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

This class represents a heterogeneous collection of permissions. That is, it contains different types of Permission objects, organized into PermissionCollection objects. For example, if any java.io.FilePermission objects are added to an instance of this class, they are all stored in a single PermissionCollection. It is the PermissionCollection returned by a call to the newPermissionCollection method in the FilePermission class. Similarly, any java.lang.RuntimePermission objects are stored in the PermissionCollection returned by a call to the newPermissionCollection method in the RuntimePermission class. Thus, this class represents a collection of PermissionCollection objects.

When the add method is called to add a Permission, the Permission is stored in the appropriate PermissionCollection. If no such collection exists yet, the Permission object's class is determined and the newPermissionCollection method is called on that class to create the PermissionCollection and add it to the Permissions object. If newPermissionCollection returns null, then a default PermissionCollection that uses a hashtable will be created and used. Each hashtable entry stores a Permission object as both the key and the value.

Enumerations returned via the elements method are not fail-fast. Modifications to a collection should not be performed while enumerating over that collection.

Field Summary

Modifier and Type	Field and Description
pack-priv PermissionCollection	allPermission
private transient boolean	hasUnresolved
private transient ConcurrentHashMap<Class<?>, PermissionCollection>	permsMap Key is permissions Class, value is `PermissionCollection` for that class.
private static final ObjectStreamField[]	serialPersistentFields
private static final long	serialVersionUID Hides java.security.PermissionCollection.serialVersionUID.

Constructor Summary

Access	Constructor and Description
public	Permissions() Creates a new `Permissions` object containing no `PermissionCollection` objects.

Method Summary

Modifier and Type	Method and Description
public void	add(Permission the `Permission` object to add. permission) Implements abstract java.security.PermissionCollection.add. Adds a `Permission` object to the `PermissionCollection` for the class the permission belongs to.
private PermissionCollection	createPermissionCollection(Permission p, boolean createEmpty)
public Enumeration<Permission>	Returns: an enumeration of all the `Permission` objects. elements() Implements abstract java.security.PermissionCollection.elements. Returns an enumeration of all the `Permission` objects in all the `PermissionCollection` objects in this `Permissions` object.
private PermissionCollection	getPermissionCollection(Permission p, boolean createEmpty) Gets the `PermissionCollection` in this `Permissions` object for permissions whose type is the same as that of p.
private PermissionCollection	Returns: PermissionCollection containing the unresolved permissions, or `null` if there were no unresolved permissions of type p. getUnresolvedPermissions(Permission the type of unresolved permission to resolve p) Resolves any unresolved permissions of type p.
public boolean	Returns: `true` if "permission" is implied by the permissions in the `PermissionCollection` it belongs to, `false` if not. implies(Permission the `Permission` object to check. permission) Implements abstract java.security.PermissionCollection.implies. Checks to see if this object's `PermissionCollection` for permissions of the specified permission's class implies the permissions expressed in the permission object.
private void	readObject(ObjectInputStream in)
private void	writeObject(ObjectOutputStream out)

Inherited from java.security.PermissionCollection:: elementsAsStream isReadOnly setReadOnly toString

Field Detail

allPermission	back to summary
pack-priv PermissionCollection allPermission

hasUnresolved	back to summary
private transient boolean hasUnresolved

permsMap	back to summary
private transient ConcurrentHashMap<Class<?>, PermissionCollection> permsMap Key is permissions Class, value is `PermissionCollection` for that class. Not serialized; see serialization section at end of class.

serialPersistentFields	back to summary
private static final ObjectStreamField[] serialPersistentFields Annotations @Serial Serial Fields: perms:`Hashtable` A table of the `Permission` classes and `PermissionCollection` objects. allPermission:`PermissionCollection`

serialVersionUID	back to summary
private static final long serialVersionUID Hides java.security.PermissionCollection.serialVersionUID. Annotations @Serial

Constructor Detail

Permissions	back to summary
public Permissions() Creates a new `Permissions` object containing no `PermissionCollection` objects.

Method Detail

add back to summary

add	back to summary
public void add(Permission permission) Implements abstract java.security.PermissionCollection.add. Adds a `Permission` object to the `PermissionCollection` for the class the permission belongs to. For example, if permission is a `FilePermission`, it is added to the `FilePermissionCollection` stored in this `Permissions` object. This method creates a new `PermissionCollection` object (and adds the permission to it) if an appropriate collection does not yet exist. Parameters permission:Permission the `Permission` object to add. Annotations @Override @SuppressWarnings:removal Exceptions SecurityException: if this `Permissions` object is marked as readonly. See Also `PermissionCollection#isReadOnly()`

public void add(Permission permission)

Implements abstract java.security.PermissionCollection.add.

Adds a Permission object to the PermissionCollection for the class the permission belongs to. For example, if permission is a FilePermission, it is added to the FilePermissionCollection stored in this Permissions object. This method creates a new PermissionCollection object (and adds the permission to it) if an appropriate collection does not yet exist.

Parameters

permission:Permission: the Permission object to add.

Annotations

@Override
@SuppressWarnings:removal

Exceptions

SecurityException:: if this Permissions object is marked as readonly.

See Also

PermissionCollection#isReadOnly()

createPermissionCollection	back to summary
private PermissionCollection createPermissionCollection(Permission p, boolean createEmpty)

elements back to summary

elements	back to summary
public Enumeration<Permission> elements() Implements abstract java.security.PermissionCollection.elements. Returns an enumeration of all the `Permission` objects in all the `PermissionCollection` objects in this `Permissions` object. Returns:Enumeration<Permission> an enumeration of all the `Permission` objects. Annotations @Override

public Enumeration<Permission> elements()

Implements abstract java.security.PermissionCollection.elements.

