java怎样设置图片适应容器大小

//你可以试试这个程序 和你说的差不多
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.util.*;

//SplitPaneDemo itself is not a visible component.
public class SplitPaneDemo extends JPanel
implements ListSelectionListener {
private JLabel picture;
private JList list;
private JSplitPane splitPane;
private String[] imageNames = { "Bird", "Cat", "Dog", "Rabbit", "Pig", "dukeWaveRed",
"kathyCosmo", "lainesTongue", "left", "middle", "right", "stickerface"};
public SplitPaneDemo() {

//Create the list of images and put it in a scroll pane.

list = new JList(imageNames);
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
list.setSelectedIndex(0);
list.addListSelectionListener(this);

JScrollPane listScrollPane = new JScrollPane(list);
picture = new JLabel();
picture.setFont(picture.getFont().deriveFont(Font.ITALIC));
picture.setHorizontalAlignment(JLabel.CENTER);

JScrollPane pictureScrollPane = new JScrollPane(picture);

//Create a split pane with the two scroll panes in it.
splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,
listScrollPane, pictureScrollPane);
splitPane.setOneTouchExpandable(true);
splitPane.setDividerLocation(150);

//Provide minimum sizes for the two SplitPaneDemo in the split pane.
Dimension minimumSize = new Dimension(100, 50);
listScrollPane.setMinimumSize(minimumSize);
pictureScrollPane.setMinimumSize(minimumSize);

//Provide a preferred size for the split pane.
splitPane.setPreferredSize(new Dimension(400, 200));
updateLabel(imageNames[list.getSelectedIndex()]);
}

//Listens to the list
public void valueChanged(ListSelectionEvent e) {
JList list = (JList)e.getSource();
updateLabel(imageNames[list.getSelectedIndex()]);
}

//Renders the selected image
protected void updateLabel (String name) {
ImageIcon icon = createImageIcon("images/" + name + ".gif");
picture.setIcon(icon);
if (icon != null) {
picture.setText(null);
} else {
picture.setText("Image not found");
}
}

//Used by SplitPaneDemo2
public JList getImageList() {
return list;
}

public JSplitPane getSplitPane() {
return splitPane;
}

/** Returns an ImageIcon, or null if the path was invalid. */
protected static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = SplitPaneDemo.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
}

/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {

//Create and set up the window.
JFrame frame = new JFrame("SplitPaneDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
SplitPaneDemo splitPaneDemo = new SplitPaneDemo();
frame.getContentPane().add(splitPaneDemo.getSplitPane());

//Display the window.
frame.pack();
frame.setVisible(true);
}

public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}

}

取得容器的宽和高，然后把图片宽和高设置为容器的宽高