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How to have gap between the frame and a component?

I'm trying practice my GUI and I am having troubles putting gap between component and the frame.
The picture above is what I have so far. But I really want to put a gap between the left side of the frame and "label1".
private void initialize() {
frame = new JFrame();
frame.setTitle("WINDOW");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 300);
panel = new JPanel();
panel.setLayout(new BorderLayout());
bottomPanel = new JPanel();
bottomPanel.setLayout(new GridLayout(1, 5));
l1 = new JLabel("Label1");
l2 = new JLabel("Label2");
l3 = new JLabel("Label3");
l4 = new JLabel("Label4");
l5 = new JLabel("Label5");
bottomPanel.add(l1);
bottomPanel.add(l2);
bottomPanel.add(l3);
bottomPanel.add(l4);
bottomPanel.add(l5);
panel.add(bottomPanel, BorderLayout.SOUTH);
frame.add(panel);
}
Above is part my code. I tried doing:
bottomPanel.setLayout(new GridLayout(1, 5, -20, 0));
to put some horizontal gap but that only added gap between the components. That didn't move "label1" away from the frame at all. Is there any other way of doing this? I am very new to Java so I don't really know much of the other tricks. I would appreciate any help! Thank you!

The other answers are fudges that won't achieve the desired effect when the GUI is resized. Instead use:
JLabel.setHorizontalAlignment(SwingConstants.CENTER);
By centering the text within the JLabel, combined with GridLayout stretching the components to the full width of the cell, each label will have as much space either side as the GUI can allow. E.G. here is the effect when the GUI is at minimum size.
And when stretched wider:
(The red border is added to show the bounds of each label.)

Add a Border to the panel:
bottomPanel = new JPanel();
bottomPanel.setBorder( new EmptyBorder(0, 10, 0, 0) );
Read the section from the Swing tutorial on How to Use Borders for more information about the different borders you can create.

Try the following:
bottomPanel.add(javax.swing.Box.createHorizontalStrut(10));

Adding components dynamically to the JPanel changing components size

I am trying to add combo box to the JPanel dynamically but the combo box occupying entire panel.According to the combo box count the size of the combo boxes are changing but I want fixed size of the combo box and I need to create the combo boxes one by one means below of another combo /in a new line.
How to set the location of the components in a panel.
JComboBox startDate = new JComboBox();
startDate.setPreferredSize(new Dimension(80,25));
jPanelStartDate.add(startDate);
jPanelStartDate.setLayout(new GridLayout(0, 3, 10, 10));
jPanelStartDate.revalidate();

Ok, you have more than one option. You can use a BoxLayout with a Y_Axis and a rigid area or you can use the more advanced, complex and dynamic GridBagLayout. The following is an example with a BoxLayout and rigid areas.
JFrame frame = new JFrame("Test");
JPanel panel = new JPanel();
BoxLayout boxLayout = new BoxLayout(panel, BoxLayout.Y_AXIS);
panel.setLayout(boxLayout);
for(int index = 0; index < 5; ++index){
JComboBox<String> box = new JComboBox<>(new String[]{"a", "b", "c"});
box.setMaximumSize(new Dimension(50, 50));
box.setMinimumSize(new Dimension(50, 50));
panel.add(box);
panel.add(Box.createRigidArea(new Dimension(10, 10)));
}
frame.setContentPane(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(new Dimension(300, 300));
frame.setVisible(true);
You can change the dimensions, specially of the rigid area to adjust the spaces and the sizes of the components according to your needs.

Align two panels next to eachother

I am currently trying to create a script editor. But the lineNumber JPanel is not top aligned next to the JTextArea. The lineNumber JPanel appears at the center on the right side of the JTextArea.
It looks like this:
This is the class which instantiates both of these components:
private ScriptEditor() {
((FlowLayout) this.getLayout()).setVgap(0);
((FlowLayout) this.getLayout()).setHgap(0);
//This is the lineNumber JPanel which has no LayoutManager set.
lineNumPanel = new LineNumberPanel();
//I tried setAlignmentY but it did not work
lineNumPanel.setAlignmentY(TOP_ALIGNMENT);
//The text area.
scriptArea = new JTextArea(22,15);
scriptArea.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 15));
scriptArea.setMargin(new Insets(3, 10, 3, 10));
//This JPanel contains the two components: lineNumber JPanel and the JTextArea
JPanel temp = new JPanel();
temp.add(lineNumPanel);
temp.add(scriptArea);
//Set the scrollPane
JScrollPane scrollPane = new JScrollPane(temp);
scrollPane.setPreferredSize(new Dimension(width, height));
//Add the scrollPane to this JPanel.
add(scrollPane);
}

JPanel temp = new JPanel();
By default a JPanel uses a FlowLayout. a FlowLayout vertically centers the components added to the panel. If you don't like this behaviour then try a different layout manager like a horizontal BoxLayout, which will allow you to align the component at the top/center/bottom depending on the components vertical alignment.
However, using a JPanel is not the best approach. Instead you should be adding the line number component to the row header of the scroll pane. See Text Component Line Number for an example of this approach.