Returns an enumeration of all the Permission objects in all the PermissionCollection objects in this Permissions object.

Returns:Enumeration<Permission>

an enumeration of all the Permission objects.

Annotations

@Override

getPermissionCollection back to summary

getPermissionCollection	back to summary
private PermissionCollection getPermissionCollection(Permission p, boolean createEmpty) Gets the `PermissionCollection` in this `Permissions` object for permissions whose type is the same as that of p. For example, if p is a `FilePermission`, the `FilePermissionCollection` stored in this `Permissions` object will be returned. If `createEmpty` is `true`, this method creates a new `PermissionCollection` object for the specified type of permission objects if one does not yet exist. To do so, it first calls the `newPermissionCollection` method on p. Subclasses of class `Permission` override that 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 the call returns a `PermissionCollection`, that collection is stored in this `Permissions` object. If the call returns `null` and `createEmpty` is `true`, then this method instantiates and stores a default `PermissionCollection` that uses a hashtable to store its permission objects. `createEmpty` is ignored when creating empty `PermissionCollection` for unresolved permissions because of the overhead of determining the `PermissionCollection` to use. `createEmpty` should be set to `false` when this method is invoked from implies() because it incurs the additional overhead of creating and adding an empty `PermissionCollection` that will just return `false`. It should be set to `true` when invoked from add().

private PermissionCollection getPermissionCollection(Permission p, boolean createEmpty)

Gets the PermissionCollection in this Permissions object for permissions whose type is the same as that of p. For example, if p is a FilePermission, the FilePermissionCollection stored in this Permissions object will be returned. If createEmpty is true, this method creates a new PermissionCollection object for the specified type of permission objects if one does not yet exist. To do so, it first calls the newPermissionCollection method on p. Subclasses of class Permission override that 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 the call returns a PermissionCollection, that collection is stored in this Permissions object. If the call returns null and createEmpty is true, then this method instantiates and stores a default PermissionCollection that uses a hashtable to store its permission objects. createEmpty is ignored when creating empty PermissionCollection for unresolved permissions because of the overhead of determining the PermissionCollection to use. createEmpty should be set to false when this method is invoked from implies() because it incurs the additional overhead of creating and adding an empty PermissionCollection that will just return false. It should be set to true when invoked from add().

getUnresolvedPermissions back to summary

getUnresolvedPermissions	back to summary
private PermissionCollection getUnresolvedPermissions(Permission p) Resolves any unresolved permissions of type p. Parameters p:Permission the type of unresolved permission to resolve Returns:PermissionCollection PermissionCollection containing the unresolved permissions, or `null` if there were no unresolved permissions of type p. Annotations @SuppressWarnings:removal

private PermissionCollection getUnresolvedPermissions(Permission p)

Resolves any unresolved permissions of type p.

Parameters

p:Permission: the type of unresolved permission to resolve

Returns:PermissionCollection

PermissionCollection containing the unresolved permissions, or null if there were no unresolved permissions of type p.

Annotations

@SuppressWarnings:removal

implies back to summary

implies	back to summary
public boolean implies(Permission permission) Implements abstract java.security.PermissionCollection.implies. Checks to see if this object's `PermissionCollection` for permissions of the specified permission's class implies the permissions expressed in the permission object. Returns `true` if the combination of permissions in the appropriate `PermissionCollection` (e.g., a `FilePermissionCollection` for a `FilePermission`) together imply the specified permission. For example, suppose there is a `FilePermissionCollection` in this `Permissions` object, and it contains one `FilePermission` that specifies "read" access for all files in all subdirectories of the "/tmp" directory, and another `FilePermission` that specifies "write" access for all files in the "/tmp/scratch/foo" directory. Then if the `implies` method is called with a permission specifying both "read" and "write" access to files in the "/tmp/scratch/foo" directory, `true` is returned. Additionally, if this `PermissionCollection` contains the `AllPermission`, this method will always return `true`. Parameters permission:Permission the `Permission` object to check. Returns:boolean `true` if "permission" is implied by the permissions in the `PermissionCollection` it belongs to, `false` if not. Annotations @Override

public boolean implies(Permission permission)

Implements abstract java.security.PermissionCollection.implies.

Checks to see if this object's PermissionCollection for permissions of the specified permission's class implies the permissions expressed in the permission object. Returns true if the combination of permissions in the appropriate PermissionCollection (e.g., a FilePermissionCollection for a FilePermission) together imply the specified permission.

For example, suppose there is a FilePermissionCollection in this Permissions object, and it contains one FilePermission that specifies "read" access for all files in all subdirectories of the "/tmp" directory, and another FilePermission that specifies "write" access for all files in the "/tmp/scratch/foo" directory. Then if the implies method is called with a permission specifying both "read" and "write" access to files in the "/tmp/scratch/foo" directory, true is returned.

Additionally, if this PermissionCollection contains the AllPermission, this method will always return true.

Parameters

permission:Permission: the Permission object to check.

Returns:boolean

true if "permission" is implied by the permissions in the PermissionCollection it belongs to, false if not.

Annotations

@Override

readObject	back to summary
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException Annotations @Serial @SuppressWarnings:removal

writeObject	back to summary
private void writeObject(ObjectOutputStream out) throws IOException Annotations @Serial Serial data Default fields.

public final Class Permissions

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