jdk/src/share/classes/java/io/FilePermission.java
changeset 2 90ce3da70b43
child 2057 3acf8e5e2ca0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/io/FilePermission.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,819 @@
+/*
+ * Copyright 1997-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.io;
+
+import java.security.*;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.ArrayList;
+import java.util.StringTokenizer;
+import java.util.Vector;
+import java.util.Collections;
+import java.io.ObjectStreamField;
+import java.io.ObjectOutputStream;
+import java.io.ObjectInputStream;
+import java.io.IOException;
+import sun.security.util.SecurityConstants;
+
+/**
+ * This class represents access to a file or directory.  A FilePermission consists
+ * of a pathname and a set of actions valid for that pathname.
+ * <P>
+ * Pathname is the pathname of the file or directory granted the specified
+ * actions. A pathname that ends in "/*" (where "/" is
+ * the file separator character, <code>File.separatorChar</code>) indicates
+ * all the files and directories contained in that directory. A pathname
+ * that ends with "/-" indicates (recursively) all files
+ * and subdirectories contained in that directory. A pathname consisting of
+ * the special token "&lt;&lt;ALL FILES&gt;&gt;" matches <b>any</b> file.
+ * <P>
+ * Note: A pathname consisting of a single "*" indicates all the files
+ * in the current directory, while a pathname consisting of a single "-"
+ * indicates all the files in the current directory and
+ * (recursively) all files and subdirectories contained in the current
+ * directory.
+ * <P>
+ * The actions to be granted are passed to the constructor in a string containing
+ * a list of one or more comma-separated keywords. The possible keywords are
+ * "read", "write", "execute", and "delete". Their meaning is defined as follows:
+ * <P>
+ * <DL>
+ *    <DT> read <DD> read permission
+ *    <DT> write <DD> write permission
+ *    <DT> execute
+ *    <DD> execute permission. Allows <code>Runtime.exec</code> to
+ *         be called. Corresponds to <code>SecurityManager.checkExec</code>.
+ *    <DT> delete
+ *    <DD> delete permission. Allows <code>File.delete</code> to
+ *         be called. Corresponds to <code>SecurityManager.checkDelete</code>.
+ * </DL>
+ * <P>
+ * The actions string is converted to lowercase before processing.
+ * <P>
+ * Be careful when granting FilePermissions. Think about the implications
+ * of granting read and especially write access to various files and
+ * directories. The "&lt;&lt;ALL FILES>>" permission with write action is
+ * especially dangerous. This grants permission to write to the entire
+ * file system. One thing this effectively allows is replacement of the
+ * system binary, including the JVM runtime environment.
+ *
+ * <p>Please note: Code can always read a file from the same
+ * directory it's in (or a subdirectory of that directory); it does not
+ * need explicit permission to do so.
+ *
+ * @see java.security.Permission
+ * @see java.security.Permissions
+ * @see java.security.PermissionCollection
+ *
+ *
+ * @author Marianne Mueller
+ * @author Roland Schemers
+ * @since 1.2
+ *
+ * @serial exclude
+ */
+
+public final class FilePermission extends Permission implements Serializable {
+
+    /**
+     * Execute action.
+     */
+    private final static int EXECUTE = 0x1;
+    /**
+     * Write action.
+     */
+    private final static int WRITE   = 0x2;
+    /**
+     * Read action.
+     */
+    private final static int READ    = 0x4;
+    /**
+     * Delete action.
+     */
+    private final static int DELETE  = 0x8;
+
+    /**
+     * All actions (read,write,execute,delete)
+     */
+    private final static int ALL     = READ|WRITE|EXECUTE|DELETE;
+    /**
+     * No actions.
+     */
+    private final static int NONE    = 0x0;
+
+    // the actions mask
+    private transient int mask;
+
+    // does path indicate a directory? (wildcard or recursive)
+    private transient boolean directory;
+
+    // is it a recursive directory specification?
+    private transient boolean recursive;
+
+    /**
+     * the actions string.
+     *
+     * @serial
+     */
+    private String actions; // Left null as long as possible, then
+                            // created and re-used in the getAction function.
+
+    // canonicalized dir path. In the case of
+    // directories, it is the name "/blah/*" or "/blah/-" without
+    // the last character (the "*" or "-").
