在java中怎么设置文件夹的属性

Question

以下是类File的原文件！
文件夹的操作和文件应该是一样的！
有些属性只能设置，而不能去掉！
象只能设置setReadOnly()，而不能去掉！
// Source File Name:   File.javapackage java.io;import java.net.MalformedURLException;
import java.net.URL;
import java.security.AccessControlException;
import java.security.AccessController;
import java.util.ArrayList;
import java.util.Random;
import sun.security.action.GetPropertyAction;// Referenced classes of package java.io:
//            Serializable, IOException, FileSystem, FilenameFilter, 
//            FileFilter, ObjectOutputStream, ObjectInputStreampublic class File
    implements Serializable, Comparable
{    int getPrefixLength()
    {
        return prefixLength;
    }    private File(String s, int i)
    {
        path = s;
        prefixLength = i;
    }    public File(String s)
    {
        if(s == null)
        {
            throw new NullPointerException();
        } else
        {
            path = fs.normalize(s);
            prefixLength = fs.prefixLength(path);
            return;
        }
    }    public File(String s, String s1)
    {
        if(s1 == null)
            throw new NullPointerException();
        if(s != null)
        {
            if(s.equals(""))
                path = fs.resolve(fs.getDefaultParent(), fs.normalize(s1));
            else
                path = fs.resolve(fs.normalize(s), fs.normalize(s1));
        } else
        {
            path = fs.normalize(s1);
        }
        prefixLength = fs.prefixLength(path);
    }    public File(File file, String s)
    {
        if(s == null)
            throw new NullPointerException();
        if(file != null)
        {
            if(file.path.equals(""))
                path = fs.resolve(fs.getDefaultParent(), fs.normalize(s));
            else
                path = fs.resolve(file.path, fs.normalize(s));
        } else
        {
            path = fs.normalize(s);
        }
        prefixLength = fs.prefixLength(path);
    }    public String getName()
    {
        int i = path.lastIndexOf(separatorChar);
        if(i < prefixLength)
            return path.substring(prefixLength);
        else
            return path.substring(i + 1);
    }    public String getParent()
    {
        int i = path.lastIndexOf(separatorChar);
        if(i < prefixLength)
        {
            if(prefixLength > 0 && path.length() > prefixLength)
                return path.substring(0, prefixLength);
            else
                return null;
        } else
        {
            return path.substring(0, i);
        }
    }

Answer 1

public File getParentFile()
    {
        String s = getParent();
        if(s == null)
            return null;
        else
            return new File(s, prefixLength);
    }    public String getPath()
    {
        return path;
    }    public boolean isAbsolute()
    {
        return fs.isAbsolute(this);
    }    public String getAbsolutePath()
    {
        return fs.resolve(this);
    }    public File getAbsoluteFile()
    {
        return new File(getAbsolutePath());
    }    public String getCanonicalPath()
        throws IOException
    {
        return fs.canonicalize(fs.resolve(this));
    }    public File getCanonicalFile()
        throws IOException
    {
        return new File(getCanonicalPath());
    }    public URL toURL()
        throws MalformedURLException
    {
        String s = getAbsolutePath();
        if(separatorChar != '/')
            s = s.replace(separatorChar, '/');
        if(!s.startsWith("/"))
            s = "/" + s;
        if(!s.endsWith("/") && isDirectory())
            s = s + "/";
        return new URL("file", "", s);
    }    public boolean canRead()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkRead(path);
        return fs.checkAccess(this, false);
    }    public boolean canWrite()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkWrite(path);
        return fs.checkAccess(this, true);
    }    public boolean exists()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkRead(path);
        return (fs.getBooleanAttributes(this) & 0x1) != 0;
    }    public boolean isDirectory()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkRead(path);
        return (fs.getBooleanAttributes(this) & 0x4) != 0;
    }    public boolean isFile()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkRead(path);
        return (fs.getBooleanAttributes(this) & 0x2) != 0;
    }    public boolean isHidden()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkRead(path);
        return (fs.getBooleanAttributes(this) & 0x8) != 0;
    }    public long lastModified()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkRead(path);
        return fs.getLastModifiedTime(this);
    }    public long length()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkRead(path);
        return fs.getLength(this);
    }    public boolean createNewFile()
        throws IOException
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkWrite(path);
        return fs.createFileExclusively(path);
    }    public boolean delete()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkDelete(path);
        return fs.delete(this);
    }    public void deleteOnExit()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkDelete(path);
        fs.deleteOnExit(this);
    }    public String[] list()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkRead(path);
        return fs.list(this);
    }    public String[] list(FilenameFilter filenamefilter)
    {
        String as[] = list();
        if(as == null || filenamefilter == null)
            return as;
        ArrayList arraylist = new ArrayList();
        for(int i = 0; i < as.length; i++)
            if(filenamefilter.accept(this, as[i]))
                arraylist.add(as[i]);        return (String[])arraylist.toArray(new String[0]);
    }    public File[] listFiles()
    {
        String as[] = list();
        if(as == null)
            return null;
        int i = as.length;
        File afile[] = new File[i];
        for(int j = 0; j < i; j++)
            afile[j] = new File(path, as[j]);        return afile;
    }    public File[] listFiles(FilenameFilter filenamefilter)
    {
        String as[] = list();
        if(as == null)
            return null;
        ArrayList arraylist = new ArrayList();
        for(int i = 0; i < as.length; i++)
            if(filenamefilter == null || filenamefilter.accept(this, as[i]))
                arraylist.add(new File(path, as[i]));        return (File[])arraylist.toArray(new File[0]);
    }    public File[] listFiles(FileFilter filefilter)
    {
        String as[] = list();
        if(as == null)
            return null;
        ArrayList arraylist = new ArrayList();
        for(int i = 0; i < as.length; i++)
        {
            File file = new File(path, as[i]);
            if(filefilter == null || filefilter.accept(file))
                arraylist.add(file);
        }        return (File[])arraylist.toArray(new File[0]);
    }

