使用Java将文件从一个目录复制到另一个目录

我想使用Java将文件从一个目录复制到另一个目录（子目录）。我有一个包含文本文件的目录dir。我遍历dir中的前20个文件，并想将它们复制到dir目录中的另一个目录中，该目录是我在迭代之前创建的。在代码中，我想将review（代表ith文本文件或审阅）复制到trainingDir。我怎样才能做到这一点？似乎没有这样的功能（或者我找不到）。谢谢。

boolean success = false;
File[] reviews = dir.listFiles();
String trainingDir = dir.getAbsolutePath() + "/trainingData";
File trDir = new File(trainingDir);
success = trDir.mkdir();
for(int i = 1; i <= 20; i++) {
    File review = reviews[i];

}

目前，这应该可以解决您的问题

File source = new File("H:\\work-temp\\file");
File dest = new File("H:\\work-temp\\file2");
try {
    FileUtils.copyDirectory(source, dest);
} catch (IOException e) {
    e.printStackTrace();
}

FileUtilsapache commons-io上的课程库，因为1.2版本。

使用第三方工具代替自己编写所有实用程序似乎是一个更好的主意。它可以节省时间和其他宝贵资源。

标准API中还没有文件复制方法（尚未）。您的选择是：

• 自己编写，使用FileInputStream，FileOutputStream和缓冲区将字节从一个字节复制到另一个字节-更好的是，使用FileChannel.transferTo（）
• 用户Apache Commons' FileUtils
• 在Java 7中等待NIO2

在Java 7中，是在Java中复制文件的标准方法：

Files.copy。

它与O / S本地I / O集成以实现高性能。

看到我的A on Standard简洁方法可以用Java复制文件吗？有关用法的完整说明。

下面来自Java Tips的示例非常简单。从那以后，我切换到Groovy进行文件系统的操作-更轻松，更优雅。但是这里是我过去使用的Java技巧。它缺少使它变得万无一失所需的强大的异常处理。

 public void copyDirectory(File sourceLocation , File targetLocation)
    throws IOException {

        if (sourceLocation.isDirectory()) {
            if (!targetLocation.exists()) {
                targetLocation.mkdir();
            }

            String[] children = sourceLocation.list();
            for (int i=0; i<children.length; i++) {
                copyDirectory(new File(sourceLocation, children[i]),
                        new File(targetLocation, children[i]));
            }
        } else {

            InputStream in = new FileInputStream(sourceLocation);
            OutputStream out = new FileOutputStream(targetLocation);

            // Copy the bits from instream to outstream
            byte[] buf = new byte[1024];
            int len;
            while ((len = in.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
            in.close();
            out.close();
        }
    }

如果您要复制文件而不移动它，则可以这样编写代码。

private static void copyFile(File sourceFile, File destFile)
        throws IOException {
    if (!sourceFile.exists()) {
        return;
    }
    if (!destFile.exists()) {
        destFile.createNewFile();
    }
    FileChannel source = null;
    FileChannel destination = null;
    source = new FileInputStream(sourceFile).getChannel();
    destination = new FileOutputStream(destFile).getChannel();
    if (destination != null && source != null) {
        destination.transferFrom(source, 0, source.size());
    }
    if (source != null) {
        source.close();
    }
    if (destination != null) {
        destination.close();
    }

}

Spring Framework具有许多类似的util类，例如Apache Commons Lang。所以有org.springframework.util.FileSystemUtils

File src = new File("/home/user/src");
File dest = new File("/home/user/dest");
FileSystemUtils.copyRecursively(src, dest);

apache commons Fileutils很方便。您可以进行以下活动。

1. 将文件从一个目录复制到另一目录。

   用 copyFileToDirectory(File srcFile, File destDir)

2. 将目录从一个目录复制到另一目录。

   用 copyDirectory(File srcDir, File destDir)

3. 将一个文件的内容复制到另一个

   用 static void copyFile(File srcFile, File destFile)

File sourceFile = new File("C:\\Users\\Demo\\Downloads\\employee\\"+img);
File destinationFile = new File("\\images\\" + sourceFile.getName());

FileInputStream fileInputStream = new FileInputStream(sourceFile);
FileOutputStream fileOutputStream = new FileOutputStream(
                destinationFile);

int bufferSize;
byte[] bufffer = new byte[512];
while ((bufferSize = fileInputStream.read(bufffer)) > 0) {
    fileOutputStream.write(bufffer, 0, bufferSize);
}
fileInputStream.close();
fileOutputStream.close();

import static java.nio.file.StandardCopyOption.*;
...
Files.copy(source, target, REPLACE_EXISTING);

资料来源：https : //docs.oracle.com/javase/tutorial/essential/io/copy.html

Apache commons FileUtils将很方便，如果您只想将文件从源目录移动到目标目录，而不是复制整个目录，则可以执行以下操作：

for (File srcFile: srcDir.listFiles()) {
    if (srcFile.isDirectory()) {
        FileUtils.copyDirectoryToDirectory(srcFile, dstDir);
    } else {
        FileUtils.copyFileToDirectory(srcFile, dstDir);
    }
}

如果要跳过目录，可以执行以下操作：

for (File srcFile: srcDir.listFiles()) {
    if (!srcFile.isDirectory()) {
        FileUtils.copyFileToDirectory(srcFile, dstDir);
    }
}

您似乎正在寻找简单的解决方案（一件好事）。我建议使用Apache Common的FileUtils.copyDirectory：

将整个目录复制到保存文件日期的新位置。

此方法将指定的目录及其所有子目录和文件复制到指定的目的地。目标是目录的新位置和名称。

如果目标目录不存在，则会创建该目录。如果目标目录确实存在，则此方法将源与目标合并，并且源优先。

您的代码可能会像这样漂亮而简单：

File trgDir = new File("/tmp/myTarget/");
File srcDir = new File("/tmp/mySource/");

FileUtils.copyDirectory(srcDir, trgDir);

受到莫希特（Mohit）在此主题中的回答的启发。仅适用于Java 8。

以下内容可用于将所有内容从一个文件夹递归复制到另一个文件夹：

public static void main(String[] args) throws IOException {
    Path source = Paths.get("/path/to/source/dir");
    Path destination = Paths.get("/path/to/dest/dir");

    List<Path> sources = Files.walk(source).collect(toList());
    List<Path> destinations = sources.stream()
            .map(source::relativize)
            .map(destination::resolve)
            .collect(toList());

    for (int i = 0; i < sources.size(); i++) {
        Files.copy(sources.get(i), destinations.get(i));
    }
}

流式FTW。

更新于2019-06-10：重要说明-关闭由Files.walk调用获取的流（例如，使用try-with-resource）。感谢@jannis的观点。

以下是Brian修改后的代码，该文件将文件从源位置复制到目标位置。

public class CopyFiles {
 public static void copyFiles(File sourceLocation , File targetLocation)
    throws IOException {

        if (sourceLocation.isDirectory()) {
            if (!targetLocation.exists()) {
                targetLocation.mkdir();
            }
            File[] files = sourceLocation.listFiles();
            for(File file:files){
                InputStream in = new FileInputStream(file);
                OutputStream out = new FileOutputStream(targetLocation+"/"+file.getName());

                // Copy the bits from input stream to output stream
                byte[] buf = new byte[1024];
                int len;
                while ((len = in.read(buf)) > 0) {
                    out.write(buf, 0, len);
                }
                in.close();
                out.close();
            }            
        }
    }

Java 8

Path sourcepath = Paths.get("C:\\data\\temp\\mydir");
        Path destinationepath = Paths.get("C:\\data\\temp\\destinationDir");        
        Files.walk(sourcepath)
             .forEach(source -> copy(source, destinationepath.resolve(sourcepath.relativize(source)))); 

复制方式

static void copy(Path source, Path dest) {
        try {
            Files.copy(source, dest, StandardCopyOption.REPLACE_EXISTING);
        } catch (Exception e) {
            throw new RuntimeException(e.getMessage(), e);
        }
    }

您可以解决将源文件复制到新文件并删除原始文件的问题。

public class MoveFileExample {

 public static void main(String[] args) {   

    InputStream inStream = null;
    OutputStream outStream = null;

    try {

        File afile = new File("C:\\folderA\\Afile.txt");
        File bfile = new File("C:\\folderB\\Afile.txt");

        inStream = new FileInputStream(afile);
        outStream = new FileOutputStream(bfile);

        byte[] buffer = new byte[1024];

        int length;
        //copy the file content in bytes 
        while ((length = inStream.read(buffer)) > 0) {
            outStream.write(buffer, 0, length);
        }

        inStream.close();
        outStream.close();

        //delete the original file
        afile.delete();

        System.out.println("File is copied successful!");

    } catch(IOException e) {
        e.printStackTrace();
    }
 }
}

用

org.apache.commons.io.FileUtils

好方便

File dir = new File("D:\\mital\\filestore");
File[] files = dir.listFiles(new File_Filter("*"+ strLine + "*.txt"));
for (File file : files){    
    System.out.println(file.getName());

    try {
        String sourceFile=dir+"\\"+file.getName();
        String destinationFile="D:\\mital\\storefile\\"+file.getName();
        FileInputStream fileInputStream = new FileInputStream(sourceFile);
        FileOutputStream fileOutputStream = new FileOutputStream(
                        destinationFile);
        int bufferSize;
        byte[] bufffer = new byte[512];
        while ((bufferSize = fileInputStream.read(bufffer)) > 0) {
            fileOutputStream.write(bufffer, 0, bufferSize);
        }
        fileInputStream.close();
        fileOutputStream.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

NIO类使这一过程变得非常简单。

http://www.javalobby.org/java/forums/t17036.html

我使用以下代码将上传CommonMultipartFile的文件传输到文件夹，然后将该文件复制到webapps（即Web项目文件夹）中的目标文件夹，

    String resourcepath = "C:/resources/images/" + commonsMultipartFile.getOriginalFilename();

    File file = new File(resourcepath);
    commonsMultipartFile.transferTo(file);

    //Copy File to a Destination folder
    File destinationDir = new File("C:/Tomcat/webapps/myProject/resources/images/");
    FileUtils.copyFileToDirectory(file, destinationDir);

将文件从一个目录复制到另一目录...

FileChannel source=new FileInputStream(new File("source file path")).getChannel();
FileChannel desti=new FileOutputStream(new File("destination file path")).getChannel();
desti.transferFrom(source, 0, source.size());
source.close();
desti.close();

这只是一个Java代码，用于将数据从一个文件夹复制到另一个文件夹，您只需要提供源和目标的输入即可。

import java.io.*;

public class CopyData {
static String source;
static String des;

static void dr(File fl,boolean first) throws IOException
{
    if(fl.isDirectory())
    {
        createDir(fl.getPath(),first);
        File flist[]=fl.listFiles();
        for(int i=0;i<flist.length;i++)
        {

            if(flist[i].isDirectory())
            {
                dr(flist[i],false);
            }

            else
            {

                copyData(flist[i].getPath());
            }
        }
    }

    else
    {
        copyData(fl.getPath());
    }
}

private static void copyData(String name) throws IOException {

        int i;
        String str=des;
        for(i=source.length();i<name.length();i++)
        {
            str=str+name.charAt(i);
        }
        System.out.println(str);
        FileInputStream fis=new FileInputStream(name);
        FileOutputStream fos=new FileOutputStream(str);
        byte[] buffer = new byte[1024];
        int noOfBytes = 0;
         while ((noOfBytes = fis.read(buffer)) != -1) {
             fos.write(buffer, 0, noOfBytes);
         }


}

private static void createDir(String name, boolean first) {

    int i;

    if(first==true)
    {
        for(i=name.length()-1;i>0;i--)
        {
            if(name.charAt(i)==92)
            {
                break;
            }
        }

        for(;i<name.length();i++)
        {
            des=des+name.charAt(i);
        }
    }
    else
    {
        String str=des;
        for(i=source.length();i<name.length();i++)
        {
            str=str+name.charAt(i);
        }
        (new File(str)).mkdirs();
    }