+
+    private transient String cpath;
+
+    // static Strings used by init(int mask)
+    private static final char RECURSIVE_CHAR = '-';
+    private static final char WILD_CHAR = '*';
+
+/*
+    public String toString()
+    {
+        StringBuffer sb = new StringBuffer();
+        sb.append("***\n");
+        sb.append("cpath = "+cpath+"\n");
+        sb.append("mask = "+mask+"\n");
+        sb.append("actions = "+getActions()+"\n");
+        sb.append("directory = "+directory+"\n");
+        sb.append("recursive = "+recursive+"\n");
+        sb.append("***\n");
+        return sb.toString();
+    }
+*/
+
+    private static final long serialVersionUID = 7930732926638008763L;
+
+    /**
+     * initialize a FilePermission object. Common to all constructors.
+     * Also called during de-serialization.
+     *
+     * @param mask the actions mask to use.
+     *
+     */
+    private void init(int mask)
+    {
+
+        if ((mask & ALL) != mask)
+                throw new IllegalArgumentException("invalid actions mask");
+
+        if (mask == NONE)
+                throw new IllegalArgumentException("invalid actions mask");
+
+        if ((cpath = getName()) == null)
+                throw new NullPointerException("name can't be null");
+
+        this.mask = mask;
+
+        if (cpath.equals("<<ALL FILES>>")) {
+            directory = true;
+            recursive = true;
+            cpath = "";
+            return;
+        }
+
+        // store only the canonical cpath if possible
+        cpath = AccessController.doPrivileged(new PrivilegedAction<String>() {
+            public String run() {
+                try {
+                    return sun.security.provider.PolicyFile.canonPath(cpath);
+                } catch (IOException ioe) {
+                    return cpath;
+                }
+            }
+        });
+
+        int len = cpath.length();
+        char last = ((len > 0) ? cpath.charAt(len - 1) : 0);
+
+        if (last == RECURSIVE_CHAR &&
+            cpath.charAt(len - 2) == File.separatorChar) {
+            directory = true;
+            recursive = true;
+            cpath = cpath.substring(0, --len);
+        } else if (last == WILD_CHAR &&
+            cpath.charAt(len - 2) == File.separatorChar) {
+            directory = true;
+            //recursive = false;
+            cpath = cpath.substring(0, --len);
+        } else {
+            // overkill since they are initialized to false, but
+            // commented out here to remind us...
+            //directory = false;
+            //recursive = false;
+        }
+
+        // XXX: at this point the path should be absolute. die if it isn't?
+    }
+
+    /**
+     * Creates a new FilePermission object with the specified actions.
+     * <i>path</i> is the pathname of a file or directory, and <i>actions</i>
+     * contains a comma-separated list of the desired actions granted on the
+     * file or directory. Possible actions are
+     * "read", "write", "execute", and "delete".
+     *
+     * <p>A pathname that ends in "/*" (where "/" is
+     * the file separator character, <code>File.separatorChar</code>)
+     * indicates all the files and directories contained in that directory.
+     * A pathname that ends with "/-" indicates (recursively) all files and
+     * subdirectories contained in that directory. The special pathname
+     * "&lt;&lt;ALL FILES&gt;&gt;" matches any file.
+     *
+     * <p>A pathname consisting of a single "*" indicates all the files
+     * in the current directory, while a pathname consisting of a single "-"
+     * indicates all the files in the current directory and
+     * (recursively) all files and subdirectories contained in the current
+     * directory.
+     *
+     * <p>A pathname containing an empty string represents an empty path.
+     *
+     * @param path the pathname of the file/directory.
+     * @param actions the action string.
+     *
+     * @throws IllegalArgumentException
+     *          If actions is <code>null</code>, empty or contains an action
+     *          other than the specified possible actions.
+     */
+
+    public FilePermission(String path, String actions)
+    {
+        super(path);
+        init(getMask(actions));
+    }
+
+    /**
+     * Creates a new FilePermission object using an action mask.
+     * More efficient than the FilePermission(String, String) constructor.
+     * Can be used from within
+     * code that needs to create a FilePermission object to pass into the
+     * <code>implies</code> method.
+     *
+     * @param path the pathname of the file/directory.
+     * @param mask the action mask to use.
