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:
1 package com.lgqchinese.webJSPTest.shiyan4; 2 3 public class Test2_1 { 4 String bookName = ""; 5 String bookNum = ""; 6 double bookPrice = 0; 7 int bookPage = 0; 8 9 public void setBookName(String bookName) { 10 try { 11 byte[] b = bookName.getBytes("Iso-8859-1"); 12 bookName = new String(b,"utf-8"); 13 } catch (Exception e) { 14 15 } 16 this.bookName = bookName; 17 } 18 19 public void setBookNum(String bookNum) { 20 this.bookNum = bookNum; 21 } 22 23 public void setBookPrice(double bookPrice) { 24 this.bookPrice = bookPrice; 25 } 26 27 public void setBookPage(int bookPage) { 28 this.bookPage = bookPage; 29 } 30 31 public String getBookName() { 32 return bookName; 33 } 34 35 public String getBookNum() { 36 return bookNum; 37 } 38 39 public double getBookPrice() { 40 return bookPrice; 41 } 42 43 public int getBookPage() { 44 return bookPage; 45 } 46 }
from.jsp:
1 <%@ page contentType="text/html;charset=UTF-8" language="java" %> 2 <jsp:useBean id="book" class="com.lgqchinese.webJSPTest.shiyan4.Test2_1" scope="request"/> 3 <html> 4 <head> 5 <title>Title</title> 6 </head> 7 <body> 8 <p>请输入书籍信息：</p> 9 <form action="gain.jsp" method="post"> 10 书名：<input type="text" name="bookName"> 11 书号：<input type="text" name="bookNum"> 12 价钱：<input type="text" name="bookPrice"> 13 页数：<input type="text" name="bookPage"> 14 <input type="submit" value="提交"> 15 <input type="reset" value="重置"> 16 </form> 17 </body> 18 </html>
gain.jsp:
1 <%@ page contentType="text/html;charset=UTF-8" language="java" %> 2 <jsp:useBean id="book" class="com.lgqchinese.webJSPTest.shiyan4.Test2_1" scope="request"/> 3 <html> 4 <head> 5 <title>Title</title> 6 </head> 7 <body> 8 <p>您输入的书籍信息如下：</p> 9 <jsp:setProperty name="book" property="*"/> 10 书名：<jsp:getProperty name="book" property="bookName"/> 11 <br> 12 书号：<jsp:getProperty name="book" property="bookNum"/> 13 <br> 14 价钱：<jsp:getProperty name="book" property="bookPrice"/> 15 <br> 16 页数：<jsp:getProperty name="book" property="bookPage"/> 17 18 </body> 19 </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:
1 package com.lgqchinese.webJSPTest.shiyan4; 2 3 public class Test2_2 { 4 double a = 0; 5 double b = 0; 6 double result = 0; 7 String oper = "+"; 8 9 public void setA(double a) { 10 this.a = a; 11 } 12 13 public void setB(double b) { 14 this.b = b; 15 } 16 17 public void setOper(String o) { 18 oper = o.trim(); 19 } 20 21 public double getA() { 22 return a; 23 } 24 25 public double getB() { 26 return b; 27 } 28 29 public double getResult() { 30 return result; 31 } 32 33 public String getOper() { 34 return oper; 35 } 36 37 public double method() { 38 if (oper.equals("+")){ 39 result = a+b; 40 } 41 else if (oper.equals("-")){ 42 result = a-b; 43 } 44 else if (oper.equals("*")){ 45 result = a*b; 46 } 47 else if (oper.equals("/")&&b!=0){ 48 result = a/b; 49 } 50 return result; 51 } 52 }
Test_2.jsp:
1 <%@ page contentType="text/html;charset=UTF-8" language="java" %> 2 <jsp:useBean id="hello" class="com.lgqchinese.webJSPTest.shiyan4.Test2_2" scope="session"/> 3 <html> 4 <head> 5 <title>四则运算</title> 6 </head> 7 <body> 8 <jsp:setProperty name="hello" property="*"/> 9 <form action="" method="post" name="form"> 10 <input type="text" name="a"> 11 <select name="oper"> 12 <option value="+">+ 13 <option value="-">- 14 <option value="*">* 15 <option value="/">/ 16 </select> 17 <input type="text" name="b"> 18 <br> 19 <input type="submit" value="提交"> 20 </form> 21 22 <jsp:getProperty name="hello" property="a"/> 23 <jsp:getProperty name="hello" property="oper"/> 24 <jsp:getProperty name="hello" property="b"/> 25 <jsp:getProperty name="hello" property="result"/> 26 </body> 27 </html>