JScrollPane not working

Question

It's my first time working on Swing. Probably I am doing something seriously wrong.
I have one tabbed UI where each tab is JPanel (this tab is added to JTabbedPane). I add the number of JTextFields in that JPanel based on user input. I need that JPanel to be scrollable. I have tried following solution:

• Add Jscrollpane to Tab
• Add new Jpanel innerPanel to JscrollPane
• Add all textfields to innerPanel

There are no textFields displayed.

public Tab extends JPanel {

    private TipTailoringTab() {
        JPanel innerPanel =new JPanel();

        int y_cord = 20;
        for (int i = 0; i < USER_INPUT; i++) {
                JTextField TextField = new JTextField();
                TextField.setBounds(42, y_cord, 100, 20);
                innerPanel.add(TextField);
                y_cord = y_cord + 40;
        }
        Dimension preferredSize = new Dimension(400, 600);
        innerPanel.setPreferredSize(preferredSize);
        JScrollPane sPane = new JScrollPane(innerPanel);
        Dimension preferredSize1 = new Dimension(400, 300);
        sPane.setPreferredSize(preferredSize1);
        this.add(sPane);
    }
}

Any Help is much appreciated.

EDIT
for every loop I create One TextField, one Slider, On Label. I want the following structure vertically scrollable when n is large
TextField1 Slider1 Label1
TextField2 Slider2 Label2

TextFieldn Slidern Labeln

Answer 1

Here's a very simple example. I set the preferred sizes so that it forces the scroll bars to become visible/needed. Any questions just ask.

import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.*;

public class Test {
    private static final int USER_INPUT = 10;

    public Test() {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(false);


        JTabbedPane tabs = new JTabbedPane();
        tabs.setTabLayoutPolicy(JTabbedPane.SCROLL_TAB_LAYOUT);
        for (int i = 0; i < 5; i++) {
            tabs.addTab("Tab"+i, new TabPanel());
        }

        frame.add(tabs);
        frame.pack();
        frame.setVisible(true);
    }

    class TabPanel extends JPanel {    
        public TabPanel() {
            JPanel innerPanel = new JPanel();
            innerPanel.setLayout(new BoxLayout(innerPanel, BoxLayout.Y_AXIS));

            for (int i = 0; i < USER_INPUT; i++) {
                JPanel p = new JPanel(new BorderLayout());
                JLabel label = new JLabel("Label"+i);
                JTextField textArea = new JTextField();
                p.add(label, BorderLayout.NORTH);
                p.add(textArea, BorderLayout.CENTER);
                innerPanel.add(p);
            }

            JScrollPane scrollPane = new JScrollPane(innerPanel);
            scrollPane.setPreferredSize(new Dimension(400, 200));
            this.add(scrollPane);
        }
    }

    public static void main(String[] args) {
        new Test();
    }
}