Smart-MVC

发表于

SmartMVC 是Spring MVC 框架克隆版。
设计目标： 将复杂的Web编程封装起来，使开发更加快速便捷。

控制器与业务功能拆分：

  1. 创建前端控制器：

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    public class DispatcherServlet extends HttpServlet {
        private static final long serialVersionUID = 1L;

        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            //检查request\response引用的对象类型
            Class cls1 = request.getClass();
            Class cls2 = response.getClass();
            System.out.println(cls1);
            System.out.println(cls2);

            //调用业务方法，根据业务方法的返回值转发到JSP
            BizController controller=new BizController();
            //执行业务方法，得到转发的目标页面名称
            String target = controller.execute(request);
            //将目标页面名称前后增加 JSP文件的位置和后缀
            String path = "/WEB-INF/jsp/"+target+".jsp";
            request.getRequestDispatcher(path)
            .forward(request, response); 
        }

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

  2. 配置 web.xml，使前端控制器可以处理任何 * .do 请求

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    <servlet>
        <description></description>
        <display-name>DispatcherServlet</display-name>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>mvc.DispatcherServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>

  3. 编写控制器类，封装业务功能

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    /**
     * 控制器类， 用于封装业务功能， 
     */
    public class BizController {
        /**
         * 第一个业务功能，Hello World! 
         * @return 目标页面名称
         */
        public String execute(HttpServletRequest request) {
            System.out.println("Hello World!");
            request.setAttribute("msg", "Hello"); 
            return "hello"; 
        }
    }

  4. 编写 /WEB-INF/jsp/hello.jsp

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    <%@ page 
      language="java" 
      contentType="text/html; charset=UTF-8"
      pageEncoding="UTF-8"%>
    <!DOCTYPE html>
    <html>
    <head>
    <meta charset="UTF-8"> 
    <title>Hello</title>
    </head>
    <body>
      <h1>Hello World！</h1>
      <p>${msg}</p>
    </body>
    </html>

  5. 测试：

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    http://localhost:8080/Servlet12/test.do