用JavaBean来接受和传递参数的问题

实现JSP页面下的数据库查询和插入操作，
提示：
An error occurred at line: 18 in the jsp file: /insertData.jsp
Generated servlet error:
C:\Tomcat 5.0\work\Catalina\localhost\Myjsp\org\apache\jsp\insertData_jsp.java:89: cannot resolve symbol
symbol  : variable BookId
location: class org.apache.jsp.insertData_jsp
database.executeQuery("insert into t_book values('"+BookId+"','"+BookName+"','"+BookAuthor+"','"+BookPress+"','"+BookPrice+"','"+BookDate+"')");

共有六处错误，也就是六个参数传递的问题
showData.jsp代码如下：
<%@ page language="java" import="java.sql.*" contentType="text/html;charset=GBK" %>

<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=GBK">
<title>JavaBean访问数据库</title>
</head>
<body>
<p><b><div align=center>图书目录</b></p>

<jsp:useBean id="database" scope="session" class="hunan.JDBCBean"/>
<table border=1 cellpading=10>
<tr>
<th aligh=center>编号</th>
<th aligh=center>书名</th>
<th aligh=center>作者</th>
<th aligh=center>出版社</th>
<th aligh=center>价格</th>
<th aligh=center>出版日期</th>
</tr>
<%

ResultSet RS=database.executeQuery("select * from t_book");
while(RS.next())
{
out.print("<tr>");
out.print("<td>"+RS.getString("book_id")+"</td>");
out.print("<td>"+RS.getString("book_name")+"</td>");
out.print("<td>"+RS.getString("book_author")+"</td>");
out.print("<td>"+RS.getString("book_press")+"</td>");
out.print("<td>"+RS.getFloat("book_price")+"</td>");
out.print("<td>"+RS.getString("book_date").substring(0,10)+"</td>");
out.print("</tr>");
//注意数据类型
}

out.print("</table>");
RS.close();
%>
<br><br><br><hr>
<FORM action="insertData.jsp" method=post>
<p>编号:<INPUT type=text size=10 name="BookId">
   书名:<INPUT type=text size=10 name="BookName">
   作者:<INPUT type=text size=10 name="BookAuthor">
   出版社:<INPUT type=text size=10 name="BookPress">
   定价:<INPUT type=text size=10 name="BookPrice">
   出版日期(如02/29/2000):<INPUT type=text size=10 name="BookDate"></p>
<INPUT type="submit" value="送出" name=submit1>
<INPUT type="reset" value="清除" name=reset1>

</body>
</html>

insertData.jsp代码如下：
<%@ page language="java" import="java.sql.*" contentType="text/html;charset=GBK" %>

<html>
<head>
<title>插入信息</title>
<head>
<body>
<jsp:useBean id="bookdata" scope="session" class="hunan.BookData"/>

<jsp:setProperty name="bookdata" property="BookId"/>
<jsp:setProperty name="bookdata" property="BookName"/>
<jsp:setProperty name="bookdata" property="BookAuthor"/>
<jsp:setProperty name="bookdata" property="BookPress"/>
<jsp:setProperty name="bookdata" property="BookPrice"/>
<jsp:setProperty name="bookdata" property="BookDate"/>

<jsp:useBean id="database" scope="session" class="hunan.JDBCBean"/>
<%
database.executeQuery("insert into t_book values('"+BookId+"','"+BookName+"','"+BookAuthor+"','"+BookPress+"','"+BookPrice+"','"+BookDate+"')");
%>
<p><b><div align=center>数据已经成功插入</b></p>
<a href="showData.jsp" align=center>返回</a>
</body>
</html>

BookData.java代码如下：
package hunan;

public class BookData
{
private String BookId ="";
private String BookName ="";
private String BookAuthor ="";
private String BookPress ="";
private String BookPrice ="";
private String BookDate ="";

