public static Set getForeignKeyColumns(Connection c, String catalog, String schema, String table) throws SQLException {      
                DatabaseMetaData dmd = c.getMetaData();      
                ResultSet rs = null;      
                HashSet columns = new HashSet();   
                try {      
                    rs = dmd.getImportedKeys(catalog, schema, table);      
                      
                    while (rs.next()) {      
                        columns.add(rs.getString(8));      
                   }      
                        
                }catch(Exception e){
                    e.printStackTrace();
                }
                finally {      
                    if (rs != null) rs.close();
                    return columns; 
                }      
            }