已编译的java代码不能运行

以下代码已用javac编译，但用java不能执行，提示错误：“
Exception in thread "main"java.lang.NoClassDefFoundErrorrepTrans/class”不知道是什么问题造成，请指教!
注：tns为fj,Access库表已建
程序文件名：PrepTrans.java
代码如下：
import java.sql.*;
public class PrepTrans
{
public static void main(String args[])
{
String serverName="10.1.1.3";
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
String URL="jdbc:oracle:thin"+serverName+":1521:fj";
Connection connOracle=DriverManager.getConnection(URL,"scott","tiger");
Statement stmt=connOracle.createStatement();
ResultSet rs=stmt.executeQuery("select * from g_czry");

Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection connAccess = DriverManager.getConnection("jdbc.odbc:czryodbc","","");
PreparedStatement pstmt = connAccess.prepareStatement("insert into czry values www.tyc456.com(?,?,?)");;
while(rs.next()){
pstmt.setString(1,rs.getString("dm_czy"));
pstmt.setString(2,rs.getString("xm_czy"));
pstmt.setString(3,rs.getString("dm_dq"));
pstmt.executeUpdate();
}
rs.close();
stmt.close();
pstmt.close();
connOracle.close();
connAccess.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}
}