import java.util.comparator;
        import java.io.file;
        /**
        * created by intellij idea.<br>
        * <b>user</b>: leizhimin<br>
        * <b>date</b>: 2008-7-18 22:43:44<br>
        * <b>note</b>: 文件排序，按照先目录后文件方式排
        */
        public class filecomparator implements comparator<file> { 

            public int compare(file o1, file o2) {
                if (o1.isdirectory() && o2.isdirectory()) return o1.compareto(o2);
                else if(o1.isdirectory() && !o2.isdirectory()) return -1;
                else if(!o1.isdirectory() && o2.isdirectory()) return 1;
                else return o1.compareto(o2);
            }
        }

import java.io.file;
        import java.util.*;
        import java.sql.date;
        import java.text.dateformat;
        import java.text.simpledateformat;
        import java.text.numberformat;
        /**
        * created by intellij idea.<br>
        * <b>user</b>: leizhimin<br>
        * <b>date</b>: 2008-7-18 22:02:30<br>
        * <b>note</b>: 模拟dir测试的例程
        */ 



        public class testfile {
            public static dateformat df = new simpledateformat("yyyy-mm-dd hh:mm");
            int nl = 18;
            public static void main(string args[]) {
                test();
            }
            public static void test() {
                system.out.println("----------test()----------");
                file file = new file("f:\\soft_dev");
        //        file.isdirectory(); 
        //        system.out.println(file.pathseparator);
        //        system.out.println(file.pathseparatorchar);
        //        system.out.println(file.separator);
        //        system.out.println(file.separatorchar);
                filecomparator fc = new filecomparator();
                file[] lf = file.listfiles();
                arrays.sort(lf, fc);    //数组排序
                for (file f : lf) { 



                    string datastr = df.format(new date(f.lastmodified())); 
                    if (f.isdirectory()) {
                        system.out.print(datastr + "  <dir>       "); 

                    } else {
                        system.out.print(datastr + "  " + 工程
                            getformatstring(string.valueof
                            (numberformat.getinstance()
                                .format(f.length()))));
                    }
                    system.out.println("  " + f.getname());
                } 

            }
            //格式化函数
            public static string getformatstring(string s) {
                int nb = 12 - s.length();
                stringbuilder sb = new stringbuilder();
                if (nb > 0) {
                    for (int n = 1; n <= nb; n++) {
                        sb = sb.append(" ");
                    } 
                }
                return sb.append(s).tostring();
            }
        }