Day

01-thymeleaf分支渲染(了解)02-thymeleaf列表渲染(掌握)03-lombok插件引入(掌握)04-ModelbaseServlet类(掌握)05-ModelbaseServlet执行流程(掌握)

概述

使用th:swtich、th:case指令进行分支渲染

代码实现

@WebServlet("/demo01")
public class Demo01Servlet extends ViewbaseServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String role = "super";
        request.setAttribute("role", role);
        processTemplate("demo01", request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }
}

    
    






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    管理员
    用户

概述

使用th:each进行列表渲染，类似于vue中的v-for

代码实现

@WebServlet("/demo02")
public class Demo02Servlet extends ViewbaseServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        List userList = new ArrayList<>();
        userList.add(new User(1, "张三", "root"));
        userList.add(new User(2, "李四", "admin"));
        userList.add(new User(3, "王五", "12345"));
        request.setAttribute("userList", userList);
        processTemplate("demo02", request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }
}

    
    





    

        
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姓名
        
密码
    

开发步骤

①idea安装lombok插件②idea允许注解运行③重启idea④引入lombok的jar包⑤使用lombok的注解

①idea安装lombok插件

②idea允许注解运行

③重启idea

④引入lombok的jar包

⑤使用lombok的注解

@NoArgsConstructor
@AllArgsConstructor
@Data
public class User {

    private Integer userId;
    private String userName;
    private String userPwd;


}

jar包下载网址

Maven Repository: org.projectlombok » lombok » 1.18.22 (mvnrepository.com) 04-ModelbaseServlet类(掌握)

概述

原来，一个功能就是一个Servlet，这样就导致Servlet太多了，难以维护。

代码实现

    
    



添加用户
删除用户
修改用户
查询用户



---------------------------------


添加用户
删除用户
修改用户
查询用户

public class ModelbaseServlet extends ViewbaseServlet {


    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //①获取method
        String methodName = req.getParameter("method");
        try {
            //②获取method对象
            Method method = this.getClass().getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
            //③反射动态执行
            method.invoke(this, req, resp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

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

@WebServlet("/user")
public class UserServlet extends ModelbaseServlet {

    public void addUser(HttpServletRequest request, HttpServletResponse response){
        System.out.println("UserServlet addUser");
        System.out.println("request = " + request);
        System.out.println("response = " + response);
    }


    public void deleteUser(HttpServletRequest request, HttpServletResponse response){
        System.out.println("UserServlet deleteUser");
    }

    public void updateUser(HttpServletRequest request, HttpServletResponse response){
        System.out.println("UserServlet updateUser");
    }

    public void selectUser(HttpServletRequest request, HttpServletResponse response){
        System.out.println("UserServlet selectUser");
    }


}

执行流程