tBody").prepend(str);
        }
   </script>

2 创建 Servlet 处理页面数据初始化请求

/**
 * 用户管理Servlet
 */
@WebServlet("/user.do")
public class UserServlet extends HttpServlet {
    //生成模拟数据初始化
    @Override
    public void init() throws ServletException {
        User user = new User();
        user.setUserid(1);
        user.setUsername("Oldlu");
        user.setUsersex("male");
        user.setUserbirth(new Date());
        User user2 = new User();
        user2.setUserid(2);
        user2.setUsername("Kevin");
        user2.setUsersex("male");
        user2.setUserbirth(new Date());
        List<User> list = new ArrayList<>();
        list.add(user);
        list.add(user2);
        ServletContext servletContext = this.getServletContext();
        servletContext.setAttribute("list",list);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            String flag = req.getParameter("flag");
            if("getData".equals(flag)){
                this.getData(req,resp);
            }else if("addUser".equals(flag)){
                this.addUser(req,resp);
            }else if("updateUser".equals(flag)){
                this.updateUser(req,resp);
            }else{
                this.deleteUser(req,resp);
            }
    }

    //获取页面初始化数据
    private void getData(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        List<User> list = (List<User>) this.getServletContext().getAttribute("list");
        String s = JsonUtils.objectToJson(list);
        resp.setContentType("application/json");
        PrintWriter pw = resp.getWriter();
        pw.print(s);
        pw.flush();
        pw.close();
    }
}