JScrollPane increases its size

I have a panel which is divided by two parts with BoxLayout.X_AXIS:
public TabsPanel() {
setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
add(createLeftPanel());
add(createRightPanel());
}
Each left and right panels have the following structure: an outer panel with BorderLayout, and an inner panel in BorderLayout.CENTER of the outer panel, which in its turn has BoxLayout.Y_AXIS and several components from top to bottom. The right panel has JTextArea with JScrollPane as one of its components:
protected JPanel createRightPanel() {
JPanel pane = new JPanel();
pane.setLayout(new BorderLayout());
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
JTextArea label = createLabel();
JScrollPane scroll = new JScrollPane(label);
scroll.setMaximumSize(new Dimension(500, 200));
panel.add(Box.createRigidArea(new Dimension(0,106)));
panel.add(scroll);
JPanel panel_buttons = new JPanel();
panel_buttons.setLayout(new BoxLayout(panel_buttons, BoxLayout.LINE_AXIS));
panel_buttons.setAlignmentX(Component.CENTER_ALIGNMENT);
Font font_text = new Font("Georgia", Font.PLAIN, 20);
JButton[] buttons = new JButton[2];
buttons[0] = new JButton("Clear");
buttons[1] = new JButton("Exit");
for (int i = 0; i < buttons.length; i++) {
buttons[i].setMaximumSize(new Dimension(120, 40));
buttons[i].setFont(font_text);
panel_buttons.add(buttons[i]);
if (i == 0)
panel_buttons.add(Box.createRigidArea(new Dimension(40, 0)));
buttons[i].addActionListener(new TextActionListener(label));
}
panel.add(Box.createRigidArea(new Dimension(0,20)));
panel.add(panel_buttons);
pane.add(panel, BorderLayout.CENTER);
return pane;
}
When text goes beyond the borders, scroll bars appear and I can move them and read the text. Looks like everything is ok, but when I either click any place outside the scroll pane or even just move the pointer, the scroll pane moves to the left and grows down. It doesn't change its width, but it shifts to the left because the area between it and the right panel's borders increases. Accordingly, size of the left panel shrinks. When I clear the text area and again either click or move the pointer, it is back to its normal size.
What is the reason its height grows and its left and right margins increase? What am I doing wrong?
UPDATE. I've found the problem. The thing is that I didn't create JTextArea correctly. I initialized it without parameters:
JTextArea text = new JTextArea("Some initial text");
Now I have rewritten:
JTextArea text = new JTextArea(5,10);
It is now shifted to the left by about 5 mm and do not changes its height. Still not perfect, but looks like I am on the right track.
Thank you everybody for your help!

BoxLayout accepting Min, Max and PreferredSize override those methods for JPanel
use JSPlitPane, there you can to hide Divider

2 steps to correct:
Set the size of the JTextArea: JTextArea text = new JTextArea(row, col);
Still shifts to the left by the size of the vertical bar:
either add ChangeListener to adjust the size of the JScrollPane
scroll.getViewport().addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
if (scroll.getVerticalScrollBar().isVisible())
scroll.setPreferredSize(480, 200);
}
}
});
or add scroll.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);

Vertical alignment of components of jpanels using GridLayout

I am making KenKen as my term project using java swing library. For alignment I have used gridbag and gridlayout, But now i want to add one more component of JPanel to the UI. These screenshots will make the problem more clear:
Now I select the grid cell to which i want to add respective candidates of in the left most panel.
It disturbs the adjacent alignments of the grid and panels.
Here are the panels with their respective layouts:
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new GridLayout(1, 4, 5, 5));
buttonPanel.setPreferredSize(new Dimension(20,40));
buttonPanel.add(undoButton);
buttonPanel.add(redoButton);
buttonPanel.add(eraseButton);
buttonPanel.add(hintButton);
JPanel cellPanel = new JPanel();
cellPanel.setName("cellPanel");
cellPanel.setLayout(new GridLayout(pSize, pSize, 0, 0));
JPanel numPanel = new JPanel();
numPanel.setName("numPanel");
numPanel.setLayout(new GridLayout(1,1,5,5));
numPanel.setPreferredSize((new Dimension(50,60)));
JPanel candPanel = new JPanel();
candPanel.setName("candidatesPanel");
JLabel candidates = new JLabel("Candidates");
candidates.setFont(new Font("Courier New", Font.ITALIC, 14));
candidates.setForeground(Color.GRAY);
candPanel.setLayout(new GridLayout(0,1));
candPanel.add(candidates);
Then it all goes into the content panel:
content.add(buttonPanel, pos.nextCol().expandW());
content.add(candPanel, pos.nextRow());
content.add(new Gap(GAP) , pos.nextRow()); // Add a gap below
content.add(cellPanel, pos.nextCol());
content.add(numPanel,pos.nextCol().expandW());
The buttons are all generated on runtime, and they are added to the candPanel in an action listener.

You appear to be using a GridBagConstraints subclass of which I am unaware (variable pos), though I can guess its function from context.
Assuming your problem is that you want the candidates panel to be to the left of the cellPanel, and not above it, you need to swap the lines which add the candPanel and the new Gap(GAP) as follows:
content.add(buttonPanel, pos.nextCol().expandW());
content.add(new Gap(GAP), pos.nextRow()); // These two lines
content.add(candPanel, pos.nextRow()); // swapped over
content.add(cellPanel, pos.nextCol());
content.add(numPanel,pos.nextCol().expandW());