# Class JexlPermissions.ClassPermissions

java.lang.Object
org.apache.commons.jexl3.introspection.JexlPermissions.Delegate
org.apache.commons.jexl3.introspection.JexlPermissions.ClassPermissions

All Implemented Interfaces:
  `JexlPermissions`

Enclosing interface:
  `JexlPermissions`

public static final class JexlPermissions.ClassPermissions extends JexlPermissions.Delegate
A permission delegation that augments the RESTRICTED permission with an explicit set of classes.

Typical use case is to deny access to a package - and thus all its classes - but allow a few specific classes.

Note that the newer positive restriction syntax is preferable as in: `RESTRICTED.compose("java.lang { +Class {} }")`.

Since:
  3.3

- ## Nested Class Summary

  ### Nested classes/interfaces inherited from interface JexlPermissions

  `JexlPermissions.ClassPermissions, JexlPermissions.Delegate`

- ## Field Summary

  ### Fields inherited from class JexlPermissions.Delegate

  `base`

  ### Fields inherited from interface JexlPermissions

  `RESTRICTED, UNRESTRICTED`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `ClassPermissions(Class<?>... allow)`
  Creates permissions based on the RESTRICTED set but allowing an explicit set.
  `ClassPermissions(JexlPermissions delegate, Collection<String> allow)`
  Required for compose().

- ## Method Summary

  Modifier and Type
  Method
  Description
  `boolean`
  `allow(Class<?> clazz)`
  Checks whether a class allows JEXL introspection.
  `boolean`
  `allow(Constructor<?> constructor)`
  Checks whether a constructor allows JEXL introspection.
  `boolean`
  `allow(Method method)`
  Checks whether a method allows JEXL introspection.
  `JexlPermissions`
  `compose(String... src)`
  Compose these permissions with a new set.

  ### Methods inherited from class JexlPermissions.Delegate

  `allow, allow`

  ### Methods inherited from class Object

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

  ### Methods inherited from interface JexlPermissions

  `validate, validate, validate, validate, validate`

- ## Constructor Details

  - ### ClassPermissions

    public ClassPermissions(Class<?>... allow)
    Creates permissions based on the RESTRICTED set but allowing an explicit set.
    Parameters:
      `allow` - the set of allowed classes

  - ### ClassPermissions

    public ClassPermissions(JexlPermissions delegate, Collection<String> allow)
    Required for compose().
    Parameters:
      `delegate` - the base to delegate to
      `allow` - the list of class canonical names

- ## Method Details

  - ### allow

    public boolean allow(Class<?> clazz)
    Description copied from interface: `JexlPermissions`
    Checks whether a class allows JEXL introspection.

    If the class disallows JEXL introspection, none of its constructors, methods or fields as well as derived classes are visible to JEXL and cannot be used in scripts or expressions. If one of its super-classes is not allowed, tbe class is not allowed either.

    For interfaces, only methods and fields are disallowed in derived interfaces or implementing classes.

    Specified by:
      `allow` in interface `JexlPermissions`
    Overrides:
      `allow` in class `JexlPermissions.Delegate`
    Parameters:
      `clazz` - the class to check
    Returns:
      true if JEXL is allowed to introspect, false otherwise

  - ### allow

    public boolean allow(Constructor<?> constructor)
    Description copied from interface: `JexlPermissions`
    Checks whether a constructor allows JEXL introspection.

    If a constructor is not allowed, the new operator cannot be used to instantiate its declared class in scripts or expressions.

    Specified by:
      `allow` in interface `JexlPermissions`
    Overrides:
      `allow` in class `JexlPermissions.Delegate`
    Parameters:
      `constructor` - the constructor to check
    Returns:
      true if JEXL is allowed to introspect, false otherwise

  - ### allow

    public boolean allow(Method method)
    Description copied from interface: `JexlPermissions`
    Checks whether a method allows JEXL introspection.

    If a method is not allowed, it cannot resolved and called in scripts or expressions.

    Since methods can be overridden and overloaded, this also checks that no superclass or interface explicitly disallows this methods.

    Specified by:
      `allow` in interface `JexlPermissions`
    Overrides:
      `allow` in class `JexlPermissions.Delegate`
    Parameters:
      `method` - the method to check
    Returns:
      true if JEXL is allowed to introspect, false otherwise

  - ### compose

    public JexlPermissions compose(String... src)
    Description copied from interface: `JexlPermissions`
    Compose these permissions with a new set.

    This is a convenience method meant to easily give access to the packages JEXL is used to integrate with. For instance, using ``JexlPermissions.RESTRICTED`.compose("com.my.app.*")` would extend the restricted set of permissions by allowing the com.my.app package.

    Specified by:
      `compose` in interface `JexlPermissions`
    Overrides:
      `compose` in class `JexlPermissions.Delegate`
    Parameters:
      `src` - the new constraints
    Returns:
      the new permissions