关于java:Java-IO系统一

package javaio;import java.io.File;import java.io.FilenameFilter;import java.util.Arrays;import java.util.regex.Pattern;public class DirList {    public static void main(String[] args) {        File path = new File(".");        String[] list;        if (args.length == 0) {            list=path.list();        }else            list= path.list(new DirFilter(args[0]));        Arrays.sort(list, String.CASE_INSENSITIVE_ORDER);        for (String dirItem : list) {            System.out.println(dirItem);        }    }}class DirFilter implements FilenameFilter {    private Pattern pattern;    public DirFilter(String regex) {        this.pattern = Pattern.compile(regex);    }    @Override    public boolean accept(File dir, String name) {        return pattern.matcher(name).matches();    }}