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如何将文件从一个位置复制到另一个位置?

我想将文件从一个位置复制到Java中的另一个位置。做这个的最好方式是什么?


这是我到目前为止:

import Java.io.File;
import Java.io.FilenameFilter;
import Java.util.ArrayList;
import Java.util.List;
public class TestArrayList {
    public static void main(String[] args) {
        File f = new File(
            "D:\\CBSE_Demo\\Demo_original\\fscommand\\contentplayer\\config");
        List<String>temp=new ArrayList<String>();
        temp.add(0, "N33");
        temp.add(1, "N1417");
        temp.add(2, "N331");
        File[] matchingFiles = null;
        for(final String temp1: temp){
            matchingFiles = f.listFiles(new FilenameFilter() {
                public boolean accept(File dir, String name) {
                    return name.startsWith(temp1);
                }
            });
            System.out.println("size>>--"+matchingFiles.length);

        }
    }
}

这不会复制文件,执行此操作的最佳方法是什么?

53
vijayk

您可以使用 this (或任何变体):

Files.copy(src, dst, StandardCopyOption.REPLACE_EXISTING);

另外,我建议使用File.separator/而不是\\使其兼容多个操作系统,问题/答案可用 这里 。.

由于您不确定如何临时存储文件,请查看ArrayList

List<File> files = new ArrayList();
files.add(foundFile);

要将List文件移动到单个目录中:

List<File> files = ...;
String path = "C:/destination/";
for(File file : files) {
    Files.copy(file.toPath(),
        (new File(path + file.getName())).toPath(),
        StandardCopyOption.REPLACE_EXISTING);
}
94
Menno

使用流

private static void copyFileUsingStream(File source, File dest) throws IOException {
    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);
        }
    } finally {
        is.close();
        os.close();
    }
}

使用频道

private static void copyFileUsingChannel(File source, File dest) throws IOException {
    FileChannel sourceChannel = null;
    FileChannel destChannel = null;
    try {
        sourceChannel = new FileInputStream(source).getChannel();
        destChannel = new FileOutputStream(dest).getChannel();
        destChannel.transferFrom(sourceChannel, 0, sourceChannel.size());
       }finally{
           sourceChannel.close();
           destChannel.close();
       }
}

使用Apache Commons IO lib:

private static void copyFileUsingApacheCommonsIO(File source, File dest) throws IOException {
    FileUtils.copyFile(source, dest);
}

使用Java SE 7 Files类:

private static void copyFileUsingJava7Files(File source, File dest) throws IOException {
    Files.copy(source.toPath(), dest.toPath());
}

性能测试:

    File source = new File("/Users/pankaj/tmp/source.avi");
    File dest = new File("/Users/pankaj/tmp/dest.avi");


    //copy file conventional way using Stream
    long start = System.nanoTime();
    copyFileUsingStream(source, dest);
    System.out.println("Time taken by Stream Copy = "+(System.nanoTime()-start));

    //copy files using Java.nio FileChannel
    source = new File("/Users/pankaj/tmp/sourceChannel.avi");
    dest = new File("/Users/pankaj/tmp/destChannel.avi");
    start = System.nanoTime();
    copyFileUsingChannel(source, dest);
    System.out.println("Time taken by Channel Copy = "+(System.nanoTime()-start));

    //copy files using Apache commons io
    source = new File("/Users/pankaj/tmp/sourceApache.avi");
    dest = new File("/Users/pankaj/tmp/destApache.avi");
    start = System.nanoTime();
    copyFileUsingApacheCommonsIO(source, dest);
    System.out.println("Time taken by Apache Commons IO Copy = "+(System.nanoTime()-start));

    //using Java 7 Files class
    source = new File("/Users/pankaj/tmp/sourceJava7.avi");
    dest = new File("/Users/pankaj/tmp/destJava7.avi");
    start = System.nanoTime();
    copyFileUsingJava7Files(source, dest);
    System.out.println("Time taken by Java7 Files Copy = "+(System.nanoTime()-start));

结果:

/*
 * File copy:
 * Time taken by Stream Copy            = 44582575000
 * Time taken by Channel Copy           = 104138195000
 * Time taken by Apache Commons IO Copy = 108396714000
 * Time taken by Java7 Files Copy       = 89061578000
 */

链接:

63
Alexander Sidikov Pfeif

使用Java> = 7中的New Java File类。.

创建以下方法并导入必要的库。.

public static void copyFile( File from, File to ) throws IOException {
    Files.copy( from.toPath(), to.toPath() );
} 

在main中使用如下所示的创建方法:

File dirFrom = new File(fileFrom);
File dirTo = new File(fileTo);

try {
        copyFile(dirFrom, dirTo);
} catch (IOException ex) {
        Logger.getLogger(TestJava8.class.getName()).log(Level.SEVERE, null, ex);
}

注意: - fileFrom是要复制到新文件fileTo到另一个文件夹的文件。.

Credits - @Scott: 用Java复制文件的标准简洁方法?

6
Amimo Benja
  public static void copyFile(File oldLocation, File newLocation) throws IOException {
        if ( oldLocation.exists( )) {
            BufferedInputStream  reader = new BufferedInputStream( new FileInputStream(oldLocation) );
            BufferedOutputStream  writer = new BufferedOutputStream( new FileOutputStream(newLocation, false));
            try {
                byte[]  buff = new byte[8192];
                int numChars;
                while ( (numChars = reader.read(  buff, 0, buff.length ) ) != -1) {
                    writer.write( buff, 0, numChars );
                }
            } catch( IOException ex ) {
                throw new IOException("IOException when transferring " + oldLocation.getPath() + " to " + newLocation.getPath());
            } finally {
                try {
                    if ( reader != null ){                      
                        writer.close();
                        reader.close();
                    }
                } catch( IOException ex ){
                    Log.e(TAG, "Error closing files when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() ); 
                }
            }
        } else {
            throw new IOException("Old location does not exist when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() );
        }
    }  
5
Quamber Ali

Files.exists()

Files.createDirectory()

Files.copy()

覆盖现有文件:Files.move()

Files.delete()

Files.walkFileTree() 在此处输入链接描述

0
Shinwar ismail

将文件从一个位置复制到另一个位置意味着,需要将整个内容复制到另一个位置.Files.copy(Path source, Path target, CopyOption... options) throws IOException此方法需要源位置,即原始文件位置和目标位置,这是一个新目标相同类型文件的文件夹位置(原始) 。目标位置需要存在于我们的系统中,否则我们需要创建文件夹位置,然后在该文件夹位置我们需要创建一个与原始文件名相同的文件。然后使用复制功能我们可以轻松地从一个位置复制文件对其他人。.

 public static void main(String[] args) throws IOException {
                String destFolderPath = "D:/TestFile/abc";
                String fileName = "pqr.xlsx";
                String sourceFilePath= "D:/TestFile/xyz.xlsx";
                File f = new File(destFolderPath);
                if(f.mkdir()){
                    System.out.println("Directory created!!!!");
                }
                else {
                    System.out.println("Directory Exists!!!!");
                }
                f= new File(destFolderPath,fileName);
                if(f.createNewFile())   {

                    System.out.println("File Created!!!!");
                }   else {
                    System.out.println("File exists!!!!");
                }

                Files.copy(Paths.get(sourceFilePath), Paths.get(destFolderPath, fileName),REPLACE_EXISTING);
                System.out.println("Copy done!!!!!!!!!!!!!!");


            }
0
S.Sarkar