Class Policy
Policy
object is responsible for determining whether code executing
in the Java runtime environment has permission to perform a
security-sensitive operation.
There is only one Policy
object installed in the runtime at any
given time. A Policy
object can be installed by calling the
setPolicy
method. The installed Policy
object can be
obtained by calling the getPolicy
method.
If no Policy
object has been installed in the runtime, a call to
getPolicy
installs an instance of the default Policy
implementation (a default subclass implementation of this abstract class).
The default Policy
implementation can be changed by setting the value
of the policy.provider
security property to the fully qualified
name of the desired Policy
subclass implementation. The system
class loader is used to load this class.
Application code can directly subclass Policy
to provide a custom
implementation. In addition, an instance of a Policy
object can be
constructed by invoking one of the getInstance
factory methods
with a standard type. The default policy type is "JavaPolicy".
Once a Policy
instance has been installed (either by default,
or by calling setPolicy
), the Java runtime invokes its
implies
method when it needs to
determine whether executing code (encapsulated in a ProtectionDomain)
can perform SecurityManager-protected operations. How a Policy
object retrieves its policy data is up to the Policy
implementation
itself. The policy data may be stored, for example, in a flat ASCII file,
in a serialized binary file of the Policy
class, or in a database.
The refresh
method causes the policy object to
refresh/reload its data. This operation is implementation-dependent.
For example, if the policy object stores its data in configuration files,
calling refresh
will cause it to re-read the configuration
policy files. If a refresh operation is not supported, this method does
nothing. Note that refreshed policy may not have an effect on classes
in a particular ProtectionDomain. This is dependent on the policy
provider's implementation of the implies
method and its PermissionCollection caching strategy.
- Since:
- 1.2
- See Also:
-
Nested Class Summary
Modifier and TypeClassDescriptionstatic interface
Deprecated, for removal: This API element is subject to removal in a future version.This class is only useful in conjunction with the Security Manager, which is deprecated and subject to removal in a future release. -
Field Summary
Modifier and TypeFieldDescriptionstatic final PermissionCollection
Deprecated, for removal: This API element is subject to removal in a future version.A read-only empty PermissionCollection instance. -
Constructor Summary
ConstructorDescriptionPolicy()
Deprecated, for removal: This API element is subject to removal in a future version.Constructor for subclasses to call. -
Method Summary
Modifier and TypeMethodDescriptionstatic Policy
getInstance
(String type, Policy.Parameters params) Deprecated, for removal: This API element is subject to removal in a future version.Returns a Policy object of the specified type.static Policy
getInstance
(String type, Policy.Parameters params, String provider) Deprecated, for removal: This API element is subject to removal in a future version.Returns aPolicy
object of the specified type.static Policy
getInstance
(String type, Policy.Parameters params, Provider provider) Deprecated, for removal: This API element is subject to removal in a future version.Returns aPolicy
object of the specified type.Deprecated, for removal: This API element is subject to removal in a future version.ReturnPolicy
parameters.getPermissions
(CodeSource codesource) Deprecated, for removal: This API element is subject to removal in a future version.Return a PermissionCollection object containing the set of permissions granted to the specified CodeSource.getPermissions
(ProtectionDomain domain) Deprecated, for removal: This API element is subject to removal in a future version.Return a PermissionCollection object containing the set of permissions granted to the specified ProtectionDomain.static Policy
Deprecated, for removal: This API element is subject to removal in a future version.Returns the installedPolicy
object.Deprecated, for removal: This API element is subject to removal in a future version.Return theProvider
of this policy.getType()
Deprecated, for removal: This API element is subject to removal in a future version.Return the type of thisPolicy
.boolean
implies
(ProtectionDomain domain, Permission permission) Deprecated, for removal: This API element is subject to removal in a future version.Evaluates the global policy for the permissions granted to the ProtectionDomain and tests whether the permission is granted.void
refresh()
Deprecated, for removal: This API element is subject to removal in a future version.Refreshes/reloads the policy configuration.static void
Deprecated, for removal: This API element is subject to removal in a future version.Sets the system-widePolicy
object.
