java之高效操作文件

代码:

 import java.io.IOException;
 import java.nio.file.FileVisitOption;
 import java.nio.file.FileVisitResult;
 import java.nio.file.FileVisitor;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.EnumSet;
 class DeleteDirectory implements FileVisitor {     

  boolean deleteFileByFile(Path file) throws IOException {
     return Files.deleteIfExists(file);
  } 

  @Override
  public FileVisitResult postVisitDirectory(Object dir, IOException exc)
                                                                   throws IOException { 

     if (exc == null) {
         System.out.println("Visited: " + (Path) dir);
         boolean success = deleteFileByFile((Path) dir); 

         if (success) {
              System.out.println("Deleted: " + (Path) dir);
         } else {
               System.out.println("Not deleted: " + (Path) dir);
         }
     } else {
         throw exc;
     }
     return FileVisitResult.CONTINUE;
  } 

  @Override
  public FileVisitResult preVisitDirectory(Object dir, BasicFileAttributes attrs)
                                                                   throws IOException {
    return FileVisitResult.CONTINUE;
  } 

  @Override
  public FileVisitResult visitFile(Object file, BasicFileAttributes attrs)
                                                                   throws IOException {
    boolean success = deleteFileByFile((Path) file); 

    if (success) {
         System.out.println("Deleted: " + (Path) file);
    } else {
         System.out.println("Not deleted: " + (Path) file);
    } 

    return FileVisitResult.CONTINUE;
  } 

  @Override
  public FileVisitResult visitFileFailed(Object file, IOException exc)
                                                                   throws IOException {
    //report an error if necessary 

    return FileVisitResult.CONTINUE;
  }
 } 

 class Main { 

  public static void main(String[] args) throws IOException { 

    Path directory = Paths.get("C:/rafaelnadal");
    DeleteDirectory walk = new DeleteDirectory();
    EnumSet opts = EnumSet.of(FileVisitOption.FOLLOW_LINKS); 

    Files.walkFileTree(directory, opts, Integer.MAX_VALUE, walk);
    }
 }