package dbutil;
     import java.sql.*;

        public class DBConnect {
            Connection conn = null;
            public DBConnect() throws Exception {
               Class.forName("oracle.jdbc.OracleDriver");
                  Connection conn =
                   DriverManager.getConnection("jdbc:oracle:thin:
                     @localhost:1521:XE","system","9424705385");

      }
           public void queryExecuter(String sql) throws Exception
     {
    //for insert, update and Delete DML
    Statement stat = conn.createStatement();
    stat.execute(sql);
    stat.close();
    conn.close();
     }

      public ResultSet queryReturner(String sql) throws Exception
            {        //select statement
    Statement stat = conn.createStatement();
    ResultSet rs = stat.executeQuery(sql);
    return rs;
    }
    }

package dbutil;
   import java.sql.*;

   public class RegisterUser {

   public void insertUser
        (String email,String pass,String name,String mobile)
                throws Exception
        {
            String sql = "insert into webreg
         value('"+email+"','"+pass+"','"+name+"','"+mobile+"')";
            DBConnect x = new DBConnect();
            x.queryExecuter(sql); //line showing error
        }
        public ResultSet getAllUser() throws Exception

        {
            DBConnect x = new DBConnect();
            ResultSet rs = x.queryReturner("select * from webreg"); //line
            showing error
            return rs;

        }

      }