java nio: walkFileTree实现文件夹复制移动删除

package net.gdface.iadb;

import java.io.IOException;
import java.nio.file.CopyOption;
import java.nio.file.DirectoryNotEmptyException;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.StandardCopyOption;
import java.nio.file.attribute.BasicFileAttributes;

/**
 * 使用于NIO实现文件夹的复制/移动,删除<br>
 * 需要java 1.7以上版本支持
 * @author guyadong
 *
 */
public class NioFileUtil {
    /**
     * 复制文件夹
     * @param source
     * @param target
     * @param options
     * @throws IOException
     * @see {@link #operateDir(boolean, Path, Path, CopyOption...)}
     */
    public static void copyDir(Path source, Path target, CopyOption... options) throws IOException{
        operateDir(false, source, target, options);
    }
    /**
     * 移动文件夹
     * @param source
     * @param target
     * @param options
     * @throws IOException
     * @see {@link #operateDir(boolean, Path, Path, CopyOption...)}
     */
    public static void moveDir(Path source, Path target, CopyOption... options) throws IOException{
        operateDir(true, source, target, options);
    }
    /**
     * 复制/移动文件夹
     * @param move 操作标记，为true时移动文件夹,否则为复制
     * @param source 要复制/移动的源文件夹
     * @param target 源文件夹要复制/移动到的目标文件夹
     * @param options 文件复制选项 
     * @throws IOException
     * @see Files#move(Path, Path, CopyOption...)
     * @see Files#copy(Path, Path, CopyOption...)
     * @see Files#walkFileTree(Path, java.nio.file.FileVisitor)
     */
    public static void operateDir(boolean move,Path source, Path target, CopyOption... options) throws IOException{
        if(null==source||!Files.isDirectory(source))
            throw new IllegalArgumentException("source must be directory");
        Path dest = target.resolve(source.getFileName());
        // 如果相同则返回
        if(Files.exists(dest)&&Files.isSameFile(source, dest))return;
        // 目标文件夹不能是源文件夹的子文件夹
        // isSub方法实现参见另一篇博客 http://blog.csdn.net/10km/article/details/54425614
        if(isSub(source,dest))
            throw new IllegalArgumentException("dest must not  be sub directory of source");
        boolean clear=true;     
        for(CopyOption option:options)
            if(StandardCopyOption.REPLACE_EXISTING==option){
                clear=false;
                break;
            }
        // 如果指定了REPLACE_EXISTING选项则不清除目标文件夹
        if(clear)
            deleteIfExists(dest);
        Files.walkFileTree(source, 
                new SimpleFileVisitor<Path>() {

                    @Override
                    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
                        // 在目标文件夹中创建dir对应的子文件夹
                        Path subDir = 0==dir.compareTo(source)?dest:dest.resolve(dir.subpath(source.getNameCount(), dir.getNameCount()));
                        Files.createDirectories(subDir);
                        return FileVisitResult.CONTINUE;
                    }

                    @Override
                    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
                        if(move)
                            Files.move(file, dest.resolve(file.subpath(source.getNameCount(), file.getNameCount())),options);
                        else
                            Files.copy(file, dest.resolve(file.subpath(source.getNameCount(), file.getNameCount())),options);
                        return FileVisitResult.CONTINUE;
                    }

                    @Override
                    public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
                        // 移动操作时删除源文件夹
                        if(move)
                            Files.delete(dir);
                        return super.postVisitDirectory(dir, exc);
                    }
                });
    }

    /**
     * 强制删除文件/文件夹(含不为空的文件夹)<br>
     * @param dir
     * @throws IOException
     * @see Files#deleteIfExists(Path)
     * @see Files#walkFileTree(Path, java.nio.file.FileVisitor)
     */
    public static void deleteIfExists(Path dir) throws IOException {
        try {
            Files.deleteIfExists(dir);
        } catch (DirectoryNotEmptyException e) {
            Files.walkFileTree(dir, new SimpleFileVisitor<Path>() {
                @Override
                public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
                    Files.delete(file);
                    return FileVisitResult.CONTINUE;
                }

                @Override
                public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
                    Files.delete(dir);
                    return super.postVisitDirectory(dir, exc);
                }
            });
        }
    }

}

    public void testCopy() throws IOException{
        Path start = Paths.get("d:\\tmp\\storeroot\\origin");
        Path target = Paths.get("E:\\tmp\\storeroot");
        NioFileUtil.copyDir(start, target);
    }