+     */
+
+    // package private for use by the FilePermissionCollection add method
+    FilePermission(String path, int mask)
+    {
+        super(path);
+        init(mask);
+    }
+
+    /**
+     * Checks if this FilePermission object "implies" the specified permission.
+     * <P>
+     * More specifically, this method returns true if:<p>
+     * <ul>
+     * <li> <i>p</i> is an instanceof FilePermission,<p>
+     * <li> <i>p</i>'s actions are a proper subset of this
+     * object's actions, and <p>
+     * <li> <i>p</i>'s pathname is implied by this object's
+     *      pathname. For example, "/tmp/*" implies "/tmp/foo", since
+     *      "/tmp/*" encompasses all files in the "/tmp" directory,
+     *      including the one named "foo".
+     * </ul>
+     *
+     * @param p the permission to check against.
+     *
+     * @return <code>true</code> if the specified permission is not
+     *                  <code>null</code> and is implied by this object,
+     *                  <code>false</code> otherwise.
+     */
+    public boolean implies(Permission p) {
+        if (!(p instanceof FilePermission))
+            return false;
+
+        FilePermission that = (FilePermission) p;
+
+        // we get the effective mask. i.e., the "and" of this and that.
+        // They must be equal to that.mask for implies to return true.
+
+        return ((this.mask & that.mask) == that.mask) && impliesIgnoreMask(that);
+    }
+
+    /**
+     * Checks if the Permission's actions are a proper subset of the
+     * this object's actions. Returns the effective mask iff the
+     * this FilePermission's path also implies that FilePermission's path.
+     *
+     * @param that the FilePermission to check against.
+     * @param exact return immediately if the masks are not equal
+     * @return the effective mask
+     */
+    boolean impliesIgnoreMask(FilePermission that) {
+        if (this.directory) {
+            if (this.recursive) {
+                // make sure that.path is longer then path so
+                // something like /foo/- does not imply /foo
+                if (that.directory) {
+                    return (that.cpath.length() >= this.cpath.length()) &&
+                            that.cpath.startsWith(this.cpath);
+                }  else {
+                    return ((that.cpath.length() > this.cpath.length()) &&
+                        that.cpath.startsWith(this.cpath));
+                }
+            } else {
+                if (that.directory) {
+                    // if the permission passed in is a directory
+                    // specification, make sure that a non-recursive
+                    // permission (i.e., this object) can't imply a recursive
+                    // permission.
+                    if (that.recursive)
+                        return false;
+                    else
+                        return (this.cpath.equals(that.cpath));
+                } else {
+                    int last = that.cpath.lastIndexOf(File.separatorChar);
+                    if (last == -1)
+                        return false;
+                    else {
+                        // this.cpath.equals(that.cpath.substring(0, last+1));
+                        // Use regionMatches to avoid creating new string
+                        return (this.cpath.length() == (last + 1)) &&
+                            this.cpath.regionMatches(0, that.cpath, 0, last+1);
+                    }
+                }
+            }
+        } else if (that.directory) {
+            // if this is NOT recursive/wildcarded,
+            // do not let it imply a recursive/wildcarded permission
+            return false;
+        } else {
+            return (this.cpath.equals(that.cpath));
+        }
+    }
+
+    /**
+     * Checks two FilePermission objects for equality. Checks that <i>obj</i> is
+     * a FilePermission, and has the same pathname and actions as this object.
+     * <P>
+     * @param obj the object we are testing for equality with this object.
+     * @return <code>true</code> if obj is a FilePermission, and has the same
+     *          pathname and actions as this FilePermission object,
+     *          <code>false</code> otherwise.
+     */
+    public boolean equals(Object obj) {
+        if (obj == this)
+            return true;
+
+        if (! (obj instanceof FilePermission))
+            return false;
+
+        FilePermission that = (FilePermission) obj;
+
+        return (this.mask == that.mask) &&
+            this.cpath.equals(that.cpath) &&
+            (this.directory == that.directory) &&
+            (this.recursive == that.recursive);
+    }
+
+    /**
+     * Returns the hash code value for this object.
+     *
+     * @return a hash code value for this object.
+     */
+
+    public int hashCode() {
+        return this.cpath.hashCode();
+    }
+
+    /**
+     * Converts an actions String to an actions mask.
