What is the best (easiest) way to create thumbnails?

Question

From (image) files selected via JFileChooser, what is the best way to create thumbnails so they can be immediately displayed?

Answer 1

package projects.web;
import javax.swing.*;
public class UploadApplet extends JApplet{
     public void displayGUI(){
          AppletGUI createGUI = new AppletGUI(getRootPane());
     public void init(){
          try{
               SwingUtilities.invokeAndWait(new Runnable(){
                    public void run(){
                         displayGUI();
          } catch (Exception e){
               e.printStackTrace();
} // end UploadApplet class
package projects.web;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.text.*;
import java.util.*;
import java.io.*;
public class AppletGUI{
     // JButtons
     JButton addButton = new JButton("Add");
     // JPanels
     JPanel containerPanel = new JPanel();
     JPanel optionsPanel = new JPanel();
     JPanel thumbnailPanel = new JPanel();
     // JScrollPane
     JScrollPane thumbnailScroll;
     public AppletGUI(JRootPane topContainer){
          // Add actionListener
          addButton.addActionListener(new ButtonHandler());
          // Set border layout
          containerPanel.setLayout(new BorderLayout());
          // Add buttons to target panels
          optionsPanel.add(addButton);
          // Set size and color of thumbnail panel
          thumbnailPanel.setPreferredSize(new Dimension (600,500));
          thumbnailPanel.setBackground(Color.white);
          thumbnailPanel.setBorder(new LineBorder(Color.black));
          // Add thumbnail panel to scrollpane
          thumbnailScroll = new JScrollPane(thumbnailPanel);
          // Set background color of scrollPane
          thumbnailScroll.setBackground(Color.white);
          // Add subpanels to containerPanel
          containerPanel.add(optionsPanel, BorderLayout.NORTH);
          containerPanel.add(thumbnailScroll, BorderLayout.CENTER);
          // Add containerPanel to rootPane's contentPane
          topContainer.getContentPane().add(containerPanel);
     } // end constructor
     class ButtonHandler implements ActionListener{
          public void actionPerformed(ActionEvent e){
               new FileBrowser();
          } // end actionPerformed method
     } // end inner class ActionHandler
} // end AppletGUI class
package projects.web;
import java.awt.*;
import java.io.*;
import javax.swing.*;
import javax.swing.filechooser.*;
import javax.imageio.*;
import java.util.*;
public class FileBrowser{
     JFileChooser fileChooser = new JFileChooser();
     int fileChooserOption;
     LinkedList<File> selectedFilesList = new LinkedList<File>();
     LinkedList<String> fileNames = new LinkedList<String>();
     public FileBrowser(){
          fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
          fileChooser.setMultiSelectionEnabled(true);
          fileChooserOption = fileChooser.showOpenDialog(null);
          if (fileChooserOption == JFileChooser.APPROVE_OPTION){
          for (File selectedFile : fileChooser.getSelectedFiles()){
                    selectedFilesList.add(selectedFile);
                    fileNames.add(selectedFile.getName());
          } // end enhanced for loop
          } // end if
     } // end constructor
} // end class FileBrowser