/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.io;
import java.security.Permission;
import java.security.PermissionCollection;
import java.util.Enumeration;
import java.util.Vector;
/**
* Collects {@link FilePermission} objects and allows to query whether a
* particular permission is implied by it.
*/
final class FilePermissionCollection extends PermissionCollection implements
Serializable {
private static final long serialVersionUID = 2202956749081564585L;
Vector<Permission> permissions = new Vector<Permission>();
/**
* Construct a new FilePermissionCollection
*/
public FilePermissionCollection() {
super();
}
/**
* Add a permission object to the permission collection.
*
* @param permission
* the FilePermission object to add to the collection.
* @throws IllegalArgumentException
* if {@code permission} is not an instance of
* {@code FilePermission}.
* @throws IllegalStateException
* if this collection is read-only.
* @see java.security.PermissionCollection#add(java.security.Permission)
*/
@Override
public void add(Permission permission) {
if (isReadOnly()) {
throw new IllegalStateException();
}
if (permission instanceof FilePermission) {
permissions.addElement(permission);
} else {
throw new IllegalArgumentException(permission.toString());
}
}
/**
* Returns an enumeration for the collection of permissions.
*
* @return a permission enumeration for this permission collection.
* @see java.security.PermissionCollection#elements()
*/
@Override
public Enumeration<Permission> elements() {
return permissions.elements();
}
/**
* Indicates whether this permissions collection implies a specific
* {@code permission}.
*
* @param permission
* the permission to check.
* @see java.security.PermissionCollection#implies(java.security.Permission)
*/
@Override
public boolean implies(Permission permission) {
if (permission instanceof FilePermission) {
FilePermission fp = (FilePermission) permission;
int matchedMask = 0;
int i = 0;
while (i < permissions.size()
&& ((matchedMask & fp.mask) != fp.mask)) {
// Cast will not fail since we added it
matchedMask |= ((FilePermission) permissions.elementAt(i))
.impliesMask(permission);
i++;
}
return ((matchedMask & fp.mask) == fp.mask);
}
return false;
}
}