值bean的应用
（1）若有如下图所示的两个JSP页面，在第一个的页面的表单中填写相应内容，提交后再显示用户的提交信息。使用JavaBean的方式实现上述效果，请写出相应的代码。
bean文件：Test2_1.java:
package com.lgqchinese.webJSPTest.shiyan4;
public class Test2_1 {
String bookName = "";
String bookNum = "";
double bookPrice = 0;
int bookPage = 0;
public void setBookName(String bookName) {
try {
byte[] b = bookName.getBytes("Iso-8859-1");
bookName = new String(b,"utf-8");
} catch (Exception e) {
}
this.bookName = bookName;
}
public void setBookNum(String bookNum) {
this.bookNum = bookNum;
}
public void setBookPrice(double bookPrice) {
this.bookPrice = bookPrice;
}
public void setBookPage(int bookPage) {
this.bookPage = bookPage;
}
public String getBookName() {
return bookName;
}
public String getBookNum() {
return bookNum;
}
public double getBookPrice() {
return bookPrice;
}
public int getBookPage() {
return bookPage;
}
}
from.jsp:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<jsp:useBean id="book" class="com.lgqchinese.webJSPTest.shiyan4.Test2_1" scope="request"/>
<html>
<head>
<title>Title</title>
</head>
<body>
<p>请输入书籍信息：</p>
<form action="gain.jsp" method="post">
书名：<input type="text" name="bookName">
书号：<input type="text" name="bookNum">
价钱：<input type="text" name="bookPrice">
页数：<input type="text" name="bookPage">
<input type="submit" value="提交">
<input type="reset" value="重置">
</form>
</body>
</html>
gain.jsp:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<jsp:useBean id="book" class="com.lgqchinese.webJSPTest.shiyan4.Test2_1" scope="request"/>
<html>
<head>
<title>Title</title>
</head>
<body>
<p>您输入的书籍信息如下：</p>
<jsp:setProperty name="book" property="*"/>
书名：<jsp:getProperty name="book" property="bookName"/>
<br>
书号：<jsp:getProperty name="book" property="bookNum"/>
<br>
价钱：<jsp:getProperty name="book" property="bookPrice"/>
<br>
页数：<jsp:getProperty name="book" property="bookPage"/> </body>
</html>
（2）编写一个可以实现四则运算的Bean，实现如下图所示的效果，请写出相应代码。
bean文件：Test_2:
package com.lgqchinese.webJSPTest.shiyan4;
public class Test2_2 {
double a = 0;
double b = 0;
double result = 0;
String oper = "+";
public void setA(double a) {
this.a = a;
}
public void setB(double b) {
this.b = b;
}
public void setOper(String o) {
oper = o.trim();
}
public double getA() {
return a;
}
public double getB() {
return b;
}
public double getResult() {
return result;
}
public String getOper() {
return oper;
}
public double method() {
if (oper.equals("+")){
result = a+b;
}
else if (oper.equals("-")){
result = a-b;
}
else if (oper.equals("*")){
result = a*b;
}
else if (oper.equals("/")&&b!=0){
result = a/b;
}
return result;
}
}
Test_2.jsp:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<jsp:useBean id="hello" class="com.lgqchinese.webJSPTest.shiyan4.Test2_2" scope="session"/>
<html>
<head>
<title>四则运算</title>
</head>
<body>
<jsp:setProperty name="hello" property="*"/>
<form action="" method="post" name="form">
<input type="text" name="a">
<select name="oper">
<option value="+">+
<option value="-">-
<option value="*">*
<option value="/">/
</select>
<input type="text" name="b">
<br>
<input type="submit" value="提交">
</form> <jsp:getProperty name="hello" property="a"/>
<jsp:getProperty name="hello" property="oper"/>
<jsp:getProperty name="hello" property="b"/>
<jsp:getProperty name="hello" property="result"/>
</body>
</html>