+     *
+     * @param action the action string.
+     * @return the actions mask.
+     */
+    private static int getMask(String actions) {
+
+        int mask = NONE;
+
+        // Null action valid?
+        if (actions == null) {
+            return mask;
+        }
+        // Check against use of constants (used heavily within the JDK)
+        if (actions == SecurityConstants.FILE_READ_ACTION) {
+            return READ;
+        } else if (actions == SecurityConstants.FILE_WRITE_ACTION) {
+            return WRITE;
+        } else if (actions == SecurityConstants.FILE_EXECUTE_ACTION) {
+            return EXECUTE;
+        } else if (actions == SecurityConstants.FILE_DELETE_ACTION) {
+            return DELETE;
+        }
+
+        char[] a = actions.toCharArray();
+
+        int i = a.length - 1;
+        if (i < 0)
+            return mask;
+
+        while (i != -1) {
+            char c;
+
+            // skip whitespace
+            while ((i!=-1) && ((c = a[i]) == ' ' ||
+                               c == '\r' ||
+                               c == '\n' ||
+                               c == '\f' ||
+                               c == '\t'))
+                i--;
+
+            // check for the known strings
+            int matchlen;
+
+            if (i >= 3 && (a[i-3] == 'r' || a[i-3] == 'R') &&
+                          (a[i-2] == 'e' || a[i-2] == 'E') &&
+                          (a[i-1] == 'a' || a[i-1] == 'A') &&
+                          (a[i] == 'd' || a[i] == 'D'))
+            {
+                matchlen = 4;
+                mask |= READ;
+
+            } else if (i >= 4 && (a[i-4] == 'w' || a[i-4] == 'W') &&
+                                 (a[i-3] == 'r' || a[i-3] == 'R') &&
+                                 (a[i-2] == 'i' || a[i-2] == 'I') &&
+                                 (a[i-1] == 't' || a[i-1] == 'T') &&
+                                 (a[i] == 'e' || a[i] == 'E'))
+            {
+                matchlen = 5;
+                mask |= WRITE;
+
+            } else if (i >= 6 && (a[i-6] == 'e' || a[i-6] == 'E') &&
+                                 (a[i-5] == 'x' || a[i-5] == 'X') &&
+                                 (a[i-4] == 'e' || a[i-4] == 'E') &&
+                                 (a[i-3] == 'c' || a[i-3] == 'C') &&
+                                 (a[i-2] == 'u' || a[i-2] == 'U') &&
+                                 (a[i-1] == 't' || a[i-1] == 'T') &&
+                                 (a[i] == 'e' || a[i] == 'E'))
+            {
+                matchlen = 7;
+                mask |= EXECUTE;
+
+            } else if (i >= 5 && (a[i-5] == 'd' || a[i-5] == 'D') &&
+                                 (a[i-4] == 'e' || a[i-4] == 'E') &&
+                                 (a[i-3] == 'l' || a[i-3] == 'L') &&
+                                 (a[i-2] == 'e' || a[i-2] == 'E') &&
+                                 (a[i-1] == 't' || a[i-1] == 'T') &&
+                                 (a[i] == 'e' || a[i] == 'E'))
+            {
+                matchlen = 6;
+                mask |= DELETE;
+
+            } else {
+                // parse error
+                throw new IllegalArgumentException(
+                        "invalid permission: " + actions);
+            }
+
+            // make sure we didn't just match the tail of a word
+            // like "ackbarfaccept".  Also, skip to the comma.
+            boolean seencomma = false;
+            while (i >= matchlen && !seencomma) {
+                switch(a[i-matchlen]) {
+                case ',':
+                    seencomma = true;
+                    /*FALLTHROUGH*/
+                case ' ': case '\r': case '\n':
+                case '\f': case '\t':
+                    break;
+                default:
+                    throw new IllegalArgumentException(
+                            "invalid permission: " + actions);
+                }
+                i--;
+            }
+
+            // point i at the location of the comma minus one (or -1).
+            i -= matchlen;
+        }
+
+        return mask;
+    }
+
+    /**
+     * Return the current action mask. Used by the FilePermissionCollection.
+     *
+     * @return the actions mask.
