MVC全名是Model View Controller，是模型(model)－视图(view)－控制器(controller)的缩写，一种软件设计典范，用一种业务逻辑、数据、界面显示分离的方法组织代码
此框架模式是一个简单的解决个人所得税计算的业务逻辑
servlet
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
* Servlet implementation class TaxServlet
*/
public class TaxServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
String income = request.getParameter("income");
int n = Integer.parseInt(income);
// 控制器调用业务模型
// 模型 JavaBean
Tax tax = new Tax();
int result = tax.getResult(n);
// 结果存入作用域
HttpSession session = request.getSession();
session.setAttribute("ic", result);
// 跳转到 show.jsp
response.sendRedirect("show.jsp");
}
}JavaBean
实现对数据的处理：个人所得税的计算
public class Tax {
// 怎么计算个人所得税
public int getResult(int n) {
// 计算个人所得税
int x = n - 3500;
if (x <= 0) {
return 0;
}
if (x <= 1500) {
return (int) (x * 0.03f);
} else if (x <= 4500) {
return (int) (x * 0.1f - 105f);
} else if (x <= 9000) {
return (int) (x * 0.2f - 555f);
} else if (x <= 35000) {
return (int) (x * 0.25f - 1005f);
} else if (x <= 55000) {
return (int) (x * 0.3f - 2755f);
} else if (x <= 80000) {
return (int) (x * 0.35f - 5505f);
} else
return (int) (x * 0.45f - 13505f);
}
}
index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>个人所得税查询</title> </head> <body> <h1>计算个人所得税</h1> <form action="tax" method="post"> <input type="text" name="income"><input type="submit" value="提交"> </form> </body> </html>
show.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<span style="white-space:pre"> </span><!-- 内置对象session接收数据 -->
<span style="white-space:pre"> </span><%
<span style="white-space:pre"> </span>int n =( (Integer)session.getAttribute("ic")).intValue();
<span style="white-space:pre"> </span>%>
<span style="white-space:pre"> </span><h1><%=n %></h1>
</body>
</html>