java.lang.ClassNotFoundException: com.microsoft.jdbc.sqlserver.SQLServerDriver Eclipse3.1 数据库连接测试程序(SQL Server 2000 Driver for JDBC Service Pack 3 安装测试)

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1.
安装:SQL Server 2000 Driver for JDBC Service Pack 3
下载安装JDBC SP3
http://www.microsoft.com/downloads/details.aspx?familyid=07287B11-0502-461A-B138-2AA54BFDC03A&displaylang=en
里面的SetUp.exe
按照提示安装可以了.成功后有三个文件要使用:
c:\program files\Microsoft SQL Server 2000 Driver for JDBC\lib\msbase.jar
c:\program files\Microsoft SQL Server 2000 Driver for JDBC\lib\msutil.jar
c:\program files\Microsoft SQL Server 2000 Driver for JDBC\lib\mssqlserver.jar

2.测试代码
新建类文件Connect.java.

package test;
import java.*;
import java.sql.Driver;
public class Connect{
     private java.sql.Connection con = null;
     private final String url = "jdbc:microsoft:sqlserver://";
     private final String serverName= "localhost";
     private final String portNumber = "1433";
     private final String databaseName= "DBtest";
     private final String userName = "sa";
     private final String password = "123456";
     // Informs the driver to use server a side-cursor,
     // which permits more than one active statement
     // on a connection.
     private final String selectMethod = "cursor";

// Constructor
public Connect(){}

private String getConnectionUrl(){
return url+serverName+":"+portNumber+";databaseName="+databaseName+";selectMethod="+selectMethod+";";

}

     private java.sql.Connection getConnection(){
          try{
               Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
               con = java.sql.DriverManager.getConnection(getConnectionUrl(),userName,password);
               if(con!=null) System.out.println("Connection Successful!");
          }catch(Exception e){
               e.printStackTrace();
               System.out.println("Error Trace in getConnection() : " + e.getMessage());
         }
          return con;
      }

     /*
          Display the driver properties, database details
     */

     public void displayDbProperties(){
          java.sql.DatabaseMetaData dm = null;
          java.sql.ResultSet rs = null;
          try{
               con= this.getConnection();
               if(con!=null){
                    dm = con.getMetaData();
                    System.out.println("Driver Information");
                    System.out.println("\tDriver Name: "+ dm.getDriverName());
                    System.out.println("\tDriver Version: "+ dm.getDriverVersion ());
                    System.out.println("\nDatabase Information ");
                    System.out.println("\tDatabase Name: "+ dm.getDatabaseProductName());
                    System.out.println("\tDatabase Version: "+ dm.getDatabaseProductVersion());
                    System.out.println("Avalilable Catalogs ");
                    rs = dm.getCatalogs();
                    while(rs.next()){
                         System.out.println("\tcatalog: "+ rs.getString(1));
                    }
                    rs.close();
                    rs = null;
                    closeConnection();
               }else System.out.println("Error: No active Connection");
          }catch(Exception e){
               e.printStackTrace();
          }
          dm=null;
     }

     private void closeConnection(){
          try{
               if(con!=null)
                    con.close();
               con=null;
          }catch(Exception e){
               e.printStackTrace();
          }
     }
     public static void main(String[] args) throws Exception
       {
          Connect myDbTest = new Connect();
          myDbTest.displayDbProperties();
       }
}
代码来源:
http://support.microsoft.com/default.aspx?scid=kb;zh-cn;313100
------------------------------------------
成功后控制台输出:
Connection Successful!
Driver Information
Driver Name: SQLServer
Driver Version: 2.2.0040

Database Information
Database Name: Microsoft SQL Server
Database Version: Microsoft SQL Server 2000 - 8.00.760 (Intel X86)
Dec 17 2002 14:22:05
Copyright (c) 1988-2003 Microsoft Corporation
Enterprise Edition on Windows NT 5.2 (Build 3790: )

Avalilable Catalogs
catalog: DBtest
...........

3.问题:
在测试中控制台老输出下面的错误!
找资料找了很久.都说把jdbc安装后的三个jar文件的路径放进环境变量里可以了但我试了不行的!
java.lang.ClassNotFoundException: com.microsoft.jdbc.sqlserver.SQLServerDriver
.........
Error Trace in getConnection() : com.microsoft.jdbc.sqlserver.SQLServerDriver
Error: No active Connection

请教了别人才找到办法:
包资源管理器-->包名右键"构建路径"-->配置构建路径-->java构建路径-->库-->添加外部JAR
把那三个JAR选择进去就可以了.

添加后三个JDBC文件就有了.