深入浅出JavaSwing程序设计一书的源代码

				import java.awt.event.*;
				import java.io.File;
				import javax.swing.filechooser.FileFilter;
				
				class PicsFileFilter extends FileFilter
				{
				    String ext;
				    
				    public PicsFileFilter(String ext)
				    {
				        this.ext = ext;
				    }
				    
				    public boolean accept(File file)
				    {
				        if (file.isDirectory())
				            return true;
				        
				        String fileName = file.getName();
				        int index = fileName.lastIndexOf('.');
				
				        if (index > 0 && index < fileName.length()-1) {
				            //