/**
* Adds a permission to the <tt>PackagePermission</tt> objects. The key for the hash is the name.
*
* @param permission The <tt>PackagePermission</tt> object to add.
* @throws IllegalArgumentException If the permission is not a <tt>PackagePermission</tt>
* instance.
* @throws SecurityException If this <tt>PackagePermissionCollection</tt> object has been marked
* read-only.
*/
@Override
public void add(Permission permission) {
if (!(permission instanceof PackagePermission))
throw new IllegalArgumentException("invalid permission: " + permission);
if (isReadOnly())
throw new SecurityException(
"attempt to add a Permission to a " + "readonly PermissionCollection");
PackagePermission pp = (PackagePermission) permission;
String name = pp.getName();
PackagePermission existing = (PackagePermission) permissions.get(name);
if (existing != null) {
int oldMask = existing.getMask();
int newMask = pp.getMask();
if (oldMask != newMask) {
permissions.put(name, new PackagePermission(name, oldMask | newMask));
}
} else {
permissions.put(name, permission);
}
if (!all_allowed) {
if (name.equals("*")) all_allowed = true;
}
}
/**
* Determines if the specified permissions implies the permissions expressed in
* <tt>permission</tt>.
*
* @param p The Permission object to compare with this <tt>PackagePermission</tt> object.
* @return <tt>true</tt> if <tt>permission</tt> is a proper subset of a permission in the set;
* <tt>false</tt> otherwise.
*/
@Override
public boolean implies(Permission permission) {
if (!(permission instanceof PackagePermission)) return (false);
PackagePermission pp = (PackagePermission) permission;
PackagePermission x;
int desired = pp.getMask();
int effective = 0;
// short circuit if the "*" Permission was added
if (all_allowed) {
x = (PackagePermission) permissions.get("*");
if (x != null) {
effective |= x.getMask();
if ((effective & desired) == desired) return (true);
}
}
// strategy:
// Check for full match first. Then work our way up the
// name looking for matches on a.b.*
String name = pp.getName();
x = (PackagePermission) permissions.get(name);
if (x != null) {
// we have a direct hit!
effective |= x.getMask();
if ((effective & desired) == desired) return (true);
}
// work our way up the tree...
int last, offset;
offset = name.length() - 1;
while ((last = name.lastIndexOf(".", offset)) != -1) {
name = name.substring(0, last + 1) + "*";
x = (PackagePermission) permissions.get(name);
if (x != null) {
effective |= x.getMask();
if ((effective & desired) == desired) return (true);
}
offset = last - 1;
}
// we don't have to check for "*" as it was already checked
// at the top (all_allowed), so we just return false
return (false);
}