}

public static void main(String args[]) throws IOException
{
    BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
    System.out.println("program to copy data from source to destination \n");
    System.out.print("enter source path : ");
    source=br.readLine();
    System.out.print("enter destination path : ");
    des=br.readLine();
    long startTime = System.currentTimeMillis();
    dr(new File(source),true);
    long endTime   = System.currentTimeMillis();
    long time=endTime-startTime;
    System.out.println("\n\n Time taken = "+time+" mili sec");
}

}

这是您想要的工作代码。请告诉我是否有帮助

您可以使用以下代码将文件从一个目录复制到另一个目录

// parent folders of dest must exist before calling this function
public static void copyTo( File src, File dest ) throws IOException {
     // recursively copy all the files of src folder if src is a directory
     if( src.isDirectory() ) {
         // creating parent folders where source files is to be copied
         dest.mkdirs();
         for( File sourceChild : src.listFiles() ) {
             File destChild = new File( dest, sourceChild.getName() );
             copyTo( sourceChild, destChild );
         }
     } 
     // copy the source file
     else {
         InputStream in = new FileInputStream( src );
         OutputStream out = new FileOutputStream( dest );
         writeThrough( in, out );
         in.close();
         out.close();
     }
 }

    File file = fileChooser.getSelectedFile();
    String selected = fc.getSelectedFile().getAbsolutePath();
     File srcDir = new File(selected);
     FileInputStream fii;
     FileOutputStream fio;
    try {
         fii = new FileInputStream(srcDir);
         fio = new FileOutputStream("C:\\LOvE.txt");
         byte [] b=new byte[1024];
         int i=0;
        try {
            while ((fii.read(b)) > 0)
            {

              System.out.println(b);
              fio.write(b);
            }
            fii.close();
            fio.close();

以下代码将文件从一个目录复制到另一个目录

File destFile = new File(targetDir.getAbsolutePath() + File.separator
    + file.getName());
try {
  showMessage("Copying " + file.getName());
  in = new BufferedInputStream(new FileInputStream(file));
  out = new BufferedOutputStream(new FileOutputStream(destFile));
  int n;
  while ((n = in.read()) != -1) {
    out.write(n);
  }
  showMessage("Copied " + file.getName());
} catch (Exception e) {
  showMessage("Cannot copy file " + file.getAbsolutePath());
} finally {
  if (in != null)
    try {
      in.close();
    } catch (Exception e) {
    }
  if (out != null)
    try {
      out.close();
    } catch (Exception e) {
    }
}

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class CopyFiles {
    private File targetFolder;
    private int noOfFiles;
    public void copyDirectory(File sourceLocation, String destLocation)
            throws IOException {
        targetFolder = new File(destLocation);
        if (sourceLocation.isDirectory()) {
            if (!targetFolder.exists()) {
                targetFolder.mkdir();
            }

            String[] children = sourceLocation.list();
            for (int i = 0; i < children.length; i++) {
                copyDirectory(new File(sourceLocation, children[i]),
                        destLocation);

            }
        } else {

            InputStream in = new FileInputStream(sourceLocation);
            OutputStream out = new FileOutputStream(targetFolder + "\\"+ sourceLocation.getName(), true);
            System.out.println("Destination Path ::"+targetFolder + "\\"+ sourceLocation.getName());            
            // Copy the bits from instream to outstream
            byte[] buf = new byte[1024];
            int len;
            while ((len = in.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
            in.close();
            out.close();
            noOfFiles++;
        }
    }

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

        File srcFolder = new File("C:\\sourceLocation\\");
        String destFolder = new String("C:\\targetLocation\\");
        CopyFiles cf = new CopyFiles();
        cf.copyDirectory(srcFolder, destFolder);
        System.out.println("No Of Files got Retrieved from Source ::"+cf.noOfFiles);
        System.out.println("Successfully Retrieved");
    }
}

Java 7甚至没有那么复杂，也不需要导入：

该renameTo( )方法更改文件名：

public boolean renameTo( File destination)

例如，要将src.txt当前工作目录中的文件名更改为dst.txt，您可以编写：

File src = new File(" src.txt"); File dst = new File(" dst.txt"); src.renameTo( dst); 

