PolicySpi (Java SE 12 & JDK 12 )
Keywords: java.security.PolicySpi class

Module java.base
Package java.security

## Class PolicySpi

- java.lang.Object
- - java.security.PolicySpi

-     public abstract class PolicySpi
      extends Object

  This class defines the Service Provider Interface (SPI) for the `Policy` class. All the abstract methods in this class must be implemented by each service provider who wishes to supply a Policy implementation.

  Subclass implementations of this abstract class must provide a public constructor that takes a `Policy.Parameters` object as an input parameter. This constructor also must throw an IllegalArgumentException if it does not understand the `Policy.Parameters` input.

  Since:
    1.6

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `PolicySpi()` |

  - ### Method Summary

    Modifier and Type | Method | Description
    --- | --- | ---
    `protected PermissionCollection` | `engineGetPermissions​(CodeSource codesource)` | Return a PermissionCollection object containing the set of permissions granted to the specified CodeSource.
    `protected PermissionCollection` | `engineGetPermissions​(ProtectionDomain domain)` | Return a PermissionCollection object containing the set of permissions granted to the specified ProtectionDomain.
    `protected abstract boolean` | `engineImplies​(ProtectionDomain domain, Permission permission)` | Check whether the policy has granted a Permission to a ProtectionDomain.
    `protected void` | `engineRefresh()` | Refreshes/reloads the policy configuration.

    - ### Methods declared in class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### PolicySpi

          public PolicySpi()

  - ### Method Detail

    - #### engineImplies

          protected abstract boolean engineImplies​(ProtectionDomain domain,
                                                   Permission permission)

      Check whether the policy has granted a Permission to a ProtectionDomain.
      Parameters:
        `domain` - the ProtectionDomain to check.
        `permission` - check whether this permission is granted to the specified domain.
      Returns:
        boolean true if the permission is granted to the domain.

    - #### engineRefresh

          protected void engineRefresh()

      Refreshes/reloads the policy configuration. The behavior of this method depends on the implementation. For example, calling `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.

    - #### engineGetPermissions

          protected PermissionCollection engineGetPermissions​(CodeSource codesource)

      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.

      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.

    - #### engineGetPermissions

          protected PermissionCollection engineGetPermissions​(ProtectionDomain domain)

      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.

      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.