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Field Details
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UNSUPPORTED_EMPTY_COLLECTION
Deprecated, for removal: This API element is subject to removal in a future version.A read-only empty PermissionCollection instance.- Since:
- 1.6
-
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Constructor Details
-
Policy
public Policy()Deprecated, for removal: This API element is subject to removal in a future version.Constructor for subclasses to call.
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Method Details
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getPolicy
Deprecated, for removal: This API element is subject to removal in a future version.Returns the installedPolicy
object. This value should not be cached, as it may be changed by a call tosetPolicy
. This method first callsSecurityManager.checkPermission
with aSecurityPermission("getPolicy")
permission to ensure it's ok to get thePolicy
object.- Returns:
- the installed Policy.
- Throws:
SecurityException
- if a security manager exists and itscheckPermission
method doesn't allow getting thePolicy
object.- See Also:
-
setPolicy
Deprecated, for removal: This API element is subject to removal in a future version.Sets the system-widePolicy
object. This method first callsSecurityManager.checkPermission
with aSecurityPermission("setPolicy")
permission to ensure it's ok to set the Policy.- Parameters:
p
- the new systemPolicy
object.- Throws:
SecurityException
- if a security manager exists and itscheckPermission
method doesn't allow setting the Policy.- See Also:
-
getInstance
public static Policy getInstance(String type, Policy.Parameters params) throws NoSuchAlgorithmException Deprecated, for removal: This API element is subject to removal in a future version.Returns a Policy object of the specified type.This method traverses the list of registered security providers, starting with the most preferred provider. A new
Policy
object encapsulating thePolicySpi
implementation from the first provider that supports the specified type is returned.Note that the list of registered providers may be retrieved via the
Security.getProviders()
method.- Implementation Note:
- The JDK Reference Implementation additionally uses the
jdk.security.provider.preferred
Security
property to determine the preferred provider order for the specified algorithm. This may be different than the order of providers returned bySecurity.getProviders()
. - Parameters:
type
- the specified Policy type. See the Policy section in the Java Security Standard Algorithm Names Specification for a list of standard Policy types.params
- parameters for thePolicy
, which may benull
.- Returns:
- the new
Policy
object - Throws:
IllegalArgumentException
- if the specified parameters are not understood by thePolicySpi
implementation from the selectedProvider
NoSuchAlgorithmException
- if noProvider
supports aPolicySpi
implementation for the specified typeNullPointerException
- iftype
isnull
SecurityException
- if the caller does not have permission to get aPolicy
instance for the specified type.- Since:
- 1.6
- See Also:
-
getInstance
public static Policy getInstance(String type, Policy.Parameters params, String provider) throws NoSuchProviderException, NoSuchAlgorithmException Deprecated, for removal: This API element is subject to removal in a future version.Returns aPolicy
object of the specified type.A new
Policy
object encapsulating thePolicySpi
implementation from the specified provider is returned. The specified provider must be registered in the provider list.Note that the list of registered providers may be retrieved via the
Security.getProviders()
method.- Parameters:
type
- the specified Policy type. See the Policy section in the Java Security Standard Algorithm Names Specification for a list of standard Policy types.params
- parameters for thePolicy
, which may benull
.provider
- the provider.- Returns:
- the new
Policy
object - Throws:
IllegalArgumentException
- if the specified provider isnull
or empty, or if the specified parameters are not understood by thePolicySpi
implementation from the specified providerNoSuchAlgorithmException
- if the specified provider does not support aPolicySpi
implementation for the specified typeNoSuchProviderException
- if the specified provider is not registered in the security provider listNullPointerException
- iftype
isnull
SecurityException
- if the caller does not have permission to get aPolicy
instance for the specified type- Since:
- 1.6
- See Also:
-
getInstance
public static Policy getInstance(String type, Policy.Parameters params, Provider provider) throws NoSuchAlgorithmException Deprecated, for removal: This API element is subject to removal in a future version.Returns aPolicy
object of the specified type.A new
Policy
object encapsulating thePolicySpi
implementation from the specified provider is returned. Note that the specified provider does not have to be registered in the provider list.- Parameters:
type
- the specified Policy type. See the Policy section in the Java Security Standard Algorithm Names Specification for a list of standard Policy types.params
- parameters for thePolicy
, which may benull
.provider