public BookData()
{
}

public void setBookId(String BookId)
{
this.BookId=BookId;
}

public void setBookName(String BookName)
{
this.BookName=BookName;
}

public void setBookAuthor(String BookAuthor)
{
this.BookAuthor=BookAuthor;
}

public void setBookPress(String BookPress)
{
this.BookPress=BookPress;
}

public void setBookPrice(String BookPrice)
{
this.BookPrice=BookPrice;
}

public void setBookDate(String BookDate)
{
this.BookDate=BookDate;
}

public String getBookId()
{
return this.BookId;
}

public String getBookName()
{
return this.BookName;
}

public String getBookAuthor()
{
return this.BookAuthor;
}

public String getBookPress()
{
return this.BookPress;
}

public String getBookPrice()
{
return this.BookPrice;
}

public String getBookDate()
{
return this.BookDate;
}
}

OS:我用内置对象request的getParameter()方法可以实现，但是我换用<jsp:setProperty>就不可以了，不知道为什么，showData.jsp没有问题，错误是在调用insertData.jsp时出现的，
而且，去掉insertData.jsp里的SQL语句，我用<jsp:getProperty>显示参数信息时，提示
Cannot find any information on property 'BookId' in a bean of type 'hunan.BookData'

请高手指点

8 个解决方案

#1

你把javabean中private String BookId ="";
private String BookName ="";
private String BookAuthor ="";
private String BookPress ="";
private String BookPrice ="";
private String BookDate ="";
和JSP页面中的Book全部改为小写b就可以了

#2

javabean中的属性命名是有规定的

把b全改为小写的吧。

#3

#4

应该把showData.jsp中的
while(RS.next())
{
out.print("<tr>");
out.print("<td>"+RS.getString("book_id")+"</td>");
out.print("<td>"+RS.getString("book_name")+"</td>");
out.print("<td>"+RS.getString("book_author")+"</td>");
out.print("<td>"+RS.getString("book_press")+"</td>");
out.print("<td>"+RS.getFloat("book_price")+"</td>");
out.print("<td>"+RS.getString("book_date").substring(0,10)+"</td>");
out.print("</tr>");
//注意数据类型
}
的book_id,book_name,...改为的‘b’改为大写，会快一点吧，因为你数据库里面都是大写的，你这样当然是错了！

#5

补充一点，我在数据库里的表项是book_id,book_name,这里的BookName等是我的临时变量，传递参数用的，我在用request.getParameter()时参数传递没有问题，也就是说showData.jsp没有错
我的同事给我的例子里，private String User为大写,这里采用大写主要考虑getBookName()方法的命名规律，(开头小写，以后每个单词都大写开头，:))

不过我会一试的，多谢

#6

public class TestBean
{
     private int userId;
     private String userName;

     public int getUserId()
     {
           return userId;
     }
     public void setUserId(int userId)
     {
           this.userId=userId;
     }
     public String getUserName()
     {
           return userName;
     }
     public void setUserName(String userName)
     {
           this.userName=userName;
     }
}
这样才符合JavaBean属性的命名规范,叫做getter和setter方法。

#7

多谢各位好意，规范的问题我会注意的，但是问题解决阿，那有什么用，期待达淫中.....

#8

问题解决：
String bookId=request.getParameter("bookId");
String bookName=request.getParameter("bookName");
bookName=new String(bookName.getBytes("ISO-8859-1"),"GBK");
String bookAuthor=request.getParameter("bookAuthor");
bookAuthor=new String(bookAuthor.getBytes("ISO-8859-1"),"GBK");
String bookPress=request.getParameter("bookPress");
bookPress=new String(bookPress.getBytes("ISO-8859-1"),"GBK");
String bookPrice=request.getParameter("bookPrice");
String bookDate=request.getParameter("bookDate");

添加如上代码，主要是SQL语句用到的变量要声明，以及中文编码解决。
还是感谢各位的支持，实际上不用以下代码
<jsp:useBean id="bookdata" scope="session" class="hunan.BookData"/>

<jsp:setProperty name="bookdata" property="bookId"/>
<jsp:setProperty name="bookdata" property="bookName"/>
<jsp:setProperty name="bookdata" property="bookAuthor"/>
<jsp:setProperty name="bookdata" property="bookPress"/>
<jsp:setProperty name="bookdata" property="bookPrice"/>
<jsp:setProperty name="bookdata" property="bookDate"/>
也可以实现，这就是我说的用request的getParameter()方法。

#1

#2

javabean中的属性命名是有规定的

把b全改为小写的吧。

#3

#4

#5

#6

#7

多谢各位好意，规范的问题我会注意的，但是问题解决阿，那有什么用，期待达淫中.....

秒客网

用JavaBean来接受和传递参数的问题

8 个解决方案

#1

#2

#3

#4

#5

#6

#7

#8

#1

#2

#3

#4

#5

#6

#7

#8

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