各位帮忙看看啊,我有几个这种程序都是这一种错误,郁闷几天啦!!!jsp程序如下:
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<jsp:useBean id="DBconn1" scope="page" class="NewsVersion.MySQLconn"/>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>无标题文档</title>
</head><body>
<%
String String_SQL="select * from book";
ResultSet rs=DBconn1.executeQuery(String_SQL);
String usercontent;
if(rs.next())
{
usercontent=rs.getString("about");
}
out.print(usercontent);
%>
</body>
</html>Bean程序如下:package NewsVersion;
import java.sql.*;
public class MySQLconn {
String DBDriver = "org.gjt.mm.mysql.Driver";
String ConnStr = "jdbc:mysql://localhost:3306/bookstore?user=root&password=200000&useUnicode=true&characterEncoding=8859_1";
Connection conn = null;
ResultSet rs = null;
public MySQLconn(){
try{
Class.forName(DBDriver);
//加载数据库驱动程序
}
catch(java.lang.ClassNotFoundException e) {
System.err.println("MySQLconn(): "+e.getMessage());
}
}
public ResultSet executeQuery(String sql){
//以记录集为返回值的函数
rs = null;
try {
conn = DriverManager.getConnection(ConnStr);
//与DBMS建立链接
Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs = stmt.executeQuery(sql);
}
catch(SQLException ex) {
System.err.println("aq.executeQuery:"+ex.getMessage());
}
return rs;
}
}错误提示:HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: /dbBean4/1.jsp(3,0) The value for the useBean class attribute NewsVersion.MySQLconn is invalid. org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264) javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause org.apache.jasper.JasperException: /dbBean4/1.jsp(3,0) The value for the useBean class attribute NewsVersion.MySQLconn is invalid. org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:39) org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:405) org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java……
这只是一个代表,每一个Bean调mysql的程序都这样,网上拷的也是如此,高手指点下吧
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<jsp:useBean id="DBconn1" scope="page" class="NewsVersion.MySQLconn"/>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>无标题文档</title>
</head><body>
<%
String String_SQL="select * from book";
ResultSet rs=DBconn1.executeQuery(String_SQL);
String usercontent;
if(rs.next())
{
usercontent=rs.getString("about");
}
out.print(usercontent);
%>
</body>
</html>Bean程序如下:package NewsVersion;
import java.sql.*;
public class MySQLconn {
String DBDriver = "org.gjt.mm.mysql.Driver";
String ConnStr = "jdbc:mysql://localhost:3306/bookstore?user=root&password=200000&useUnicode=true&characterEncoding=8859_1";
Connection conn = null;
ResultSet rs = null;
public MySQLconn(){
try{
Class.forName(DBDriver);
//加载数据库驱动程序
}
catch(java.lang.ClassNotFoundException e) {
System.err.println("MySQLconn(): "+e.getMessage());
}
}
public ResultSet executeQuery(String sql){
//以记录集为返回值的函数
rs = null;
try {
conn = DriverManager.getConnection(ConnStr);
//与DBMS建立链接
Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs = stmt.executeQuery(sql);
}
catch(SQLException ex) {
System.err.println("aq.executeQuery:"+ex.getMessage());
}
return rs;
}
}错误提示:HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: /dbBean4/1.jsp(3,0) The value for the useBean class attribute NewsVersion.MySQLconn is invalid. org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264) javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause org.apache.jasper.JasperException: /dbBean4/1.jsp(3,0) The value for the useBean class attribute NewsVersion.MySQLconn is invalid. org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:39) org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:405) org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java……
这只是一个代表,每一个Bean调mysql的程序都这样,网上拷的也是如此,高手指点下吧
换个驱动com.mysql.jdbc.Driver试下
Class.forName("com.mysql.jdbc.Driver");
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
String dbUrl="jdbc:mysql://localhost:3306/bookstore?useUnicode=true&characterEncoding=gb2312";
String dbUser="root";
String dbPwd="200000";
con=java.sql.DriverManager.getConnection(dbUrl,dbUser,dbPwd);