Java的MVC玩起来比.Net的有意思，因为每一步你都知道它是如何运作的，都由自己去实现。而在.Net的MVC中，你却不知道一个Controller是如何对应到View中的，因为MS给了你IDE上的操作方便，具体内部是如何做的映射，很难找到或不知道。
Java MVC的原理可有这样理解（网上说是这种）：JSP -> Servlet -> JSP
（个人认为最合适的是这样解释比较好）：Servlet -> JSP
即不需要让用户直接访问JSP。因为这是Resful风格哈。
上代码例子。
建一个Bean: User
package com.my.beans;
import java.lang.*;
public class User {
private String name;
private String password;
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public User() {}
}
建一个JSP：mvctest.jsp
<%@ page contentType="text/html;charset=utf-8" pageEncoding="utf-8"%> <html>
<header>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</header>
<body>
<form action="${pageContext.request.contextPath}/requestattr" method="POST">
User name: <input type="textbox" id="txtUserName" name="txtUserName" value="${param.txtUserName}" />
<input type="submit" value="Submit" /><br/>
<hr />
User name textbox value: ${param.txtUserName}<br/>
Bean user name value: ${userBean.name}<br/>
Bean password value: ${userBean.password}<br/>
Bean age value: ${userBean.age}<br/>
</form>
</body>
</html>
建一个Servlet: RequestAttr
package com.my; import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*; import com.my.beans.User; public class RequestAttr extends HttpServlet {
public RequestAttr() {} public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
req.getRequestDispatcher("/pages/mvctest.jsp").forward(req, resp);
} public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
PrintWriter out = resp.getWriter(); String strUserName = req.getParameter("txtUserName"); User user = new User();
user.setName(strUserName);
user.setPassword("123");
user.setAge(18); req.setAttribute("userBean", user);
req.getRequestDispatcher("/pages/mvctest.jsp").forward(req, resp);
}
}
web.xml修改：
<servlet>
<servlet-name>requestattr</servlet-name>
<servlet-class>com.my.RequestAttr</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>requestattr</servlet-name>
<url-pattern>/requestattr</url-pattern>
</servlet-mapping>
结果：
访问地址：http://localhost:8080/mytest/requestattr
一个MVC模型如来。性奋....