Package org.osgi.framework

Class PackagePermission

java.lang.Object
java.security.Permission
java.security.BasicPermission
org.osgi.framework.PackagePermission
All Implemented Interfaces:
Serializable, Guard
public final class PackagePermission extends BasicPermission
A bundle's authority to import or export a package.

A package is a dot-separated string that defines a fully qualified Java package.

For example: 

 org.osgi.service.http

PackagePermission has three actions: exportonly, import and export. The export action, which is deprecated, implies the import action.

See Also:

  • Field Details

    • serialVersionUID

      static final long serialVersionUID
      See Also:

    • EXPORT

      public static final String EXPORT
      Deprecated.
      As of 1.5. Use exportonly instead.
      The action string export. The export action implies the import action.
      See Also:

    • EXPORTONLY

      public static final String EXPORTONLY
      The action string exportonly. The exportonly action does not imply the import action.
      Since:
      1.5
      See Also:

    • IMPORT

      public static final String IMPORT
      The action string import.
      See Also:

    • ACTION_EXPORT

      private static final int ACTION_EXPORT
      See Also:

    • ACTION_IMPORT

      private static final int ACTION_IMPORT
      See Also:

    • ACTION_ALL

      private static final int ACTION_ALL
      See Also:

    • ACTION_NONE

      static final int ACTION_NONE
      See Also:

    • action_mask

      transient int action_mask
      The actions mask.

    • actions

      private volatile String actions
      The actions in canonical form.

    • bundle

      final transient Bundle bundle
      The bundle used by this PackagePermission.

    • filter

      transient Filter filter
      If this PackagePermission was constructed with a filter, this holds a Filter matching object used to evaluate the filter in implies.

    • properties

      private transient volatile Map<String,Object> properties
      This map holds the properties of the permission, used to match a filter in implies. This is not initialized until necessary, and then cached in this object.

  • Constructor Details

    • PackagePermission

      public PackagePermission(String name, String actions)
      Creates a new PackagePermission object.

      The name is specified as a normal Java package name: a dot-separated string. Wildcards may be used. 

       name ::= <package name> | <package name ending in ".*"> | *
      Examples: 
       org.osgi.service.http
 javax.servlet.*
 *
      For the import action, the name can also be a filter expression. The filter gives access to the following attributes:
      • signer - A Distinguished Name chain used to sign the exporting bundle. Wildcards in a DN are not matched according to the filter string rules, but according to the rules defined for a DN chain.
      • location - The location of the exporting bundle.
      • id - The bundle ID of the exporting bundle.
      • name - The symbolic name of the exporting bundle.
      • package.name - The name of the requested package.
      Filter attribute names are processed in a case sensitive manner.

      Package Permissions are granted over all possible versions of a package. A bundle that needs to export a package must have the appropriate PackagePermission for that package; similarly, a bundle that needs to import a package must have the appropriate PackagePermssion for that package.

      Permission is granted for both classes and resources.

      Parameters:
      name - Package name or filter expression. A filter expression can only be specified if the specified action is import.
      actions - exportonly,import (canonical order).
      Throws:
      IllegalArgumentException - If the specified name is a filter expression and either the specified action is not import or the filter has an invalid syntax.

    • PackagePermission

      public PackagePermission(String name, Bundle exportingBundle, String actions)
      Creates a new requested PackagePermission object to be used by code that must perform checkPermission for the import action. PackagePermission objects created with this constructor cannot be added to a PackagePermission permission collection.
      Parameters:
      name - The name of the requested package to import.
      exportingBundle - The bundle exporting the requested package.
      actions - The action import.
      Throws:
      IllegalArgumentException - If the specified action is not import or the name is a filter expression.
      Since:
      1.5

    • PackagePermission

      PackagePermission(String name, int mask)
      Package private constructor used by PackagePermissionCollection.
      Parameters:
      name - package name
      mask - action mask

  • Method Details

    • setTransients

      private void setTransients(String name, int mask)
      Called by constructors and when deserialized.
      Parameters:
      mask - action mask

    • parseActions

      private static int parseActions(String actions)
      Parse action string into action mask.
      Parameters:
      actions - Action string.
      Returns:
      action mask.

    • parseFilter

      private static Filter parseFilter(String filterString)
      Parse filter string into a Filter object.
      Parameters:
      filterString - The filter string to parse.
      Returns:
      a Filter for this bundle. If the specified filterString is not a filter expression, then null is returned.
      Throws:
      IllegalArgumentException - If the filter syntax is invalid.

    • implies

      public boolean implies(Permission p)
      Determines if the specified permission is implied by this object.

      This method checks that the package name of the target is implied by the package name of this object. The list of PackagePermission actions must either match or allow for the list of the target object to imply the target PackagePermission action.

      The permission to export a package implies the permission to import the named package. 

       x.y.*,"export" -> x.y.z,"export" is true
 *,"import" -> x.y, "import"      is true
 *,"export" -> x.y, "import"      is true
 x.y,"export" -> x.y.z, "export"  is false
      Overrides:
      implies in class BasicPermission
      Parameters:
      p - The requested permission.
      Returns:
      true if the specified permission is implied by this object; false otherwise.

    • implies0

      boolean implies0(PackagePermission requested, int effective)
      Internal implies method. Used by the implies and the permission collection implies methods.
      Parameters:
      requested - The requested PackagePermission which has already be validated as a proper argument. The requested PackagePermission must not have a filter expression.
      effective - The effective actions with which to start.
      Returns:
      true if the specified permission is implied by this object; false otherwise.

    • getActions

      public String getActions()
      Returns the canonical string representation of the PackagePermission actions.

      Always returns present PackagePermission actions in the following order: EXPORTONLY,IMPORT.

      Overrides:
      getActions in class BasicPermission
      Returns:
      Canonical string representation of the PackagePermission actions.

    • newPermissionCollection

      public PermissionCollection newPermissionCollection()
      Returns a new PermissionCollection object suitable for storing PackagePermission objects.
      Overrides:
      newPermissionCollection in class BasicPermission
      Returns:
      A new PermissionCollection object.

    • equals

      public boolean equals(Object obj)
      Determines the equality of two PackagePermission objects. This method checks that specified package has the same package name and PackagePermission actions as this PackagePermission object.
      Overrides:
      equals in class BasicPermission
      Parameters:
      obj - The object to test for equality with this PackagePermission object.
      Returns:
      true if obj is a PackagePermission, and has the same package name and actions as this PackagePermission object; false otherwise.

    • hashCode

      public int hashCode()
      Returns the hash code value for this object.
      Overrides:
      hashCode in class BasicPermission
      Returns:
      A hash code value for this object.

    • writeObject

      private void writeObject(ObjectOutputStream s) throws IOException
      WriteObject is called to save the state of this permission object to a stream. The actions are serialized, and the superclass takes care of the name.
      Throws:
      IOException

    • readObject

      private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException
      readObject is called to restore the state of this permission from a stream.
      Throws:
      IOException
      ClassNotFoundException

    • getProperties

      private Map<String,Object> getProperties()
      Called by implies(Permission). This method is only called on a requested permission which cannot have a filter set.
      Returns:
      a map of properties for this permission.