如何递归复制整个目录，包括Java中的父文件夹

Question

我目前正在处理从一个地方到另一个地方的文件夹。它工作正常，但它没有复制所有其余文件和文件夹所在的原始文件夹。这是我正在使用的代码：

public static void copyFolder(File src, File dest) throws IOException {
  if (src.isDirectory()) {
    //if directory not exists, create it
    if (!dest.exists()) {
      dest.mkdir();
    }
    //list all the directory contents
    String files[] = src.list();
    for (String file : files) {
      //construct the src and dest file structure
      File srcFile = new File(src, file);
      File destFile = new File(dest+"\\"+src.getName(), file);
      //recursive copy
      copyFolder(srcFile,destFile);
    }
  } else {
    //if file, then copy it
    //Use bytes stream to support all file types
    InputStream in = new FileInputStream(src);
    OutputStream out = new FileOutputStream(dest); 
    byte[] buffer = new byte[1024];
    int length;
    //copy the file content in bytes 
    while ((length = in.read(buffer)) > 0){
      out.write(buffer, 0, length);
    }
    in.close();
    out.close();
    System.out.println("File copied from " + src + " to " + dest);
  }
}

所以我有文件夹 src C:\test\mytest\..all folders..

我想复制到C:\test\myfiles

但我没有得到C:\test\myfiles\mytest\..all folders..，而是得到C:\test\myfiles\..all folders..

Answer 1

尝试改用Apache Commons IO 库中的copyDirectory(File srcDir, File destDir) 方法。

Answer 2

有一个tutorial for copying files using java.nio 带有一个递归副本example code on Oracle Docs。它适用于 java se 7+。它使用 might cause some issues on ntfs with junction points 的 Files.walkFileTree 方法。为避免使用 Files.walkFileTree，可能的解决方案如下所示：

public static void copyFileOrFolder(File source, File dest, CopyOption...  options) throws IOException {
    if (source.isDirectory())
        copyFolder(source, dest, options);
    else {
        ensureParentFolder(dest);
        copyFile(source, dest, options);
    }
}

private static void copyFolder(File source, File dest, CopyOption... options) throws IOException {
    if (!dest.exists())
        dest.mkdirs();
    File[] contents = source.listFiles();
    if (contents != null) {
        for (File f : contents) {
            File newFile = new File(dest.getAbsolutePath() + File.separator + f.getName());
            if (f.isDirectory())
                copyFolder(f, newFile, options);
            else
                copyFile(f, newFile, options);
        }
    }
}

private static void copyFile(File source, File dest, CopyOption... options) throws IOException {
    Files.copy(source.toPath(), dest.toPath(), options);
}

private static void ensureParentFolder(File file) {
    File parent = file.getParentFile();
    if (parent != null && !parent.exists())
        parent.mkdirs();
} 

Answer 3

你也可以试试Apache FileUtils复制目录

Answer 4

你应该试试apache commons FileUtils

Answer 5

使用 java.nio：

import java.io.IOException;
import java.nio.file.*;
import java.nio.file.attribute.BasicFileAttributes;

public static void copy(String sourceDir, String targetDir) throws IOException {

    abstract class MyFileVisitor implements FileVisitor<Path> {
        boolean isFirst = true;
        Path ptr;
    }

    MyFileVisitor copyVisitor = new MyFileVisitor() {

        @Override
        public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
            // Move ptr forward
            if (!isFirst) {
                // .. but not for the first time since ptr is already in there
                Path target = ptr.resolve(dir.getName(dir.getNameCount() - 1));
                ptr = target;
            }
            Files.copy(dir, ptr, StandardCopyOption.COPY_ATTRIBUTES);
            isFirst = false;
            return FileVisitResult.CONTINUE;
        }

        @Override
        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
            Path target = ptr.resolve(file.getFileName());
            Files.copy(file, target, StandardCopyOption.COPY_ATTRIBUTES);
            return FileVisitResult.CONTINUE;
        }

        @Override
        public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
            throw exc;
        }

        @Override
        public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
            Path target = ptr.getParent();
            // Move ptr backwards
            ptr = target;
            return FileVisitResult.CONTINUE;
        }
    };

    copyVisitor.ptr = Paths.get(targetDir);
    Files.walkFileTree(Paths.get(sourceDir), copyVisitor);
}

Answer 6

当然 spring 也涵盖了 FileSystemUtils.copyRecursively(File src, File dest)

Answer 7

此解决方案非常简单，但不是独立于平台的，因为命令是以纯文本形式提供给操作系统的。 （此示例适用于基于 Unix 的 shell，对于 Windows，命令看起来会有些不同 cp 称为 copy）。

String source = "/user/.../testDir";
String destination = "/Library/.../testDestination/testDir";
String command = "cp -r " + source + " " + destination;
Process p;
try {
    p = Runtime.getRuntime().exec(command);
    p.waitFor();
} catch (InterruptedException | IOException e) {
    // Error handling
}

如果要将对象复制到同名的子文件夹中，请将其添加到目标路径中，否则省略，则文件夹内容将直接复制到目标路径中。

编辑：不幸的是，这个解决方案不适用于网络驱动器。原因我不知道（但我承认我没有任何理由去挖掘）

Answer 8

主要问题是这样的：

  dest.mkdir();

只创建一个目录，不创建父目录，第一步后需要创建两个目录，所以将mkdir替换为mkdirs。 在那之后，我猜你会有重复的子目录，因为你的递归（像 C:\test\myfiles\mytest\dir1\dir1\subdir1\subdir1...），所以也尝试修复这些行：

    File destFile = new File(dest, src.getName());
    /**/
    OutputStream out = new FileOutputStream(new File(dest, src.getName())); 

Answer 9

此代码将文件夹从源复制到目标：

    public static void copyDirectory(String srcDir, String dstDir)
    {

        try {
            File src = new File(srcDir);
            String ds=new File(dstDir,src.getName()).toString();
            File dst = new File(ds);

            if (src.isDirectory()) {
                if (!dst.exists()) {
                    dst.mkdir();
                }

                String files[] = src.list();
                int filesLength = files.length;
                for (int i = 0; i < filesLength; i++) {
                    String src1 = (new File(src, files[i]).toString());
                    String dst1 = dst.toString();
                    copyDirectory(src1, dst1);

                }
            } else {
                fileWriter(src, dst);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
public static void fileWriter(File srcDir, File dstDir) throws IOException
{
        try {
            if (!srcDir.exists()) {
                System.out.println(srcDir + " doesnot exist");
                throw new IOException(srcDir + " doesnot exist");
            } else {
                InputStream in = new FileInputStream(srcDir);
                OutputStream out = new FileOutputStream(dstDir);
                // Transfer bytes from in to out
                byte[] buf = new byte[1024];
                int len;
                while ((len = in.read(buf)) > 0) {
                    out.write(buf, 0, len);
                }
                in.close();
                out.close();

            }
        } catch (Exception e) {

        }
    }