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JScrollPane components do not appear

I'm trying to put some components inside of a JScrollPane but every time I launch my program they don't appear. I just started learning about GUIs today so I figure I missed something small but no matter where I look online I can't find an answer. The only thing that appears is the JScrollPane itself.
class MainFrame extends JFrame{
public MainFrame(String title){
//Main Frame Stuff
super(title);
setSize(655, 480);
setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
//Layout
FlowLayout flow = new FlowLayout();
setLayout(flow);
//Components
JButton spam_button = new JButton("Print");
JLabel label = new JLabel("What do you want to print?",
JLabel.LEFT);
JTextField user_input = new JTextField("Type Here", 20);
//Scroll Pane
JScrollPane scroll_pane = new JScrollPane(
ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
scroll_pane.setPreferredSize(new Dimension(640, 390));
//Adding to Scroll
scroll_pane.add(label);
scroll_pane.add(user_input);
scroll_pane.add(spam_button);
//Adding to the Main Frame
add(scroll_pane);
//Visibility
setVisible(true);
}
}
The point of the program is to print whatever you type 100 times but I haven't gotten that far yet because I've been hung up on this scroll problem. When I finally get things to show up in the scroll pane I'm going to move those three components to a JPanel above the scroll pane and then I'm going to add the 100 words to the scroll pane so that you can scroll through it.

I just started learning about GUIs today
So the first place to start is with the Swing tutorial. There is plenty of demo code to download and test and modify.
scroll_pane.add(label);
scroll_pane.add(user_input);
scroll_pane.add(spam_button);
A JScrollPane is not like a JPanel:
you don't add components directly to the scroll panel. You add a component to the viewport of the scroll pane
only a single component can be added to the viewport.
So your code should be something like:
JPanel panel = new JPanel();
panel.add(label);
panel.add(user_input);
panel.add(spam_button);
scrollPane.setViewportView( panel );

BoxLayout Displaying Incorrectly

I'm trying to create a pretty simple application that has a JSplitPane (which is divided into a JTabbedPane and a JPanel) above a status bar panel. I want to use a simple layout (i.e. BoxLayout, FlowLayout, or BorderLayout), but I've tried and they all give me the same error. I've simplified the code as much as possible to show the error.
The error is that there should only be 2 regions in the main box layout (the frame): a top (with the JSplitPane, which has the black border) and a bottom (with the JPanel status bar). However, when I add the status bar, a third region is created in the upper left that contains nothing. Any ideas on how to get rid of it?
public static void main(String[] args) {
JFrame frame = new JFrame("Application");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new BoxLayout(frame.getContentPane(), BoxLayout.Y_AXIS));
// Create left side of the application
JTabbedPane tabby = new JTabbedPane(JTabbedPane.LEFT);
// Create right side of the application
JPanel rightPanel = new JPanel(new BorderLayout());
// Create the status bar at the bottom
JPanel statusBar = new JPanel(new BorderLayout());
JPanel statusBarPanel = new JPanel();
statusBarLabel = new JLabel("Status Bar");
statusBarPanel.add(statusBarLabel);
parent.add(statusBarPanel);
JSplitPane mainPain = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, tabby, rightPanel);
frame.add(mainPain);
frame.add(statusBar);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);

I'm trying to create a pretty simple application that has a JSplitPane (which is divided into a JTabbedPane and a JPanel) above a status bar panel.
Normally you would just use the default BorderLayout of the frame and then do:
frame.add(splitPane, BorderLayout.CENTER);
frame.add(statusBar, BorderLayout.PAGE_END);
A status bar is typically one or more labels that display information so they are display in a fixed size at the bottom.
The other panel will then contain the main components of the application. These components will then get any extra space available to the frame as it is resized.
but I've tried and they all give me the same error
parent.add(statusBarPanel);
The variable "parent" doesn't exist. Get rid of it. Add the status bar to the frame as shown above.

not sure if thats it, but it seems, like you add 2 Panels when adding the Statusbar.
You got a statusBarPanel which is added to "parent", and statusBar, which is added to the frame itself. Maybe thats your 3rd Panel.

JTabbedPane in JPanel?