而已。

参考：

Harold，Elliotte Rusty（2006-05-16）。Java I / O（第393页）。O'Reilly Media。Kindle版。

您可以使用以下代码将文件从一个目录复制到另一个目录

public static void copyFile(File sourceFile, File destFile) throws IOException {
        InputStream in = null;
        OutputStream out = null;
        try {
            in = new FileInputStream(sourceFile);
            out = new FileOutputStream(destFile);
            byte[] buffer = new byte[1024];
            int length;
            while ((length = in.read(buffer)) > 0) {
                out.write(buffer, 0, length);
            }
        } catch(Exception e){
            e.printStackTrace();
        }
        finally {
            in.close();
            out.close();
        }
    }

如果我对递归函数有所帮助，则可以这样做。它将源目录中的所有文件复制到destinationDirectory。

例：

rfunction("D:/MyDirectory", "D:/MyDirectoryNew", "D:/MyDirectory");

public static void rfunction(String sourcePath, String destinationPath, String currentPath) {
    File file = new File(currentPath);
    FileInputStream fi = null;
    FileOutputStream fo = null;

    if (file.isDirectory()) {
        String[] fileFolderNamesArray = file.list();
        File folderDes = new File(destinationPath);
        if (!folderDes.exists()) {
            folderDes.mkdirs();
        }

        for (String fileFolderName : fileFolderNamesArray) {
            rfunction(sourcePath, destinationPath + "/" + fileFolderName, currentPath + "/" + fileFolderName);
        }
    } else {
        try {
            File destinationFile = new File(destinationPath);

            fi = new FileInputStream(file);
            fo = new FileOutputStream(destinationPath);
            byte[] buffer = new byte[1024];
            int ind = 0;
            while ((ind = fi.read(buffer))>0) {
                fo.write(buffer, 0, ind);
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        finally {
            if (null != fi) {
                try {
                    fi.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (null != fo) {
                try {
                    fo.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

如果您不想使用外部库，而要使用java.io而不是java.nio类，则可以使用以下简洁方法来复制文件夹及其所有内容：

/**
 * Copies a folder and all its content to another folder. Do not include file separator at the end path of the folder destination.
 * @param folderToCopy The folder and it's content that will be copied
 * @param folderDestination The folder destination
 */
public static void copyFolder(File folderToCopy, File folderDestination) {
    if(!folderDestination.isDirectory() || !folderToCopy.isDirectory())
        throw new IllegalArgumentException("The folderToCopy and folderDestination must be directories");

    folderDestination.mkdirs();

    for(File fileToCopy : folderToCopy.listFiles()) {
        File copiedFile = new File(folderDestination + File.separator + fileToCopy.getName());

        try (FileInputStream fis = new FileInputStream(fileToCopy);
             FileOutputStream fos = new FileOutputStream(copiedFile)) {

            int read;
            byte[] buffer = new byte[512];

            while ((read = fis.read(buffer)) != -1) {
                fos.write(buffer, 0, read);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }
}

据我所知，最好的方法如下：

    public static void main(String[] args) {

    String sourceFolder = "E:\\Source";
    String targetFolder = "E:\\Target";
    File sFile = new File(sourceFolder);
    File[] sourceFiles = sFile.listFiles();
    for (File fSource : sourceFiles) {
        File fTarget = new File(new File(targetFolder), fSource.getName());
        copyFileUsingStream(fSource, fTarget);
        deleteFiles(fSource);
    }
}

    private static void deleteFiles(File fSource) {
        if(fSource.exists()) {
            try {
                FileUtils.forceDelete(fSource);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    private static void copyFileUsingStream(File source, File dest) {
        InputStream is = null;
        OutputStream os = null;
        try {
            is = new FileInputStream(source);
            os = new FileOutputStream(dest);
            byte[] buffer = new byte[1024];
            int length;
            while ((length = is.read(buffer)) > 0) {
                os.write(buffer, 0, length);
            }
        } catch (Exception ex) {
            System.out.println("Unable to copy file:" + ex.getMessage());
        } finally {
            try {
                is.close();
                os.close();
            } catch (Exception ex) {
            }
        }
    }