JPanel

The JPanel class provides general-purpose containers for lightweight components.
You can refer to How to Use Panels.

What is the difference between JPanel and JFrame?

You can add JPanel to a JFrame. You can't add JFrame to other containers.

What's so good about JPanel ?

You can use it to create more complicated components.
Use as an intermediate container to contain other components.

Titanic.java

You can get the program here.
Download the titanic picture here .
titanicframe

   1:import java.awt.*;
   2:import javax.swing.*;
   3:
   4:public class Titanic extends JFrame {
   5:    private JPanel panel;
   6:    private JLabel movieLabel;
   7:    private JLabel directorLabel;
   8:    private JLabel actorLabel;
   9:    private JLabel actressLabel;
  10:    private JLabel moviePictureLabel;
  11:    private Container contentPane;
  12:    public Titanic() {
  13:        super("Titanic"); // set the title to titanic;
  14:        contentPane = getContentPane();
  15:        setUpLabels(); // set up the labels, see the method below
  16:        int col = 1;
  17:        // create a panel with GridLayout
  18:        panel = new JPanel(new GridLayout(0,col));
  19:        // add labels to the panel
  20:        panel.add(movieLabel);
  21:        panel.add(directorLabel);
  22:        panel.add(actorLabel);
  23:        panel.add(actressLabel);
  24:        // and panel to west side of the frame
  25:        contentPane.add(panel, BorderLayout.WEST);
  26:        // add moviePictureLabel to the center of the frame
  27:        contentPane.add(moviePictureLabel);
  28:        
  29:    }
  30:    
  31:    private void setUpLabels() {
  32:        movieLabel = new JLabel("Movie : Titanic");
  33:        Color foregroundColor = Color.red;
  34:        Color backgroundColor = Color.blue;
  35:        movieLabel.setOpaque(true); // set the label opaque means 
  36:                                    // the label  ignores the
  37:                                    // background for the parent container. 
  38:                                     // that make it more 
  39:                                    // efficent to draw
  40:        movieLabel.setForeground(foregroundColor); // set the color of the text
  41:        movieLabel.setBackground(backgroundColor); // setbackground color
  42:        
  43:        directorLabel = new JLabel("Director : James Cameron");
  44:        directorLabel.setOpaque(true);
  45:        directorLabel.setForeground(foregroundColor); // set the color of the text
  46:        directorLabel.setBackground(backgroundColor); // setbackground color
  47:        
  48:        actorLabel = new JLabel("Actor :  Leonardo DiCaprio");
  49:        actorLabel.setOpaque(true);
  50:        actorLabel.setForeground(foregroundColor); // set the color of the text
  51:        actorLabel.setBackground(backgroundColor); // setbackground color
  52:        
  53:        actressLabel = new JLabel("Actress : Kate Winslet");
  54:        actressLabel.setOpaque(true);
  55:        actressLabel.setForeground(foregroundColor); // set the color of the text
  56:        actressLabel.setBackground(backgroundColor); // setbackground color
  57:        
  58:        moviePictureLabel = new JLabel(new ImageIcon("titanic.jpg"));
  59:        moviePictureLabel.setOpaque(true);
  60:        moviePictureLabel.setBackground(backgroundColor); // setbackground color
  61:    }
  62:        
  63:    public static void main(String[] args) {
  64:        Titanic t = new Titanic();
  65:        t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  66:        t.pack();
  67:        t.setVisible(true);
  68:    }   
  69:        
  70:}  
  71:

Explanation :

line 5: declares a JPanel.
line 6-10: declares different labals.
line 18 : constructor for JPanel. the layout is set to GridLayout with 1 column.
line 20 - 23 : add labels to the panel.
line 31 - 61 : initial the labels, set background color by setBackground, set foreground color by setForeground and also use setOpaque(true) to set it opaque (not transparent).
I don't specific a layout for JFrame. The default layout for JFrame is BorderLayout.

Setting the Layout Manager

Like other containers, a panel uses a layout manager to position and size its components. By default, a panel's layout manager is an instance of FlowLayout, which places the panel's contents in a row. You can easily make a panel use any other layout manager by invoking the setLayout method or specifying a layout manager when creating the panel. Here is an example of the first approach:

JPanel aPanel = new JPanel();
aPanel.setLayout(new BorderLayout());

Here is an example of setting the layout manager at instantiation:

JPanel aPanel = new JPanel(new BorderLayout());

Adding Components

When you add components to a panel, you use the add method. Exactly which arguments you specify to the add method depend on which layout manager the panel uses. When the layout manager is FlowLayout, BoxLayout, GridLayout, or GridBagLayout, you'll typically use the one-argument add method, like this:

aFlowPanel.add(aComponent);
aFlowPanel.add(anotherComponent);

When the layout manager is BorderLayout, you need to provide a second argument specifying the added component's position within the panel. For example:

aBorderPanel.add(aComponent, BorderLayout.CENTER);
aBorderPanel.add(anotherComponent, BorderLayout.SOUTH);

The Panel API

Creating a `JPanel`
Constructor	Purpose
`JPanel() JPanel(LayoutManager)`	Create a panel. The `LayoutManager` parameter provides a layout manager for the new panel. By default, a panel uses a `FlowLayout` to lay out its components.

Managing a Container's Components
Method Purpose

void add(Component) void add(Component, int) Add the specified component to the panel. When present, the int parameter is the index of the component within the container. By default, the first component added is at index 0, the second is at index 1, and so on.

void remove(Component) void remove(int) void removeAll() Remove the specified component(s).

Managing a Container's Components
Method	Purpose
`void add(Component) void add(Component, int)`	Add the specified component to the panel. When present, the `int` parameter is the index of the component within the container. By default, the first component added is at index 0, the second is at index 1, and so on.
`void remove(Component) void remove(int) void removeAll()`	Remove the specified component(s).

Setting/Getting the Layout Manager
Method Purpose

void setLayout(LayoutManager) LayoutManager getLayout() Set or get the layout manager for this panel. The layout manager is responsible for positioning the panel's components within the panel's bounds according to some philosophy.