Help: error: can not find the main class!

Question

when I run the class, the following error message comes up:
java.lang.NoClassDefFoundError: j2sdk1/4/1
and also a dialogue window (title is "java virtual machine launcher") comes up: could not find the main class, program will exit! After I click ok button, another error message shows up: Exception in thread "main" .
Could anyone help me figure out what's wrong with my program? If you need any other informaiton, please email me: [email protected], Thanks a lot!!!

Answer 1

Hi, thank you very much for your reply. Here is the program:
import java.sql.*;
import java.io.*;
import java.util.*;
import java.lang.Object;
public class CatalogConnect{
Statement stmt, st, mast, ques;
ResultSet rset, orgset,maset, quesset;
String organization = null;
String sponsor = null;
String interMethod = null;
String year = null;
String collection = null;
String country = null;
String countryName = null;
String archNO = null;
String codeBook = null;
String td = null;
String todate = null;
String month = null;
int studyID, quesID, sponsorID, orgID;
public CatalogConnect(){
connect();
makeXMLFile();
public CatalogConnect(String codeBk){
codeBook = codeBk;
connect();
makeXMLFile();
public void connect(){
try{
// DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
// Class.forName(oracle.jdbc.driver.OracleDriver);
Connection conn =
DriverManager.getConnection ("jdbc:oracle:thin:@137.99.37.146:1521:ipoll",
"catalog", "catalog");
stmt = conn.createStatement ();
st = conn.createStatement ();
mast = conn.createStatement ();
Connection conn2 =
DriverManager.getConnection ("jdbc:oracle:thin:@137.99.36.171:1521:ipolljr2",
"catalog", "catalog");
ques = conn2.createStatement ();
} catch(SQLException ex) {
System.err.println("SQLException: " + ex.getMessage());
public static void main (String args[]){
CatalogConnect c = new CatalogConnect();
public void makeXMLFile() {
PrintWriter out = null;