OpenJDK 27 · java.security.PermissionCollection · APIdia, the JavaDoc alternative

Abstract class representing a collection of Permission objects.

With a PermissionCollection, you can:

add a permission to the collection using the add method.
check to see if a particular permission is implied in the collection, using the implies method.
enumerate all the permissions, using the elements method.

When it is desirable to group together a number of Permission objects of the same type, the newPermissionCollection method on that particular type of Permission object should first be called. The default behavior (from the Permission class) is to simply return null. Subclasses of class Permission override the method if they need to store their permissions in a particular PermissionCollection object in order to provide the correct semantics when the PermissionCollection.implies method is called. If a non-null value is returned, that PermissionCollection must be used. If null is returned, then the caller of newPermissionCollection is free to store permissions of the given type in any PermissionCollection they choose (one that uses a Hashtable, one that uses a Vector, etc.).

The collection returned by the Permission.newPermissionCollection method is a homogeneous collection, which stores only Permission objects for a given permission type. A PermissionCollection may also be heterogeneous. For example, Permissions is a PermissionCollection subclass that represents a collection of PermissionCollection objects. That is, its members are each a homogeneous PermissionCollection. For example, a Permission object might have a FilePermissionCollection for all the FilePermission objects, a SocketPermissionCollection for all the SocketPermission objects, and so on. Its add method adds a permission to the appropriate collection.

Whenever a permission is added to a heterogeneous PermissionCollection such as Permissions, and the PermissionCollection doesn't yet contain a PermissionCollection of the specified permission's type, the PermissionCollection should call the newPermissionCollection method on the permission's class to see if it requires a special PermissionCollection. If newPermissionCollection returns null, the PermissionCollection is free to store the permission in any type of PermissionCollection it desires (one using a Hashtable, one using a Vector, etc.). For example, the Permissions object uses a default PermissionCollection implementation that stores the permission objects in a Hashtable.

Subclass implementations of PermissionCollection should assume that they may be called simultaneously from multiple threads, and therefore should be synchronized properly. Furthermore, Enumerations returned via the elements method are not fail-fast. Modifications to a collection should not be performed while enumerating over that collection.

Modifier and Type	Field and Description
private volatile boolean	readOnly
private static final long	serialVersionUID

Access	Constructor and Description
public	PermissionCollection() Constructor for subclasses to call.

Method Summary

Modifier and Type	Method and Description
public abstract void	add(Permission the Permission object to add. permission) Adds a permission object to the current collection of permission objects.
public abstract Enumeration<Permission>	Returns: an enumeration of all the Permissions. elements() Returns an enumeration of all the Permission objects in the collection.
public Stream<Permission>	Returns: a stream of all the Permissions. elementsAsStream() Returns a stream of all the Permission objects in the collection.
public abstract boolean	Returns: `true` if "permission" is implied by the permissions in the collection, `false` if not. implies(Permission the `Permission` object to compare. permission) Checks to see if the specified permission is implied by the collection of `Permission` objects held in this `PermissionCollection`.
public boolean	Returns: `true` if this `PermissionCollection` object is marked as readonly, `false` otherwise. isReadOnly() Returns `true` if this `PermissionCollection` object is marked as readonly.
public void	setReadOnly() Marks this `PermissionCollection` object as "readonly".
public String	Returns: information about this `PermissionCollection` object, as described above. toString() Overrides java.lang.Object.toString. Returns a string describing this `PermissionCollection` object, providing information about all the permissions it contains.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

readOnly	back to summary
private volatile boolean readOnly

serialVersionUID	back to summary
private static final long serialVersionUID Annotations @Serial

PermissionCollection	back to summary
public PermissionCollection() Constructor for subclasses to call.

Method Detail

add back to summary

add	back to summary
public abstract void add(Permission permission) Adds a permission object to the current collection of permission objects. Parameters permission:Permission the Permission object to add. Exceptions SecurityException: if this `PermissionCollection` object has been marked readonly IllegalArgumentException: if this `PermissionCollection` object is a homogeneous collection and the permission is not of the correct type.

public abstract void add(Permission permission)

Adds a permission object to the current collection of permission objects.