I have a simple problem when I want to add tabs in my jpanel. The alignment of the tabs get horizontal instead of vertical, wich looks like crap =/.
It looks like this:
If I discard the panel instead and add the tabbedPane directly to the frame, everything works fine.
If you uncomment the three lines of code and remove the getContentPane().add(jtp); you can reproduce my probleme.
working Code:
public class TabbedPane extends JFrame
{
public TabbedPane()
{
setTitle("Tabbed Pane");
setSize(300, 300); // set size so the user can "see" it
JTabbedPane jtp = new JTabbedPane();
// JPanel panel = new JPanel();//uncomment all three lines
// panel.add(jtp);
// getContentPane().add(panel);
getContentPane().add(jtp);//remove me
JPanel jp1 = new JPanel();// This will create the first tab
JPanel jp2 = new JPanel();// This will create the second tab
JLabel label1 = new JLabel();
label1.setText("This is Tab 1");
jp1.add(label1);
jtp.addTab("Tab1", jp1);
jtp.addTab("Tab2", jp2);
JButton test = new JButton("Press");
jp2.add(test);
setVisible(true); // otherwise you won't "see" it
}
public static void main(String[] args)
{
TabbedPane tab = new TabbedPane();
}
}
Thanks a lot!

If I discard the panel instead and add the tabbedPane directly to the frame, everything works fine.
The default layout of JPanel is FlowLayout, which "lets each component assume its natural (preferred) size." The default layout of JFrame is BorderLayout, the CENTER of which ignores preferred size. In either case, invoking setSize() precludes the layout from functioning initially; re-size the frame to see the effect. Instead, use pack(), which "Causes this Window to be sized to fit the preferred size and layouts of its subcomponents."
setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
setVisible(true); // otherwise you won't "see" it

There are many things I would change in that code, starting with the recommendations of #trashgod. OTOH this is the minimal change needed in order to stretch the tabbed pane to the width/height of the parent container.
// give the panel a layout that will stretch components to available space
JPanel panel = new JPanel(new GridLayout());//uncomment all three lines
panel.add(jtp);
getContentPane().add(panel);
//getContentPane().add(jtp);//remove me
For more details see this answer.

Well firstly you can try this:
JPanel panel = new JPanel();//uncomment all three lines
panel.setLayout(new GridLayout());
JPanel jp1 = new JPanel();// This will create the first tab
JPanel jp2 = new JPanel();// This will create the second tab
JLabel label1 = new JLabel();
label1.setText("This is Tab 1");
jp1.add(label1);
jtp.addTab("Tab1", jp1);
jtp.addTab("Tab2", jp2);
JButton test = new JButton("Press");
jp2.add(test);
getContentPane().add(jtp);
and in the main:
TabbedPane tab = new TabbedPane();
tab.pack();
tab.setVisible(true);
May I suggest using MigLayout to set layouts, it will make your life easier. Hope it helps.

Try GridbagLayout. Once you have mastered it, you can design UI of any sort with this layout.

I agree with prasanth regarding the use of GridBagLayout
I have gone through this problem once and I solved it by adding the JTabbedPaneto the panel via GridBagLayout, make sure you add the JTabbedPane using the ipadx and ipady according to your requirements in your GridBagConstraints object
e.g.
JPanel myPanel=new JPanel();
myPanel.setLayout(new GridBagLayout());
JTabbedPane jTP=new JTabbedPane();
jTP.add("Tab1",new JPanel());//substitute your component instead of "new JPanel"
GridBagConstraints myConstraints=new GridBagConstraints();
myConstraints.ipadx=400;//streches the component being added along x axis - 200 px on both sides
myConstraints.ipady=600;//streches the component being added along y axis - 200 px on both sides
myPanel.add(jTP,myConstraints);
You can adjust both these properties according to what is perfect for your need

How to use the JScrollPane in Java

How can I get the scroller around my JList component in the code given below? It doesn't seem to work properly :(
public class JButtonO extends JFrame{
String[] values = {"henry", "Michael","Uche","John","Ullan","Nelly",
"Ime","Lekan","Austine","jussi","Ossi","Imam","Empo","Austine","Becky",
"Scholar","Ruth", "Anny"};
public JButtonO()
{
super("the button");
this.setSize(400,200);
JPanel panel = new JPanel();
JLabel label = new JLabel("Output Items:");
label.setAlignmentX(1);
label.setAlignmentY(1);
JList conList = new JList(values);
conList.setVisibleRowCount(3);
JScrollPane scroller = new JScrollPane(conList);
panel.add(label);
panel.add(scroller);
panel.add(conList);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.add(panel);
this.setVisible(true);
}

Adding the JScrollPane scroller that includes the JList conList to the JPanel panel is enough.
The mistake is that you are adding the JList a second time.
JScrollPane scroller = new JScrollPane(conList);
panel.add(label);
panel.add(scroller);
panel.add(conList); // <---THIS LINE SHOULD BE DELETED...