+     */
+
+    int getMask() {
+        return mask;
+    }
+
+    /**
+     * Return the canonical string representation of the actions.
+     * Always returns present actions in the following order:
+     * read, write, execute, delete.
+     *
+     * @return the canonical string representation of the actions.
+     */
+    private static String getActions(int mask)
+    {
+        StringBuilder sb = new StringBuilder();
+        boolean comma = false;
+
+        if ((mask & READ) == READ) {
+            comma = true;
+            sb.append("read");
+        }
+
+        if ((mask & WRITE) == WRITE) {
+            if (comma) sb.append(',');
+            else comma = true;
+            sb.append("write");
+        }
+
+        if ((mask & EXECUTE) == EXECUTE) {
+            if (comma) sb.append(',');
+            else comma = true;
+            sb.append("execute");
+        }
+
+        if ((mask & DELETE) == DELETE) {
+            if (comma) sb.append(',');
+            else comma = true;
+            sb.append("delete");
+        }
+
+        return sb.toString();
+    }
+
+    /**
+     * Returns the "canonical string representation" of the actions.
+     * That is, this method always returns present actions in the following order:
+     * read, write, execute, delete. For example, if this FilePermission object
+     * allows both write and read actions, a call to <code>getActions</code>
+     * will return the string "read,write".
+     *
+     * @return the canonical string representation of the actions.
+     */
+    public String getActions()
+    {
+        if (actions == null)
+            actions = getActions(this.mask);
+
+        return actions;
+    }
+
+
+    /**
+     * Returns a new PermissionCollection object for storing FilePermission
+     * objects.
+     * <p>
+     * FilePermission objects must be stored in a manner that allows them
+     * to be inserted into the collection in any order, but that also enables the
+     * PermissionCollection <code>implies</code>
+     * method to be implemented in an efficient (and consistent) manner.
+     *
+     * <p>For example, if you have two FilePermissions:
+     * <OL>
+     * <LI>  <code>"/tmp/-", "read"</code>
+     * <LI>  <code>"/tmp/scratch/foo", "write"</code>
+     * </OL>
+     *
+     * <p>and you are calling the <code>implies</code> method with the FilePermission:
+     *
+     * <pre>
+     *   "/tmp/scratch/foo", "read,write",
+     * </pre>
+     *
+     * then the <code>implies</code> function must
+     * take into account both the "/tmp/-" and "/tmp/scratch/foo"
+     * permissions, so the effective permission is "read,write",
+     * and <code>implies</code> returns true. The "implies" semantics for
+     * FilePermissions are handled properly by the PermissionCollection object
+     * returned by this <code>newPermissionCollection</code> method.
+     *
+     * @return a new PermissionCollection object suitable for storing
+     * FilePermissions.
+     */
+
+    public PermissionCollection newPermissionCollection() {
+        return new FilePermissionCollection();
+    }
+
+    /**
+     * WriteObject is called to save the state of the FilePermission
+     * to a stream. The actions are serialized, and the superclass
+     * takes care of the name.
+     */
+    private void writeObject(ObjectOutputStream s)
+        throws IOException
+    {
+        // Write out the actions. The superclass takes care of the name
+        // call getActions to make sure actions field is initialized
+        if (actions == null)
+            getActions();
+        s.defaultWriteObject();
+    }
+
+    /**
+     * readObject is called to restore the state of the FilePermission from
+     * a stream.
+     */
+    private void readObject(ObjectInputStream s)
+         throws IOException, ClassNotFoundException
+    {
+        // Read in the actions, then restore everything else by calling init.
+        s.defaultReadObject();
+        init(getMask(actions));
+    }
+}
+
+/**
+ * A FilePermissionCollection stores a set of FilePermission permissions.
+ * FilePermission objects
+ * must be stored in a manner that allows them to be inserted in any
+ * order, but enable the implies function to evaluate the implies
+ * method.
+ * For example, if you have two FilePermissions:
+ * <OL>
+ * <LI> "/tmp/-", "read"
+ * <LI> "/tmp/scratch/foo", "write"
+ * </OL>
+ * And you are calling the implies function with the FilePermission:
+ * "/tmp/scratch/foo", "read,write", then the implies function must
+ * take into account both the /tmp/- and /tmp/scratch/foo
+ * permissions, so the effective permission is "read,write".
