Why JavaBean load jdbc driver failed?

Thread view:

Allen - 02 Aug 2006 07:42 GMT

In jsp, forName("sun.jdbc.odbc.JdbcOdbcDriver") run successfully. When
used in JavaBean,
forName will fail. While run JavaBean class directly, it works. Why?

The following is the code.

package com;

import java.io.*;
import java.util.*;
import java.sql.*;

public class Publisher {

    String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
    Connection conn = null;
    ResultSet rs = null;

    public Publisher() {
    }

    public boolean open(String url, String user, String passwd) {
        try {
            Class.forName(driver).newInstance();
            conn = DriverManager.getConnection(url, user, passwd);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
            return false;
        } catch (SQLException e) {
            e.printStackTrace();
            return false;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }

        return true;
    }

    public ResultSet executeQuery(String sql) {

        if (conn == null) {
            return null;
        }

        rs = null;
        try {
            Statement stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
        }
        catch (SQLException e) {
            e.printStackTrace();
        }
        return rs;
    }

    public void close() {

        try {
            rs.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {

        Publisher pb = new Publisher();
        pb.open("jdbc:odbc:Publisher", "user", "user");
        ResultSet rs = pb.executeQuery("SELECT * FROM Publisher");
        String id, name, url;
        System.out.println("Publisher_ID Name URL");

        try {
            while (rs.next()) {
                id = rs.getString("Publisher_ID");
                name = rs.getString("name");
                url = rs.getString("url");
                System.out.println(id + " " + name + " " + url);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }

        pb.close();
    }
}

// !!!!!!!!!!!!!!!!!!!!!!!!! NOTE !!!!!!!!!!!!!!!!!!!!!!!!!!!

>java com.Publisher // OK!

http://localhost:8080/publisher.jsp will report error for open(url,
user, passwd) return false;

Reply to this Message

Allen - 02 Aug 2006 07:54 GMT

// My platform is jre1.5.0_06, Tomcat 5.5
// JSP file

<%@ page language="java" import="java.sql.*" %>
<jsp:useBean id="pb" class="com.Publisher" scope="page" />
<html>
<head>
<title>List of Publisher</title>
</head>
<body>
<%!
    String id, name, url;
%>
<h1>Publisher_ID Name URL</h1>
<% try {
        if (!pb.open("jdbc:odbc:Publisher", "user", "user")) {
            out.print("error");
        }

        ResultSet rs = pb.executeQuery("SELECT * FROM Publisher");
        if (rs != null) {
            while (rs.next()) {
                id = rs.getString("Publisher_ID");
                name = rs.getString("name");
                url = rs.getString("url");
%>
<h2>
                <%= id + " " + name + " " + url %>
</h2>
<%            }
            rs.close();
        }
    } catch (SQLException e) {
    }
%>
</body>
</html>

Reply to this Message

Allen - 02 Aug 2006 08:45 GMT

java.sql.SQLException: [Microsoft][ODBC Driver Manager] not found data
source name and not spcified default driver
    at sun.jdbc.odbc.JdbcOdbc.createSQLException(Unknown Source)
    at sun.jdbc.odbc.JdbcOdbc.standardError(Unknown Source)
    at sun.jdbc.odbc.JdbcOdbc.SQLDriverConnect(Unknown Source)
    at sun.jdbc.odbc.JdbcOdbcConnection.initialize(Unknown Source)
    at sun.jdbc.odbc.JdbcOdbcDriver.connect(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at com.Publisher.open(Publisher.java:19)
    at org.apache.jsp.publisher_jsp._jspService(publisher_jsp.java:65)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332)
    at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
    at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
    at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
    at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
    at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
    at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
    at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
    at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
    at
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
    at
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
    at
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
    at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
    at java.lang.Thread.run(Unknown Source)

Reply to this Message

Allen - 02 Aug 2006 09:40 GMT

Yes. I found it was caused by DriverManager.getConnection(url, user,
passwd).

When run java class directly, it can use odbc configured data source,
i.e.
database url can be "jdbc:odbc:Publisher".

But in JavaBean, url can only be used as
"jdbc:odbc:driver={Microsoft Access Driver
(*.mdb)};DBQ=E:/publisher.mdb".

Why?

Reply to this Message

Why JavaBean load jdbc driver failed?

Free Magazines