操作文件处理常用方法（Java实现）

1.通过递归算法查找指定文件
public class FileSearch {
    public static void main(String[] args) {
        FileFilter filter = new FileFilter() {
            public boolean accept(File pathname) {
                return pathname.getName().equals("aa.xml");
            }
        };
        List<File> list = search("./sjs/xml", filter);
        for (File file : list) {
            System.out.println(file.getName());
        }
    }
    public static List<File> search(String filePath, FileFilter filter) {
    return search(new File(filePath), filter);
}
// 递归算法遍历指定文件
public static List<File> search(File file, FileFilter filter) {
    List<File> result = new LinkedList<File>();
    if (!file.exists()) {
        return null;
    }
    if (file.isDirectory()) {
        File[] subs = file.listFiles();
        if (subs != null) {
            for (File sub : subs) {
                result.addAll(search(sub, filter));
            }
        }
    }
    if (filter.accept(file)) {
        result.add(file);
    }
    return result;
    }
}
2.通过递归算法删除指定文件
public class FileDelete {
//删除指定目录下以".txt"结尾的文件
    public static void main(String...filter) {
        deleteFile("./sjs/xml", new FileFilter(){
            public boolean accept(File pathname) {
                return pathname.getName().endsWith(".txt");
            }
        });
    }
    public static void deleteFile(String filePath,FileFilter filter) {
    if(filePath == null || "".equals(filePath)) {
        return ;
    }
    //如果过滤器为空，为了防止删去所有的文件，故不做删除操作
    if(filter == null ) {
        return ;
    }
    deleteFile(new File(filePath), filter) ;
}
private static void deleteFile(File file,FileFilter filter) {
    if(!file.exists()) {
    return ;
    }
    if(file.isDirectory()) {
        File[] subs = file.listFiles(filter) ;
        if(subs != null ) {
            for(File sub : subs ) {
                deleteFile(sub, filter) ;
            }
        }
    }
    if(filter.accept(file)) {
        file.delete() ;
    }
    }
}
3.文件切割器
public class FileSplit {
    public static void main(String...output) {
        long start = System.currentTimeMillis() ;
        split("C:\\fileparse\\nohup.out","C:\\logs",1024*1024*4L) ;
        System.out.println(System.currentTimeMillis() -     start) ;
    }
    public static void split(String source, String output, long capcity) {
        File sourceFile = new File(source);
        long length = sourceFile.length();
        if (length <= 0) {
            return;
        }
        if (capcity <= 0) {
            capcity = 1024 * 1024L;
        }
        long size = (length % capcity == 0) ? length /     capcity : length / capcity + 1;
        InputStream is = null;
        OutputStream out = null;
        try {
            is = new FileInputStream(sourceFile);
            byte[] once = new byte[(int) capcity];
            int readReally = 0;
            for (int start = (int) size; start > 0; start--){
            try {
                readReally = is.read(once);
                byte[] really = new byte[readReally];
                System.arraycopy(once, 0, really, 0, readReally);
                out = new FileOutputStream(new File(output, sourceFile.getName()+"-" + start), false);
                out.write(really);
                out.flush();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (out != null) {
                    try {
                        out.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
               }
            }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}