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	/*
	* Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.io;

	import java.net.URI;
	import java.nio.file.InvalidPathException;
	import java.security.*;
	import java.util.Enumeration;
	import java.util.List;
	import java.util.ArrayList;
	import java.util.Vector;
	import java.util.Collections;

	import sun.nio.fs.DefaultFileSystemProvider;
	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. Such a pathname is called
	* a wildcard pathname. Otherwise, it's a simple pathname.
	* <P>
	* A pathname consisting of the special token {@literal "<<ALL FILES>>"}
	* 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", "delete", and "readlink". Their meaning is
	* defined as follows:
	*
	* <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>.
	* <DT> readlink
	* <DD> read link permission. Allows the target of a
	* <a href="../nio/file/package-summary.html#links">symbolic link</a>
	* to be read by invoking the {@link java.nio.file.Files#readSymbolicLink
	* readSymbolicLink } method.
	* </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 {@literal "<<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;
	/**
	* Read link action.
	*/
	private final static int READLINK = 0x10;

	/**
	* All actions (read,write,execute,delete,readlink)
	*/
	private final static int ALL = READ\|WRITE\|EXECUTE\|DELETE\|READLINK;
	/**
	* 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;

	private transient boolean allFiles; // whether this is <<ALL FILES>>
	private transient boolean invalid; // whether input path is invalid

	// 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;

	/**
	* Always use the internal default file system, in case it was modified
	* with java.nio.file.spi.DefaultFileSystemProvider.
	*/
	private static final java.nio.file.FileSystem builtInFS =
	DefaultFileSystemProvider.create()
	.getFileSystem(URI.create("file:///"));

	/**
	* 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>>")) {
	allFiles = true;
	directory = true;
	recursive = true;
	cpath = "";
	return;
	}

	// Validate path by platform's default file system
	// Note: this check does not apply during FilePermission
	// class initialization.
	if (builtInFS != null) {
	try {
	String name = cpath.endsWith("*") ?
	cpath.substring(0, cpath.length() - 1) + "-" : cpath;
	builtInFS.getPath(new File(name).getPath());
	} catch (InvalidPathException ipe) {
	invalid = true;
	return;
	}
	}

	// store only the canonical cpath if possible
	cpath = AccessController.doPrivileged(new PrivilegedAction<String>() {
	public String run() {
	try {
	String path = cpath;
	if (cpath.endsWith("*")) {
	// call getCanonicalPath with a path with wildcard character
	// replaced to avoid calling it with paths that are
	// intended to match all entries in a directory
	path = path.substring(0, path.length()-1) + "-";
	path = new File(path).getCanonicalPath();
	return path.substring(0, path.length()-1) + "*";
	} else {
	return new File(path).getCanonicalPath();
	}
	} 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", "delete", and "readlink".
	*
	* <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
	* "<<ALL FILES>>" 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:
	* <ul>
	* <li> <i>p</i> is an instanceof FilePermission,
	* <li> <i>p</i>'s actions are a proper subset of this
	* object's actions, and
	* <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>
	* <P>
	* Precisely, a simple pathname implies another simple pathname
	* if and only if they are equal. A simple pathname never implies
	* a wildcard pathname. A wildcard pathname implies another wildcard
	* pathname if and only if all simple pathnames implied by the latter
	* are implied by the former. A wildcard pathname implies a simple
	* pathname if and only if
	* <ul>
	* <li>if the wildcard flag is "*", the simple pathname's path
	* must be right inside the wildcard pathname's path.
	* <li>if the wildcard flag is "-", the simple pathname's path
	* must be recursively inside the wildcard pathname's path.
	* </ul>
	* <P>
	* {@literal "<<ALL FILES>>"} implies every other pathname. No pathname,
	* except for {@literal "<<ALL FILES>>"} itself, implies
	* {@literal "<<ALL FILES>>"}.
	*
	* @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.
	* @return the effective mask
	*/
	boolean impliesIgnoreMask(FilePermission that) {
	if (this == that) {
	return true;
	}
	if (allFiles) {
	return true;
	}
	if (this.invalid \|\| that.invalid) {
	return false;
	}
	if (that.allFiles) {
	return false;
	}
	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.
	*
	* @implNote More specifically, two pathnames are the same if and only if
	* they have the same wildcard flag and their
	* {@code npath} are equal. Or they are both {@literal "<<ALL FILES>>"}.
	*
	* @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;

	if (this.invalid \|\| that.invalid) {
	return false;
	}
	return (this.mask == that.mask) &&
	(this.allFiles == that.allFiles) &&
	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 0;
	}

	/**
	* Converts an actions String to an actions mask.
	*
	* @param actions the action string.
	* @return the actions mask.
	*/
	private static int getMask(String actions) {
	int mask = NONE;

	// Null action valid?
	if (actions == null) {
	return mask;
	}

	// Use object identity comparison against known-interned strings for
	// performance benefit (these values are 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;
	} else if (actions == SecurityConstants.FILE_READLINK_ACTION) {
	return READLINK;
	}

	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 if (i >= 7 && (a[i-7] == 'r' \|\| a[i-7] == 'R') &&
	(a[i-6] == 'e' \|\| a[i-6] == 'E') &&
	(a[i-5] == 'a' \|\| a[i-5] == 'A') &&
	(a[i-4] == 'd' \|\| a[i-4] == 'D') &&
	(a[i-3] == 'l' \|\| a[i-3] == 'L') &&
	(a[i-2] == 'i' \|\| a[i-2] == 'I') &&
	(a[i-1] == 'n' \|\| a[i-1] == 'N') &&
	(a[i] == 'k' \|\| a[i] == 'K'))
	{
	matchlen = 8;
	mask \|= READLINK;

	} 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;
	break;
	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, readlink.
	*
	* @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");
	}

	if ((mask & READLINK) == READLINK) {
	if (comma) sb.append(',');
	else comma = true;
	sb.append("readlink");
	}

	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, readlink. 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<Permission> perms;

	/**
	* Create an empty FilePermissionCollection object.
	*/
	public FilePermissionCollection() {
	perms = new ArrayList<>();
	}

	/**
	* Adds a permission to the FilePermissionCollection. 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 permission 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<Permission> 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<Permission> 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
	@SuppressWarnings("unchecked")
	Vector<Permission> permissions = (Vector<Permission>)gfields.get("permissions", null);
	perms = new ArrayList<>(permissions.size());
	for (Permission perm : permissions) {
	perms.add(perm);
	}
	}
	}

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