如何從目錄和子目錄復制具有某些擴展名的所有文件？

Question

我知道如何將文件從一個目錄復制到另一個目錄，我想幫助的是復制擴展名為.jpg或.doc的文件。

例如。

復制D:/Pictures/Holidays所有文件

掃描上述路徑中的所有文件夾，並將所有jpg傳輸到提供的目的地。

Answer 1

這可行，但是可以針對大文件增強文件'copy（File file，File outputFolder）'方法：

package net.bpfurtado.copyfiles;

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

public class CopyFilesFromType
{
    public static void main(String[] args)
    {
        new CopyFilesFromType().copy("jpg", "C:\\Users\\BrunoFurtado\\Pictures", "c:/temp/photos");
    }

    private FileTypeOrFolderFilter filter = null;

    private void copy(final String fileType, String fromPath, String outputPath)
    {
        filter = new FileTypeOrFolderFilter(fileType);
        File currentFolder = new File(fromPath);
        File outputFolder = new File(outputPath);
        scanFolder(fileType, currentFolder, outputFolder);
    }

    private void scanFolder(final String fileType, File currentFolder, File outputFolder)
    {
        System.out.println("Scanning folder [" + currentFolder + "]...");
        File[] files = currentFolder.listFiles(filter);
        for (File file : files) {
            if (file.isDirectory()) {
                scanFolder(fileType, file, outputFolder);
            } else {
                copy(file, outputFolder);
            }
        }
    }

    private void copy(File file, File outputFolder)
    {
        try {
            System.out.println("\tCopying [" + file + "] to folder [" + outputFolder + "]...");
            InputStream input = new FileInputStream(file);
            OutputStream out = new FileOutputStream(new File(outputFolder + File.separator + file.getName()));
            byte data[] = new byte[input.available()];
            input.read(data);
            out.write(data);
            out.flush();
            out.close();
            input.close();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    private final class FileTypeOrFolderFilter implements FileFilter
    {
        private final String fileType;

        private FileTypeOrFolderFilter(String fileType)
        {
            this.fileType = fileType;
        }

        public boolean accept(File pathname)
        {
            return pathname.getName().endsWith("." + fileType) || pathname.isDirectory();
        }
    }
}

Answer 2

使用以下文件沃克樹類來做到這一點

static class TreeCopier implements FileVisitor<Path> {

        private final Path source;
        private final Path target;
        private final boolean preserve;
        private String []fileTypes;

        TreeCopier(Path source, Path target, boolean preserve, String []types) {
            this.source = source;
            this.target = target;
            this.preserve = preserve;
            this.fileTypes = types;
        }

        @Override
        public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
            // before visiting entries in a directory we copy the directory
            // (okay if directory already exists).
            CopyOption[] options = (preserve)
                    ? new CopyOption[]{COPY_ATTRIBUTES} : new CopyOption[0];

            Path newdir = target.resolve(source.relativize(dir));
            try {
                Files.copy(dir, newdir, options);
            } catch (FileAlreadyExistsException x) {
                // ignore
            } catch (IOException x) {
                System.err.format("Unable to create: %s: %s%n", newdir, x);
                return SKIP_SUBTREE;
            }
            return CONTINUE;
        }

        @Override
        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
            String fileName = file.toFile().getName();
            boolean correctType = false;
            for(String t: fileTypes) {
                if(fileName.endsWith(t)){
                    correctType = true;
                    break;
                }
            }
            if(correctType)
                copyFile(file, target.resolve(source.relativize(file)), preserve);
            return CONTINUE;
        }

        @Override
        public FileVisitResult postVisitDirectory(Path dir, IOException exc) {
            // fix up modification time of directory when done
            if (exc == null && preserve) {
                Path newdir = target.resolve(source.relativize(dir));
                try {
                    FileTime time = Files.getLastModifiedTime(dir);
                    Files.setLastModifiedTime(newdir, time);
                } catch (IOException x) {
                    System.err.format("Unable to copy all attributes to: %s: %s%n", newdir, x);
                }
            }
            return CONTINUE;
        }

        @Override
        public FileVisitResult visitFileFailed(Path file, IOException exc) {
            if (exc instanceof FileSystemLoopException) {
                System.err.println("cycle detected: " + file);
            } else {
                System.err.format("Unable to copy: %s: %s%n", file, exc);
            }
            return CONTINUE;
        }


        static void copyFile(Path source, Path target, boolean preserve) {
            CopyOption[] options = (preserve)
                    ? new CopyOption[]{COPY_ATTRIBUTES, REPLACE_EXISTING}
                    : new CopyOption[]{REPLACE_EXISTING};
            if (Files.notExists(target)) {
                try {
                    Files.copy(source, target, options);
                } catch (IOException x) {
                    System.err.format("Unable to copy: %s: %s%n", source, x);
                }
            }
        }

    }

並使用以下兩行調用它

String []types = {".java", ".form"};
                TreeCopier tc = new TreeCopier(src.toPath(), dest.toPath(), false, types);
                Files.walkFileTree(src.toPath(), tc);

復制並傳遞.java和.form文件類型，因為String數組參數，src.toPath（）和dest.toPath（）是源路徑和目標路徑，false用來指定不保留以前的文件並在以下情況下覆蓋它們你想反向就是只考慮這些去除而不是用作

if(!correctType)

Answer 3

列出文件時使用FileFilter 。

在這種情況下，過濾器將選擇目錄和感興趣的任何文件類型。

---

這是一個獲取目錄結構中文件類型列表的快速示例（從另一個項目中砍掉了）。

import java.io.*;
import java.util.ArrayList;

class ListFiles {

    public static void populateFiles(File file, ArrayList<File> files, FileFilter filter) {
        File[] all = file.listFiles(filter);

        for (File f : all) {
            if (f.isDirectory()) {
                populateFiles(f,files,filter);
            } else {
                files.add(f);
            }
        }
    }

    public static void main(String[] args) throws Exception {
        String[] types = {
            "java",
            "class"
        };
        FileFilter filter = new FileTypesFilter(types);
        File f = new File("..");
        ArrayList<File> files = new ArrayList<File>();
        populateFiles(f, files, filter);

        for (File file : files) {
            System.out.println(file);
        }
    }
}

class FileTypesFilter implements FileFilter {

    String[] types;

    FileTypesFilter(String[] types) {
        this.types = types;
    }

    public boolean accept(File f) {
        if (f.isDirectory()) return true;
        for (String type : types) {
            if (f.getName().endsWith(type)) return true;
        }
        return false;
    }
}

Answer 4

看一下File類中的listFiles方法：

鏈接1

連結2

Answer 5

您可以嘗試以下代碼：

public class MyFiler implements FileNameFilter{

  bool accept(File file, String name){
     if(name.matches("*.jpg");
  }

}    


public void MassCopy(){
  ArrayList<File> filesToCopy = new ArrayList<File>();
  File sourceDirectory = new File("D:/Pictures/Holidays");
  String[] toCopy = sourceDirectory.list(new MyFilter());
  for(String file : toCopy){
    copyFileToDestination(file);
  }

 }