Problem with ImageIO.read()

Question

I have a problem with loading picture from file to variable Image img. Function ImageIO.read(fileIn) return always null pointer (whereas fileIn!=null). I'm using j2sdk-1_4_2_0. The same problem problem is in WindowsXP SP2 and Fedora 3 64bit.
Here is code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.net.*;
import java.awt.image.*;
import javax.imageio.*;
import java.net.URL;
import javax.imageio.ImageIO;
import java.io.*;
public class Converter extends JPanel implements ActionListener {
JPanel mainPanel, info1Panel,info2Panel,convertionPanel, fSizePanel,displayPanel;
JCheckBox enableConvertion;
JButton selectFile,doIt,close;
JRadioButton size1,size2;
ButtonGroup sizeGroup;
ImageIcon imagePrev;
JRadioButton[] convertion = new JRadioButton[2];
Image img;
JLabel previewLabel;
JFileChooser fc;
File fileIn = new File("10.jpg");
File fileOut;
public Converter() {
// Tworzenie paneli
mainPanel=new JPanel();
mainPanel.setLayout(null);
info1Panel=new JPanel();
info2Panel=new JPanel();
convertionPanel=new JPanel(new BorderLayout());
fSizePanel=new JPanel();
displayPanel= new JPanel();
//Tworzenie pozostalych elementow
enableConvertion = new JCheckBox("Enable JPG <-> PNG");
selectFile = new JButton("Select File");
doIt = new JButton("Do it!");
close= new JButton("Close");
fc = new JFileChooser();
size1 = new JRadioButton("The same resolution");
size2= new JRadioButton("Resize image to target size of file");
JLabel previewLabel = new JLabel();
ButtonGroup sizeGroup = new ButtonGroup();
imagePrev= new ImageIcon();
// proba ulozenia elementow na ramce
Insets insets = mainPanel.getInsets();
Dimension size = selectFile.getPreferredSize();
selectFile.setBounds(15 + insets.left, 15 + insets.top,size.width, size.height);
doIt.setBounds(15 + insets.left,15+5+ insets.top+size.height,size.width, size.height);
close.setBounds(15+insets.left,15+2*(5+size.height)+insets.top,size.width,size.height);
convertionPanel.setBounds(10,150,250,90);
convertionPanel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Convertion"),
BorderFactory.createEmptyBorder(0,5,5,5)));
info1Panel.setBounds(150,10,200,140);
info1Panel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Source File Information"),
BorderFactory.createEmptyBorder(0,5,5,5)));
info2Panel.setBounds(360,10,200,140);
info2Panel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Target File Information"),
BorderFactory.createEmptyBorder(0,5,5,5)));
fSizePanel.setBounds(10, 250, 250, 90);
fSizePanel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("File size"),
BorderFactory.createEmptyBorder(0,5,5,5)));
fSizePanel.setLayout(new GridLayout(2,0));
displayPanel.setBounds(270,150,290,190);
displayPanel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Display"),
BorderFactory.createEmptyBorder(0,5,5,5)));
previewLabel.setHorizontalAlignment(JLabel.CENTER);
previewLabel.setVerticalAlignment(JLabel.CENTER);
previewLabel.setVerticalTextPosition(JLabel.CENTER);
previewLabel.setHorizontalTextPosition(JLabel.CENTER);
previewLabel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createLoweredBevelBorder(),
BorderFactory.createEmptyBorder(5,5,5,5)));
previewLabel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createEmptyBorder(0,0,10,0),
previewLabel.getBorder()));
size1.setSelected(true);
mainPanel.add(info1Panel);
mainPanel.add(info2Panel);
mainPanel.add(convertionPanel);
mainPanel.add(fSizePanel);
mainPanel.add(displayPanel);
//osadzamy w odpowiednich panelach elementy
mainPanel.add(selectFile);
mainPanel.add(doIt);
mainPanel.add(close);
sizeGroup.add(size1);
sizeGroup.add(size2);
fSizePanel.add(size1);
fSizePanel.add(size2);
displayPanel.add(previewLabel);
convertionPanel.add(enableConvertion);
selectFile.addActionListener(this);
public void actionPerformed(ActionEvent e) {
int returnVal = fc.showOpenDialog(Converter.this);
if (returnVal == JFileChooser.APPROVE_OPTION)
File fileIn = fc.getSelectedFile();
JFrame frame1=new JFrame();
JOptionPane.showMessageDialog(frame1, fileIn.getName());
if(fileIn==null)
JFrame frame2 = new JFrame();
JOptionPane.showMessageDialog(frame2,"FileIN==NULL");
//############## PROBLEM IS HERE ###########################
try
Image img=ImageIO.read(fileIn); // HERE IS THE PROBLEM: img==NULL
// WHERAS fileIn!=NULL
}catch (IOException event){}
if (img==null)
JFrame frame2 = new JFrame();
JOptionPane.showMessageDialog(frame2,"img==NULL");
private static void createAndShowGUI() {
//Make sure we have nice window decorations.
JFrame.setDefaultLookAndFeelDecorated(true);
//Create a new instance of LunarPhases.
Converter conv = new Converter();
//Create and set up the window.
JFrame convFrame = new JFrame("Conversion JPG <-> PNG");
convFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
convFrame.setContentPane(conv.mainPanel);
Insets insets = convFrame.getInsets();
convFrame.setSize(600 + insets.left + insets.right,400+insets.top + insets.bottom);
convFrame.setVisible(true);
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}

Answer 1

//############## PROBLEM IS HERE ###########################
try {
Image img=ImageIO.read(fileIn); // HERE IS THE PROBLEM: img==NULL
// WHERAS fileIn!=NULL
} catch (IOException event){}
if (img==null) {
    JFrame frame2 = new JFrame();
    JOptionPane.showMessageDialog(frame2,"img==NULL");
}1. Please use [code] tags when posting code -- it makes the code more readable.
2. When posting code, post a minimal example program. You could have filtered
out all the extraneous GUI code, for example. Remember: the shorter the code, the
more likely it is a forum member will read it! Posting long runs of code only
hurts yourself.
3. All that being said, your problem is a simple oversight: notice that the
variable "img" in your try block is a local variable, not the field named "img"
than you test after the try block.
You should have written:
try {
    img=ImageIO.read(fileIn);
} catch (IOException event){
    e.printStackTrace();
}