Subclass implementations of this abstract class must provide + * a public constructor that takes a {@code Policy.Parameters} + * object as an input parameter. This constructor also must throw + * an IllegalArgumentException if it does not understand the + * {@code Policy.Parameters} input. + * + * + * @since 1.6 + */ + +public abstract class PolicySpi { + + /** + * Check whether the policy has granted a Permission to a ProtectionDomain. + * + * @param domain the ProtectionDomain to check. + * + * @param permission check whether this permission is granted to the + * specified domain. + * + * @return boolean true if the permission is granted to the domain. + */ + protected abstract boolean engineImplies + (ProtectionDomain domain, Permission permission); + + /** + * Refreshes/reloads the policy configuration. The behavior of this method + * depends on the implementation. For example, calling {@code refresh} + * 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. + */ + protected void engineRefresh() { } + + /** + * Return a PermissionCollection object containing the set of + * permissions granted to the specified CodeSource. + * + *
The default implementation of this method returns + * Policy.UNSUPPORTED_EMPTY_COLLECTION object. This method can be + * overridden if the policy implementation can return a set of + * permissions granted to a CodeSource. + * + * @param codesource the CodeSource to which the returned + * PermissionCollection has been granted. + * + * @return 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. + */ + protected PermissionCollection engineGetPermissions + (CodeSource codesource) { + return Policy.UNSUPPORTED_EMPTY_COLLECTION; + } + + /** + * Return a PermissionCollection object containing the set of + * permissions granted to the specified ProtectionDomain. + * + *
The default implementation of this method returns + * Policy.UNSUPPORTED_EMPTY_COLLECTION object. This method can be + * overridden if the policy implementation can return a set of + * permissions granted to a ProtectionDomain. + * + * @param domain the ProtectionDomain to which the returned + * PermissionCollection has been granted. + * + * @return 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. + */ + protected PermissionCollection engineGetPermissions + (ProtectionDomain domain) { + return Policy.UNSUPPORTED_EMPTY_COLLECTION; + } +}