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eclipse 使用 javabean 出错,该如何处

发布时间: 2012-01-26 19:40:46 作者: rapoo

eclipse 使用 javabean 出错
我自己在做一个新闻发布系统,不太会用eclipse
错误信息为:
/WebRoot/index.jsp(3,0) The value for the useBean class attribute com.DBcon is invalid.
我的index页面为:
<%@ page contentType= "text/html; charset=gb2312 " language= "java " errorPage= " "%>
<%@ page import= "java.sql.* "%>
<jsp:useBean id= "db " class= "com.DBcon "/>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN ">
<html>
<head>

<title> 新闻发布 </title>

<meta http-equiv= "pragma " content= "no-cache ">
<meta http-equiv= "cache-control " content= "no-cache ">
<meta http-equiv= "expires " content= "0 ">
<meta http-equiv= "keywords " content= "keyword1,keyword2,keyword3 ">
<meta http-equiv= "description " content= "This is my page ">

</head>

<body>
<table align= "center " bgcolor= "#ffff80 ">
<tr>
<td> 新闻标题
</td>
<td> 发布人
</td>
<td> 发布时间
</td>
<td>
</td>
</tr>
<%
String sql= "select * from newspub ";
ResultSet rs=db.executeQuery(sql);
%>
<%
String title=rs.getString( "newsTitle ");
String content=rs.getString( "newsContent ");
%>
<tr>
<td>
<%=title%>
</td>
<td>
<%=content%>
</tr>
</table>
<%db.closeCon();%>
</body>
</html>
我的bean是:
package com;

import java.sql.*;

public class DBcon {
String Dbdriver = "com.microsoft.jdbc.sqlserver.SQLServerDriver ";

String strcon = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=newspub ";

Connection con = null;

Statement stmt = null;

ResultSet rs = null;

String user = "sa ";

String password = " ";

public DBcon() {
try {
Class.forName(Dbdriver);
} catch (ClassNotFoundException e) {


// TODO Auto-generated catch block
e.printStackTrace();
}

}

public ResultSet executeQuery(String strSQL) {
try {
con = DriverManager.getConnection(strcon, user, password);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {

Statement stmt = con.createStatement();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
rs = stmt.executeQuery(strSQL);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return rs;
}

public void executeUpdate(String strSQL) {
try {
con = DriverManager.getConnection(strcon, user, password);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_UPDATABLE);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
stmt.executeUpdate(strSQL);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

public void closeCon() {
if (con != null) {
try {
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
大哥们快快帮忙 啊!!!

[解决办法]
错误为com.DBcon类未找到
确保该类已经编译成功并放在classpath下
路径为com.DBcon
如果为编译成功查看构建路径,看看里面有没有问题
[解决办法]
<jsp:useBean id= "db " class= "com.DBcon "/>

当你敲 "com. "的时候看有没有智能提示DBCon, 如果没有那肯定找不到拉

如果找到了也出现上述错误的话,那就是RP问题了

[解决办法]
我也正在做这个论文

[解决办法]
在DBcon这个类里有db这个属性吗?

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