1，理解mvc设计模式的核心思想，视图，模型，控制器。掌握mvc模式在jsp中的具体体现。
2，在mvc设计模式中，视图由jsp页面负责，模型由JavaBean负责，控制器由servlet负责。
3，模型(Model),一个或多个JavaBean对象，用于存数数据，JavaBean主要提供简单的setXXX()方法和getXXX()方法，在这些方法中不涉及对数据的具体处理细节。
4，视图(view),一个或者多个jsp页面，为模型提供数据展示，jsp页面主要使用HTML页面标记和JavaBean标记来显示数据
5，控制器(Controller):一个或者多个Servlet对象，根据视图提交的要求进行数据处理操作，并将有关结果存储到JavaBean当中，然后Servlet使用重定向方式请求视图中的某个jsp页面的更新显示，即让该jsp页面使用通过JavaBean标记显示控制器存储在JavaBean中的数据
下面是我设计的web应用，有两个jsp页面，inputNumber.jsp和showResult.jsp,一个javaBean和一个Servlet。jsp页面的inputNumber.jsp挺一个表单。，用户可以通过表单输入两个数和四则运算符号。提交给Servlet控制器，javaBean负责存储运算数，运算符号，运算结果。servlet负责四则运算，并将结果存储在javabean当中，并负责请求jsp页面showResult.jsp页面，显示javaBean中的数据。
主要用到的知识，转发。mvc设计思想。
step1，
inputNumber.jsp
[html]
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
</head>
<body>
<form action="operationservlet" method="post">
请输入数字1 <input type="text" name="number1"> 选择运算符 <input
type="radio" name="operation" value="+" checked /> <input
type="radio" name="operation" value="-"> <input type="radio"
name="operation" value="*"> <input type="radio"
name="operation" value="/"> 请输入数字2 <input type="text"
name="number2"> <input type="submit" value="提交">
</form>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
</head>
<body>
<form action="operationservlet" method="post">
请输入数字1 <input type="text" name="number1"> 选择运算符 <input
type="radio" name="operation" value="+" checked /> <input
type="radio" name="operation" value="-"> <input type="radio"
name="operation" value="*"> <input type="radio"
name="operation" value="/"> 请输入数字2 <input type="text"
name="number2"> <input type="submit" value="提交">
</form>
</body>
</html>
step2
javaBean文件
[java]
public class Operation {
private int number1;
private String operation;
private int number2;
private int result;
public int getResult() {
return result;
}
public void setResult(int result) {
this.result = result;
}
public int getNumber1() {
return number1;
}
public void setNumber1(int number1) {
this.number1 = number1;
}
public String getOperation() {
return operation;
}
public void setOperation(String operation) {
this.operation = operation;
}
public int getNumber2() {
return number2;
}
public void setNumber2(int number2) {
this.number2 = number2;
}
}
public class Operation {
private int number1;
private String operation;
private int number2;
private int result;
public int getResult() {
return result;
}
public void setResult(int result) {
this.result = result;
}
public int getNumber1() {
return number1;
}
public void setNumber1(int number1) {
this.number1 = number1;
}
public String getOperation() {
return operation;
}
public void setOperation(String operation) {
this.operation = operation;
}
public int getNumber2() {
return number2;
}
public void setNumber2(int number2) {
this.number2 = number2;
}
}
step4
servlet控制器
[java]
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import bean.Operation;
public class operationServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Operation oper=new Operation();
request.setAttribute("operation", oper);
String number11=request.getParameter("number1");
String operation=request.getParameter("operation");
System.out.println("我爱你"+operation);
String number22=request.getParameter("number2");
int number1=Integer.parseInt(number11);
int number2=Integer.parseInt(number22);
oper.setNumber1(number1);
oper.setNumber2(number2);
oper.setOperation(operation);
if(operation.equals("+")){
oper.setResult(number2+number1);
}
else if(operation.equals("-")){
oper.setResult(number1-number2);
}
else if(operation.equals("*")){
oper.setResult(number1*number2);
}
else{
oper.setResult(number1/number2);
}
// response.sendRedirect("showResult.jsp");
RequestDispatcher dispatcher=request.getRequestDispatcher("showResult.jsp");
dispatcher.forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import bean.Operation;
public class operationServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Operation oper=new Operation();
request.setAttribute("operation", oper);
String number11=request.getParameter("number1");
String operation=request.getParameter("operation");
System.out.println("我爱你"+operation);
String number22=request.getParameter("number2");
int number1=Integer.parseInt(number11);
int number2=Integer.parseInt(number22);
oper.setNumber1(number1);
oper.setNumber2(number2);
oper.setOperation(operation);
if(operation.equals("+")){
oper.setResult(number2+number1);
}
else if(operation.equals("-")){
oper.setResult(number1-number2);
}
else if(operation.equals("*")){
oper.setResult(number1*number2);
}
else{
oper.setResult(number1/number2);
}
// response.sendRedirect("showResult.jsp");
RequestDispatcher dispatcher=request.getRequestDispatcher("showResult.jsp");
dispatcher.forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}
step4，显示结果
[html]
<%@ page language="java" import="java.util.*,bean.Operation" pageEncoding="utf-8"%>
<html>
<head>
</head>
<body>
<%
Operation oper=(Operation)request.getAttribute("operation");
System.out.println(oper);
out.println(oper.getResult());
%>
</body>
</html>
<%@ page language="java" import="java.util.*,bean.Operation" pageEncoding="utf-8"%>
<html>
<head>
</head>
<body>
<%
Operation oper=(Operation)request.getAttribute("operation");
System.out.println(oper);
out.println(oper.getResult());
%>
</body>
</html>
