问题
Could anyone suggest me how to store .TIF formatted image to ImageIcon and add this image to list model? I tried this but gives me java.lang.NullPointerException.
public static void main(String[] args) throws Exception {
String path = "C:\\project\\aimages";
JFrame frame = new JFrame();
frame.setSize(500, 500);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
File folder = new File(path);
File[] listOfFiles = folder.listFiles();
DefaultListModel listModel = new DefaultListModel();
System.out.println("listOfFiles.length="+listOfFiles.length);
int count = 0;
for (int i = 0; i < listOfFiles.length; i++) {
//System.out.println("check path"+listOfFiles[i]);
String name = listOfFiles[i].toString();
System.out.println("name"+name);
// load only JPEGs
if (name.endsWith("jpg") || name.endsWith("JPG")|| name.endsWith("tif") || name.endsWith("TIF")) {
if(name.endsWith("tif") || name.endsWith("TIF"))
{
BufferedImage image = ImageIO.read(listOfFiles[i]);
BufferedImage convertedImage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_RGB);
ImageIcon ii = new ImageIcon(image);
Image img1 = ii.getImage();
Image newimg = img1.getScaledInstance(75, 75, java.awt.Image.SCALE_SMOOTH);
ImageIcon newIcon = new ImageIcon(img1);
listModel.add(count++, newIcon);
}
else
{
ImageIcon ii = new ImageIcon(ImageIO.read(listOfFiles[i]));
Image img1 = ii.getImage();
Image newimg = img1.getScaledInstance(75, 75, java.awt.Image.SCALE_SMOOTH);
ImageIcon newIcon = new ImageIcon(newimg);
listModel.add(count++, newIcon);
}
}
}
JList p2 = new JList(listModel);
}
}
here i had edited my code and this is my error msg Exception in thread "main" java.lang.NullPointerException at javax.swing.ImageIcon.(ImageIcon.java:228) at ListImage1.main(ListImage1.java:48)
回答1:
If the TIFF is an application resource, probably better to convert it to JPG or PNG.
OTOH, I believe that JAI offers support for reading TIFF.
回答2:
Seems like .TIF is not supported by ImageIO. Do have a look at the formats supported by ImageIO by using ImageIO.getReaderFormatNames(), when i did that I got the output as :
C:\Mine\JAVA\J2SE\classes>java TestBorder
jpg
BMP
bmp
JPG
jpeg
wbmp
png
JPEG
PNG
WBMP
GIF
gif
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(ImageIcon.java:228)
at TestBorder.createAndDisplayGUI(TestBorder.java:34)
at TestBorder.access$100(TestBorder.java:6)
at TestBorder$1.run(TestBorder.java:55)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:705)
at java.awt.EventQueue.access$000(EventQueue.java:101)
at java.awt.EventQueue$3.run(EventQueue.java:666)
at java.awt.EventQueue$3.run(EventQueue.java:664)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:675)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
And this is the program I tried it upon :
import java.awt.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import javax.imageio.ImageIO;
public class TestBorder extends JPanel
{
private static TestBorder testBorder;
public TestBorder()
{
}
private static void createAndDisplayGUI()
{
JFrame frame = new JFrame("FRAME");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
testBorder.setBackground(Color.BLUE);
java.net.URL url = testBorder.getClass().getResource("/image/MARBLES.TIF");
BufferedImage image = null;
try
{
image = ImageIO.read(url);
String[] formatNames = ImageIO.getReaderFormatNames();
for (String s: formatNames)
System.out.println(s);
}
catch(Exception e)
{
e.printStackTrace();
}
ImageIcon imageIcon = new ImageIcon(image);
JLabel label = new JLabel(imageIcon);
testBorder.add(label);
frame.add(testBorder, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
}
public Dimension getPreferredSize()
{
return (new Dimension(300, 300));
}
public static void main(String... args)
{
Runnable runnable = new Runnable()
{
public void run()
{
testBorder = new TestBorder();
createAndDisplayGUI();
}
};
SwingUtilities.invokeLater(runnable);
}
}
Here is the Image that I am using : MARBLES.TIF, do click MARBLES.TIF on that link.
Moreover have a look at what Java Docs have to say for this. Hopefully you might be able to find something useful there.
回答3:
ImageIcon's API says
public ImageIcon(byte[] imageData)
Creates an ImageIcon from an array of bytes which were read from an image file containing a supported image format, such as
GIF,JPEG, or (as of 1.3)PNG. Normally this array is created by reading an image using Class.getResourceAsStream(), but the byte array may also be statically stored in a class. If the resulting image has a "comment" property that is a string, then the string is used as the description of this icon.Parameters: imageData - an array of pixels in an image format supported by the AWT Toolkit, such as GIF, JPEG, or (as of 1.3) PNG See Also: Toolkit.createImage(java.lang.String), getDescription(), Image.getProperty(java.lang.String, java.awt.image.ImageObserver)
there nothing such as support for tiff or raw, contents isn't displayable
- common attribute for Icon and ImageIcon, that don't generating any error or exception,
来源：https://stackoverflow.com/questions/9634472/how-to-set-tif-image-to-imageicon-in-java