Parameters

permission:Permission: the Permission object to add.

Exceptions

SecurityException:: if this PermissionCollection object has been marked readonly
IllegalArgumentException:: if this PermissionCollection object is a homogeneous collection and the permission is not of the correct type.

elements back to summary

elements	back to summary
public abstract Enumeration<Permission> elements() Returns an enumeration of all the Permission objects in the collection. Returns:Enumeration<Permission> an enumeration of all the Permissions. See Also `elementsAsStream()`

public abstract Enumeration<Permission> elements()

Returns an enumeration of all the Permission objects in the collection.

Returns:Enumeration<Permission>: an enumeration of all the Permissions.
See Also: elementsAsStream()

elementsAsStream back to summary

elementsAsStream	back to summary
public Stream<Permission> elementsAsStream() Returns a stream of all the Permission objects in the collection. The collection should not be modified (see `add`) during the execution of the terminal stream operation. Otherwise, the result of the terminal stream operation is undefined. Implementation Specification The default implementation creates a stream whose source is derived from the enumeration returned from a call to `elements()`. Returns:Stream<Permission> a stream of all the Permissions. Since 9

public Stream<Permission> elementsAsStream()

Returns a stream of all the Permission objects in the collection.

The collection should not be modified (see add) during the execution of the terminal stream operation. Otherwise, the result of the terminal stream operation is undefined.

Implementation Specification

The default implementation creates a stream whose source is derived from the enumeration returned from a call to elements().

Returns:Stream<Permission>: a stream of all the Permissions.
Since: 9

implies back to summary

implies	back to summary
public abstract boolean implies(Permission permission) Checks to see if the specified permission is implied by the collection of `Permission` objects held in this `PermissionCollection`. Parameters permission:Permission the `Permission` object to compare. Returns:boolean `true` if "permission" is implied by the permissions in the collection, `false` if not.

public abstract boolean implies(Permission permission)

Checks to see if the specified permission is implied by the collection of Permission objects held in this PermissionCollection.

Parameters

permission:Permission: the Permission object to compare.

Returns:boolean

true if "permission" is implied by the permissions in the collection, false if not.

isReadOnly back to summary

isReadOnly	back to summary
public boolean isReadOnly() Returns `true` if this `PermissionCollection` object is marked as readonly. If it is readonly, no new `Permission` objects can be added to it using `add`. By default, the object is not readonly. It can be set to readonly by a call to `setReadOnly`. Returns:boolean `true` if this `PermissionCollection` object is marked as readonly, `false` otherwise.

public boolean isReadOnly()

Returns true if this PermissionCollection object is marked as readonly. If it is readonly, no new Permission objects can be added to it using add.

By default, the object is not readonly. It can be set to readonly by a call to setReadOnly.

Returns:boolean: true if this PermissionCollection object is marked as readonly, false otherwise.

setReadOnly	back to summary
public void setReadOnly() Marks this `PermissionCollection` object as "readonly". After a `PermissionCollection` object is marked as readonly, no new `Permission` objects can be added to it using `add`.

toString back to summary

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Returns a string describing this `PermissionCollection` object, providing information about all the permissions it contains. The format is: super.toString() ( // enumerate all the Permission // objects and call toString() on them, // one per line.. ) `super.toString` is a call to the `toString` method of this object's superclass, which is `Object`. The result is this collection's type name followed by this object's hashcode, thus enabling clients to differentiate different `PermissionCollection` objects, even if they contain the same permissions. Returns:String information about this `PermissionCollection` object, as described above.

public String toString()

Overrides java.lang.Object.toString.

Returns a string describing this PermissionCollection object, providing information about all the permissions it contains. The format is:

super.toString() (
  // enumerate all the Permission
  // objects and call toString() on them,
  // one per line..
)

super.toString is a call to the toString method of this object's superclass, which is Object. The result is this collection's type name followed by this object's hashcode, thus enabling clients to differentiate different PermissionCollection objects, even if they contain the same permissions.

Returns:String: information about this PermissionCollection object, as described above.

public abstract Class PermissionCollection

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail