servlet和jsp实现简单mvc转发

1 通过servlet获取参数

request.getParameter("paramName")

2 生成共享bean

Object value = new Object();
... some biz process to modify bean value
request.setAttribute("key", value);
request.getSession().setAttribute("key", value);
getServletContext().setAttribute("key", value);

3 分发请求到jsp

RequestDispatcher dispatcher = request.getRequestDispatcher("/WEB-INF/somePage.jsp");
dispatcher.forward(request, response);

4 jsp页面获取bean value，显示数据

为了不自动生成bean对象，jsp页面使用bean时，使用type 而不是class
<jsp:useBean id="key" type="somePackage.ValueObject" scope="request" />
<jsp:useBean id="key" type="somePackage.ValueObject" scope="session" />
<jsp:useBean id="key" type="somePackage.ValueObject" scope="application" />

<jsp:getProperty name="key" property="someProperty">

RequestDispatcher 与jsp动作对应关系
RequestDispatcher.include 对应<jsp:include ... />
RequestDispatcher.forward 对应<jsp:forward ... />