Look, I may not answering what you need, because I don´t remember to much of swing layout. I don´t work with it a long time ago...
But removing setting a layout (I remember) on your JPanel it works with this code:
public JButtonO() {
super("the button");
this.setSize(400, 200);
// Create a panel with a borderlayout
JPanel jpanel = new JPanel(new BorderLayout());
JLabel label = new JLabel("Output Items:");
label.setAlignmentX(1);
label.setAlignmentY(1);
// Add Label to top of layout
jpanel.add(label, BorderLayout.NORTH);
JList conList = new JList(values);
conList.setVisibleRowCount(3);
JScrollPane scroller = new JScrollPane(conList);
//AddScroll to center
jpanel.add(scroller);
//Add Panel to JFrame
this.add(jpanel);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
I think the problems is the default layoutmaneger of JPanel. Because of how it works your scroll was not "srink" enough to create scrolls...
Hope it helps, even without too much explanation...
ACTUALLY: After I post the answer I saw your mistake. Now I can explain what is wrong. You already added your JList inside your JScrollPane here:
JScrollPane scroller = new JScrollPane(conList);
But after that you put it inside the JPanel:
panel.add(conList);
this changes where yout JList will be displayed, and let the JScroll empty again. Without components it will be displayed with size 0x0 and will not be draw (even being there).
Now I think I helped =D

The JScrollPane has settings called the scrollbar policies which say when the scrollbars are to be displayed. You can set them using JScrolPane(Component,int,int) constructor, or by calling setVerticalScrollBarPolicy() and setHorizontalScrollBarPolicy(). The default policies are "as needed", meaning the scrollbar is only displayed if the component is too large to display whole. So if your list fits inside the window, the scrolbars will not be visible, but will become visible when you e.g. make the window smaller using the mouse. You can change one or both policies to "always" using corresponding constants in order to make the scrollbar(s) always visible if that's what you need.

Java JPanel inside JScrollPane?

I have a JFrame, in this JFrame I have a JPanel that I draw on, this Panel can be any size and so I placed it into a JScrollpane to let me scroll when the panel is larger than the window screen size.
Unfortunately does not work as I expected:
Making the JFrame window smaller than the JPanel size does not show scroll bars
The JScrollPane size now seems locked to the size of the JPanel I have added to it, where as before it resized to the bounds of it's JFrame window (it still kinda does this but only vertically now?!)
The JPanel seems to assume the size of the JScrollpane regardless of what I set for preferred size
I am sure I'm doing something stupid, if someone could point out what I would be most grateful!
JPanel imageCanvas = new JPanel(); // 'Canvas' to draw on
JScrollPane scrollPane = new JScrollPane();
// set size of 'canvas'
imageCanvas.setMinimumSize(new Dimension(100,100));
// Scroll pane smaller then the size of the canvas so we should get scroll bars right?
scrollPane.setMinimumSize(new Dimension(50,50));
// Add a border to 'canvas'
imageCanvas.setBorder(BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));
scrollPane.setViewportView(imageCanvas);

setPreferredSize() is the trick, setMinimumSize() and even setSize() on the component will be ignored by JScrollPane. Here's a working example using a red border.
import java.awt.*;
import javax.swing.*;
public class Scroller extends JFrame {
public Scroller() throws HeadlessException {
final JPanel panel = new JPanel();
panel.setBorder(BorderFactory.createLineBorder(Color.red));
panel.setPreferredSize(new Dimension(800, 600));
final JScrollPane scroll = new JScrollPane(panel);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
add(scroll, BorderLayout.CENTER);
setSize(300, 300);
setVisible(true);
}
public static void main(final String[] args) throws Exception {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Scroller().setVisible(true);
}
});
}
}

// suggest a size of 'canvas'
_ImageCanvas.setPreferredSize(new Dimension(100,100));
// Scroll pane smaller then the size of the canvas so we should get scroll bars right?
_ScrollPane.setPreferredSize(new Dimension(50,50));
// ..later
_Frame.pack();

Set preferred size on the canvas.
Increase dimensions 100,100 is too small atleast on my computer.
You may want to use new GridLayout(1,1); for you JFrame if you want the scrollpane to expand when you expand the frame.

As far as I remember there are 2 options:
define the preferredSize of _ImageCanvas
create a subclass of JPanel and implement Scrollable: http://docs.oracle.com/javase/7/docs/api/javax/swing/Scrollable.html
For more details, see the Javadoc:
http://docs.oracle.com/javase/7/docs/api/javax/swing/JScrollPane.html

Check out the Scrollable interface, this may help with the sizing issues.
These two method maybe helpful:
boolean getScrollableTracksViewportWidth();
boolean getScrollableTracksViewportHeight();