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);        
   } 
}