java 按文件名排序

 public class FileUtil {
     //for test
     public static void main(String []args) {
        File dirFile = new File("c://");
        
        File [] sortedFiles = listSortedFiles(dirFile);
     }
     //list sorted files
     public static File[] listSortedFiles(File dirFile) {
     assert dirFile.isDirectory();
        File[] files = dirFile.listFiles();
        
         FileWrapper [] fileWrappers = new FileWrapper[files.length];
         for (int i=0; i<files.length; i++) {
             fileWrappers[i] = new FileWrapper(files[i]);
         }
        
         Arrays.sort(fileWrappers);
        
        File []sortedFiles = new File[files.length];
         for (int i=0; i<files.length; i++) {
             sortedFiles[i] = fileWrappers[i].getFile();
         }
        
         return sortedFiles;
     }
}
class FileWrapper implements Comparable {
     /** File */
     private File file;
    
     public FileWrapper(File file) {
         this.file = file;
     }
    
     public int compareTo(Object obj) {
         assert obj instanceof FileWrapper;
        
         FileWrapper castObj = (FileWrapper)obj;
                
         if (this.file.getName().compareTo(castObj.getFile().getName()) > 0) {
             return 1;
         } else if (this.file.getName().compareTo(castObj.getFile().getName()) < 0) {
             return -1;
         } else {
             return 0;
         }
     }
    
     public File getFile() {
         return this.file;
     }
}