+ *
+ * @see java.security.Permission
+ * @see java.security.Permissions
+ * @see java.security.PermissionCollection
+ *
+ *
+ * @author Marianne Mueller
+ * @author Roland Schemers
+ *
+ * @serial include
+ *
+ */
+
+final class FilePermissionCollection extends PermissionCollection
+implements Serializable {
+
+    // Not serialized; see serialization section at end of class
+    private transient List perms;
+
+    /**
+     * Create an empty FilePermissions object.
+     *
+     */
+
+    public FilePermissionCollection() {
+        perms = new ArrayList();
+    }
+
+    /**
+     * Adds a permission to the FilePermissions. The key for the hash is
+     * permission.path.
+     *
+     * @param permission the Permission object to add.
+     *
+     * @exception IllegalArgumentException - if the permission is not a
+     *                                       FilePermission
+     *
+     * @exception SecurityException - if this FilePermissionCollection object
+     *                                has been marked readonly
+     */
+
+    public void add(Permission permission)
+    {
+        if (! (permission instanceof FilePermission))
+            throw new IllegalArgumentException("invalid permission: "+
+                                               permission);
+        if (isReadOnly())
+            throw new SecurityException(
+                "attempt to add a Permission to a readonly PermissionCollection");
+
+        synchronized (this) {
+            perms.add(permission);
+        }
+    }
+
+    /**
+     * Check and see if this set of permissions implies the permissions
+     * expressed in "permission".
+     *
+     * @param p the Permission object to compare
+     *
+     * @return true if "permission" is a proper subset of a permission in
+     * the set, false if not.
+     */
+
+    public boolean implies(Permission permission)
+    {
+        if (! (permission instanceof FilePermission))
+                return false;
+
+        FilePermission fp = (FilePermission) permission;
+
+        int desired = fp.getMask();
+        int effective = 0;
+        int needed = desired;
+
+        synchronized (this) {
+            int len = perms.size();
+            for (int i = 0; i < len; i++) {
+                FilePermission x = (FilePermission) perms.get(i);
+                if (((needed & x.getMask()) != 0) && x.impliesIgnoreMask(fp)) {
+                    effective |=  x.getMask();
+                    if ((effective & desired) == desired)
+                        return true;
+                    needed = (desired ^ effective);
+                }
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Returns an enumeration of all the FilePermission objects in the
+     * container.
+     *
+     * @return an enumeration of all the FilePermission objects.
+     */
+
+    public Enumeration elements() {
+        // Convert Iterator into Enumeration
+        synchronized (this) {
+            return Collections.enumeration(perms);
+        }
+    }
+
+    private static final long serialVersionUID = 2202956749081564585L;
+
+    // Need to maintain serialization interoperability with earlier releases,
+    // which had the serializable field:
+    //    private Vector permissions;
+
+    /**
+     * @serialField permissions java.util.Vector
+     *     A list of FilePermission objects.
+     */
+    private static final ObjectStreamField[] serialPersistentFields = {
+        new ObjectStreamField("permissions", Vector.class),
+    };
+
+    /**
+     * @serialData "permissions" field (a Vector containing the FilePermissions).
+     */
+    /*
+     * Writes the contents of the perms field out as a Vector for
+     * serialization compatibility with earlier releases.
+     */
+    private void writeObject(ObjectOutputStream out) throws IOException {
+        // Don't call out.defaultWriteObject()
+
+        // Write out Vector
+        Vector permissions = new Vector(perms.size());
+        synchronized (this) {
+            permissions.addAll(perms);
+        }
+
+        ObjectOutputStream.PutField pfields = out.putFields();
+        pfields.put("permissions", permissions);
+        out.writeFields();
+    }
+
+    /*
+     * Reads in a Vector of FilePermissions and saves them in the perms field.
+     */
+    private void readObject(ObjectInputStream in) throws IOException,
+    ClassNotFoundException {
+        // Don't call defaultReadObject()
+
+        // Read in serialized fields
+        ObjectInputStream.GetField gfields = in.readFields();
+
+        // Get the one we want
+        Vector permissions = (Vector)gfields.get("permissions", null);
+        perms = new ArrayList(permissions.size());
+        perms.addAll(permissions);
+    }
+}