| An immutable valid policy tree node as defined by the PKIX certification
path validation algorithm.
One of the outputs of the PKIX certification path validation
algorithm is a valid policy tree, which includes the policies that
were determined to be valid, how this determination was reached,
and any policy qualifiers encountered. This tree is of depth
n, where n is the length of the certification
path that has been validated.
Most applications will not need to examine the valid policy tree.
They can achieve their policy processing goals by setting the
policy-related parameters in PKIXParameters. However,
the valid policy tree is available for more sophisticated applications,
especially those that process policy qualifiers.
{@link PKIXCertPathValidatorResult#getPolicyTree()
PKIXCertPathValidatorResult.getPolicyTree} returns the root node of the
valid policy tree. The tree can be traversed using the
{@link #getChildren getChildren} and {@link #getParent getParent} methods.
Data about a particular node can be retrieved using other methods of
PolicyNode.
Concurrent Access
All PolicyNode objects must be immutable and
thread-safe. Multiple threads may concurrently invoke the methods defined
in this class on a single PolicyNode object (or more than one)
with no ill effects. This stipulation applies to all public fields and
methods of this class and any added or overridden by subclasses. | 