java文件操作类——递归删除，显示子目录

package day01;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.ArrayList;
import java.util.List;

public class FileUtils {
    /**
     * 列出指定目录下（包括其子目录）的所有文件
     * 
     * @param dir
     * @throws IOException
     */
    public static void listDirectory(File dir) {
        if (!dir.exists()) {
            throw new IllegalArgumentException("目录：" + dir + "不存在");
        }
        if (!dir.isDirectory()) {
            throw new IllegalArgumentException(dir + "不是目录");
        }
        File[] subs = dir.listFiles();
        if (subs != null && subs.length > 0) {
            for (File sub : subs) {
                if (sub.isDirectory()) {
                    listDirectory(sub);
                } else {
                    System.out.println(sub);
                }
            }
        }
    }

    /**
     * 删除指定目录及其包含的所有内容
     * 
     * @param dir
     * @throws IOException
     */
    public static void deleteDirectory(File dir) throws IOException {
        if (!dir.exists()) {
            throw new IllegalArgumentException("目录：" + dir + "不存在");
        }
        if (!dir.isDirectory()) {
            throw new IllegalArgumentException(dir + "不是目录");
        }
        File[] subs = dir.listFiles();
        if (subs != null && subs.length > 0) {
            for (File sub : subs) {
                if (sub.isDirectory()) {
                    deleteDirectory(sub);
                } else {
                    System.out.println(sub);
                    if (!sub.delete()) {
                        throw new IOException("无法删除文件：" + sub);
                    }
                }
            }
        }
        System.out.println(dir);
        if (!dir.delete()) {
            throw new IOException("无法删除目录：" + dir);
        }
    }

    /**
     * 列出指定目录下指定扩展名的所有文件
     * 
     * @param dir
     * @param extensions
     * @param recursive
     * @return
     */
    public static List<File> listFile(File dir, final String[] extensions,
            boolean recursive) {
        if (!dir.exists()) {
            throw new IllegalArgumentException("目录：" + dir + "不存在");
        }
        if (!dir.isDirectory()) {
            throw new IllegalArgumentException(dir + "不是目录");
        }
        FileFilter ff = null;
        if (extensions == null || extensions.length == 0) {
            ff = new FileFilter() {
                @Override
                public boolean accept(File pathname) {
                    return true;
                }
            };
        } else {
            ff = new FileFilter() {
                @Override
                public boolean accept(File pathname) {
                    if (pathname.isDirectory())
                        return true;
                    String name = pathname.getName();
                    for (String ext : extensions) {
                        if (name.endsWith(ext)) {
                            return true;
                        }
                    }
                    return false;
                }
            };
        }
        return listFile(dir, ff, recursive);
    }

    public static List<File> listFile(File dir, final String filename,
            boolean recursive) {
        if (!dir.exists()) {
            throw new IllegalArgumentException("目录：" + dir + "不存在");
        }
        if (!dir.isDirectory()) {
            throw new IllegalArgumentException(dir + "不是目录");
        }
        FileFilter ff = null;
        if (filename == null || filename.length() == 0) {
            ff = new FileFilter() {
                @Override
                public boolean accept(File pathname) {
                    return true;
                }
            };
        } else {
            ff = new FileFilter() {
                @Override
                public boolean accept(File pathname) {
                    if (pathname.isDirectory())
                        return true;
                    String name = pathname.getName();
                    if (name.indexOf(filename) != -1)
                        return true;
                    else
                        return false;
                }
            };
        }
        return listFile(dir, ff, recursive);
    }

    private static List<File> listFile(File dir, FileFilter ff,
            boolean recursive) {
        List<File> list = new ArrayList<File>();
        File[] subs = dir.listFiles(ff);
        if (subs != null && subs.length > 0) {
            for (File sub : subs) {
                if (sub.isFile()) {
                    list.add(sub);
                } else if (recursive) {
                    list.addAll(listFile(sub, ff, true));
                }
            }
        }
        return list;
    }
    public static void copyFile(File srcFile, File destFile) throws IOException {
        if (!srcFile.exists()) {
            throw new IllegalArgumentException("文件：" + srcFile + "不存在");
        }
        if (!srcFile.isFile()) {
            throw new IllegalArgumentException(srcFile + "不是文件");
        }
        RandomAccessFile srcRaf = new RandomAccessFile(srcFile, "r");
        if (!destFile.exists()) {
            if (!destFile.createNewFile())
                throw new IOException("无法创建文件：" + destFile);
        }
        RandomAccessFile destRaf = new RandomAccessFile(destFile, "rw");
        byte[] buffer = new byte[8 * 1024];
        int len = -1;
        while ((len = srcRaf.read(buffer)) != -1) {
            destRaf.write(buffer, 0, len);
        }
        srcRaf.close();
        destRaf.close();
    }

    public static void copyDirectory(File srcDir, File destDir)
            throws IOException {
        if (!srcDir.exists()) {
            throw new IllegalArgumentException("文件：" + srcDir + "不存在");
        }
        if (!srcDir.isDirectory()) {
            throw new IllegalArgumentException(srcDir + "不是目录");
        }
        if (!destDir.exists()) {
            if (!destDir.mkdir())
                throw new IOException("无法创建目录：" + destDir);
        }
        File[] subs = srcDir.listFiles();
        if (subs != null && subs.length > 0) {
            for (File sub : subs) {
                if (sub.isFile()) {
                    copyFile(sub, new File(destDir, sub.getName()));
                } else if (sub.isDirectory()) {
                    copyDirectory(sub, new File(destDir, sub.getName()));
                }
            }
        }
    }
}