Answer 2

public boolean mkdir()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkWrite(path);
        return fs.createDirectory(this);
    }    public boolean mkdirs()
    {
        if(exists())
            return false;
        if(mkdir())
        {
            return true;
        } else
        {
            String s = getParent();
            return s != null && (new File(s)).mkdirs() && mkdir();
        }
    }    public boolean renameTo(File file)
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
        {
            securitymanager.checkWrite(path);
            securitymanager.checkWrite(file.path);
        }
        return fs.rename(this, file);
    }    public boolean setLastModified(long l)
    {
        if(l < 0L)
            throw new IllegalArgumentException("Negative time");
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkWrite(path);
        return fs.setLastModifiedTime(this, l);
    }    public boolean setReadOnly()
    {
        SecurityManager securitymanager = System.getSecurityManager();
        if(securitymanager != null)
            securitymanager.checkWrite(path);
        return fs.setReadOnly(this);
    }    public static File[] listRoots()
    {
        return fs.listRoots();
    }    private static File generateFile(String s, String s1, File file)
        throws IOException
    {
        if(counter == -1)
            counter = (new Random()).nextInt() & 0xffff;
        counter++;
        return new File(file, s + Integer.toString(counter) + s1);
    }    private static String getTempDir()
    {
        if(tmpdir == null)
        {
            GetPropertyAction getpropertyaction = new GetPropertyAction("java.io.tmpdir");
            tmpdir = (String)AccessController.doPrivileged(getpropertyaction);
        }
        return tmpdir;
    }    private static boolean checkAndCreate(String s, SecurityManager securitymanager)
        throws IOException
    {
        if(securitymanager != null)
            try
            {
                securitymanager.checkWrite(s);
            }
            catch(AccessControlException accesscontrolexception)
            {
                throw new SecurityException("Unable to create temporary file");
            }
        return fs.createFileExclusively(s);
    }    public static File createTempFile(String s, String s1, File file)
        throws IOException
    {
        if(s == null)
            throw new NullPointerException();
        if(s.length() < 3)
            throw new IllegalArgumentException("Prefix string too short");
        String s2 = s1 != null ? s1 : ".tmp";
        File file2;
        synchronized(tmpFileLock)
        {
            if(file == null)
                file = new File(getTempDir());
            SecurityManager securitymanager = System.getSecurityManager();
            File file1;
            do
                file1 = generateFile(s, s2, file);
            while(!checkAndCreate(file1.getPath(), securitymanager));
            file2 = file1;
        }
        return file2;
    }    public static File createTempFile(String s, String s1)
        throws IOException
    {
        return createTempFile(s, s1, null);
    }    public int compareTo(File file)
    {
        return fs.compare(this, file);
    }    public int compareTo(Object obj)
    {
        return compareTo((File)obj);
    }    public boolean equals(Object obj)
    {
        if(obj != null && (obj instanceof File))
            return compareTo((File)obj) == 0;
        else
            return false;
    }    public int hashCode()
    {
        return fs.hashCode(this);
    }    public String toString()
    {
        return getPath();
    }    private synchronized void writeObject(ObjectOutputStream objectoutputstream)
        throws IOException
    {
        objectoutputstream.defaultWriteObject();
        objectoutputstream.writeChar(separatorChar);
    }    private synchronized void readObject(ObjectInputStream objectinputstream)
        throws IOException, ClassNotFoundException
    {
        objectinputstream.defaultReadObject();
        char c = objectinputstream.readChar();
        if(c != separatorChar)
            path = path.replace(c, separatorChar);
        path = fs.normalize(path);
        prefixLength = fs.prefixLength(path);
    }    private static FileSystem fs;
    private String path;
    private transient int prefixLength;
    public static final char separatorChar;
    public static final String separator;
    public static final char pathSeparatorChar;
    public static final String pathSeparator;
    private static final Object tmpFileLock = new Object();
    private static int counter = -1;
    private static String tmpdir;
    private static final long serialVersionUID = 0x42da4450e0de4ffL;    static 
    {
        fs = FileSystem.getFileSystem();
        separatorChar = fs.getSeparator();
        separator = "" + separatorChar;
        pathSeparatorChar = fs.getPathSeparator();
        pathSeparator = "" + pathSeparatorChar;
    }
}
以上的内容接在一起！