- theProvider
.- Returns:
- the new
Policy
object - Throws:
IllegalArgumentException
- if the specifiedProvider
isnull
, or if the specified parameters are not understood by thePolicySpi
implementation from the specifiedProvider
NoSuchAlgorithmException
- if the specifiedProvider
does not support aPolicySpi
implementation for the specified typeNullPointerException
- iftype
isnull
SecurityException
- if the caller does not have permission to get aPolicy
instance for the specified type- Since:
- 1.6
- See Also:
-
getProvider
Deprecated, for removal: This API element is subject to removal in a future version.Return theProvider
of this policy.This
Policy
instance will only have a provider if it was obtained via a call toPolicy.getInstance
. Otherwise this method returnsnull
.- Returns:
- the
Provider
of this policy, ornull
. - Since:
- 1.6
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getType
Deprecated, for removal: This API element is subject to removal in a future version.Return the type of thisPolicy
.This
Policy
instance will only have a type if it was obtained via a call toPolicy.getInstance
. Otherwise this method returnsnull
.- Returns:
- the type of this
Policy
, ornull
. - Since:
- 1.6
-
getParameters
Deprecated, for removal: This API element is subject to removal in a future version.ReturnPolicy
parameters.This
Policy
instance will only have parameters if it was obtained via a call toPolicy.getInstance
. Otherwise this method returnsnull
.- Returns:
Policy
parameters, ornull
.- Since:
- 1.6
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getPermissions
Deprecated, for removal: This API element is subject to removal in a future version.Return a PermissionCollection object containing the set of permissions granted to the specified CodeSource.Applications are discouraged from calling this method since this operation may not be supported by all policy implementations. Applications should solely rely on the
implies
method to perform policy checks. If an application absolutely must call a getPermissions method, it should callgetPermissions(ProtectionDomain)
.The default implementation of this method returns Policy.UNSUPPORTED_EMPTY_COLLECTION. This method can be overridden if the policy implementation can return a set of permissions granted to a CodeSource.
- Parameters:
codesource
- the CodeSource to which the returned PermissionCollection has been granted.- Returns:
- a set of permissions granted to the specified CodeSource. If this operation is supported, the returned set of permissions must be a new mutable instance and it must support heterogeneous Permission types. If this operation is not supported, Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
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getPermissions
Deprecated, for removal: This API element is subject to removal in a future version.Return a PermissionCollection object containing the set of permissions granted to the specified ProtectionDomain.Applications are discouraged from calling this method since this operation may not be supported by all policy implementations. Applications should rely on the
implies
method to perform policy checks.The default implementation of this method first retrieves the permissions returned via
getPermissions(CodeSource)
(the CodeSource is taken from the specified ProtectionDomain), as well as the permissions located inside the specified ProtectionDomain. All of these permissions are then combined and returned in a new PermissionCollection object. IfgetPermissions(CodeSource)
returns Policy.UNSUPPORTED_EMPTY_COLLECTION, then this method returns the permissions contained inside the specified ProtectionDomain in a new PermissionCollection object.This method can be overridden if the policy implementation supports returning a set of permissions granted to a ProtectionDomain.
- Parameters:
domain
- the ProtectionDomain to which the returned PermissionCollection has been granted.- Returns:
- a set of permissions granted to the specified ProtectionDomain. If this operation is supported, the returned set of permissions must be a new mutable instance and it must support heterogeneous Permission types. If this operation is not supported, Policy.UNSUPPORTED_EMPTY_COLLECTION is returned.
- Since:
- 1.4
-
implies
Deprecated, for removal: This API element is subject to removal in a future version.Evaluates the global policy for the permissions granted to the ProtectionDomain and tests whether the permission is granted.- Parameters:
domain
- the ProtectionDomain to testpermission
- the Permission object to be tested for implication.- Returns:
true
if "permission" is a proper subset of a permission granted to this ProtectionDomain.- Since:
- 1.4
- See Also:
-
refresh
public void refresh()Deprecated, for removal: This API element is subject to removal in a future version.Refreshes/reloads the policy configuration. The behavior of this method depends on the implementation. For example, callingrefresh
on a file-based policy will cause the file to be re-read.The default implementation of this method does nothing. This method should be overridden if a refresh operation is supported by the policy implementation.
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