txtfilefilter.java

源程序（包括最初的版本

package treeandbtreedemo;

/**
 * <p>Title: 文件过滤类</p>
 * <p>Description: 过滤出 “ *.txt ” 文件</p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 1.0
 */

import java.io.*;
import javax.swing.filechooser.FileFilter;

class TxtFileFilter extends FileFilter {
    String ext;

    public TxtFileFilter(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) {
            String extension = fileName.substring(index+1).toLowerCase();
            if (extension.equals(ext))
                return true;
        }
        return false;
    }

    public String getDescription(){
        if (ext.equals("txt"))
            return "TXT File (*.txt)";

        return "";
    }
}