问从oracle过程调用java的ClassNotFoundException

EN

FUNCTION JavaHefExtract_runSingle (
    p_company_cd        varchar2,
    p_srcConnString     varchar2,
    p_destConnString    varchar2,
    p_mode              number,
    p_period            number
    ) return varchar2
IS
LANGUAGE JAVA
NAME 'HefExtract.DoIt(java.lang.String, java.lang.String, java.lang.String, int, int ) return java.lang.String';

import com.microsoft.sqlserver.jdbc.*;
import java.math.BigInteger;
import java.sql.*;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Enumeration;
import oracle.jdbc.*;
import java.io.*;

public class HefExtract
{

 public static String DoIt(String orgName, String oracleConnstring, String sqlConnstring, int typ, int iPeriod )
    {
        String errMsg = null;
        Connection sqlConn;
        Connection oracleConn;
        try
        {
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
            Class.forName("oracle.jdbc.OracleDriver");
            if (oracleConnstring != null)
                oracleConn = DriverManager.getConnection(oracleConnstring);
            else
                oracleConn = new OracleDriver().defaultConnection();
            sqlConn = DriverManager.getConnection(sqlConnstring);
        } catch (Throwable e1) {
            CharArrayWriter byteSink = new CharArrayWriter();
            e1.printStackTrace(new PrintWriter(byteSink));
            return byteSink.toString();
        }
        return errMsg;
}
}