按照文件大小排序

public static void orderByLength(String fliePath) {
 List< File> files = Arrays.asList(new File(fliePath).listFiles());
 Collections.sort(files, new Comparator< File>() {
     public int compare(File f1, File f2) {
    long diff = f1.length() - f2.length();
    if (diff > 0)
      return 1;
    else if (diff == 0)
      return 0;
    else
      return -1;
     }
    public boolean equals(Object obj) {
    return true;
    }
   });
   for (File f : files) {
      if(f.isDirectory()) continue;
      System.out.println(f.getName()+":"+f.length());
   }
}

按照文件名称排序

public static void orderByName(String fliePath) {
  List files = Arrays.asList(new File(fliePath).listFiles());
  Collections.sort(files, new Comparator< File>() {
   @Override
   public int compare(File o1, File o2) {
    if (o1.isDirectory() && o2.isFile())
          return -1;
    if (o1.isFile() && o2.isDirectory())
          return 1;
    return o1.getName().compareTo(o2.getName());
   }
  });
   for (File f : files) {
     System.out.println(f.getName());
    }
  }

按日期排序

public static void orderByDate(String fliePath) {
   File file = new File(fliePath);
   File[] fs = file.listFiles();
   Arrays.sort(fs,new Comparator< File>(){
     public int compare(File f1, File f2) {
    long diff = f1.lastModified() - f2.lastModified();
    if (diff > 0)
      return 1;
    else if (diff == 0)
      return 0;
    else
      return -1;
     }
     public boolean equals(Object obj) {
    return true;
     }
        
     });
     for (int i = fs.length-1; i >-1; i--) {
    System.out.println(fs[i].getName());
    System.out.println(new Date(fs[i].lastModified()));
      }
  }