https://openjdk.java.net/ 
/*
 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.security.cert;

import java.util.Iterator;
import java.util.Set;


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. 

PKIXCertPathValidatorResult.getPolicyTree returns the root node of the valid policy tree. The tree can be traversed using the getChildren and 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. 
Author:     Sean Mullan
Since:      1.4
/**
 * An immutable valid policy tree node as defined by the PKIX certification
 * path validation algorithm.
 *
 * <p>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
 * <i>n</i>, where <i>n</i> is the length of the certification
 * path that has been validated.
 *
 * <p>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 {@code PKIXParameters}. However,
 * the valid policy tree is available for more sophisticated applications,
 * especially those that process policy qualifiers.
 *
 * <p>{@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
 * {@code PolicyNode}.
 *
 * <p><b>Concurrent Access</b>
 * <p>All {@code PolicyNode} objects must be immutable and
 * thread-safe. Multiple threads may concurrently invoke the methods defined
 * in this class on a single {@code 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.
 *
 * @since       1.4
 * @author      Sean Mullan
 */
public interface PolicyNode {

    
Returns the parent of this node, or null if this is the root node. 
Returns:the parent of this node, or null if this is the root node
/**
     * Returns the parent of this node, or {@code null} if this is the
     * root node.
     *
     * @return the parent of this node, or {@code null} if this is the
     * root node
     */
    PolicyNode getParent();

    
Returns an iterator over the children of this node. Any attempts to modify the children of this node through the Iterator's remove method must throw an UnsupportedOperationException. 
Returns:an iterator over the children of this node
/**
     * Returns an iterator over the children of this node. Any attempts to
     * modify the children of this node through the
     * {@code Iterator}'s remove method must throw an
     * {@code UnsupportedOperationException}.
     *
     * @return an iterator over the children of this node
     */
    Iterator<? extends PolicyNode> getChildren();

    
Returns the depth of this node in the valid policy tree.

Returns:the depth of this node (0 for the root node, 1 for its
children, and so on)
/**
     * Returns the depth of this node in the valid policy tree.
     *
     * @return the depth of this node (0 for the root node, 1 for its
     * children, and so on)
     */
    int getDepth();

    
Returns the valid policy represented by this node.

Returns:the String OID of the valid policy represented by this node. For the root node, this method always returns the special anyPolicy OID: "2.5.29.32.0".
/**
     * Returns the valid policy represented by this node.
     *
     * @return the {@code String} OID of the valid policy
     * represented by this node. For the root node, this method always returns
     * the special anyPolicy OID: "2.5.29.32.0".
     */
    String getValidPolicy();

    
Returns the set of policy qualifiers associated with the
valid policy represented by this node.

Returns:an immutable Set of PolicyQualifierInfos. For the root node, this is always an empty Set.
/**
     * Returns the set of policy qualifiers associated with the
     * valid policy represented by this node.
     *
     * @return an immutable {@code Set} of
     * {@code PolicyQualifierInfo}s. For the root node, this
     * is always an empty {@code Set}.
     */
    Set<? extends PolicyQualifierInfo> getPolicyQualifiers();

    
Returns the set of expected policies that would satisfy this
node's valid policy in the next certificate to be processed.

Returns:an immutable Set of expected policy String OIDs. For the root node, this method always returns a Set with one element, the special anyPolicy OID: "2.5.29.32.0".
/**
     * Returns the set of expected policies that would satisfy this
     * node's valid policy in the next certificate to be processed.
     *
     * @return an immutable {@code Set} of expected policy
     * {@code String} OIDs. For the root node, this method
     * always returns a {@code Set} with one element, the
     * special anyPolicy OID: "2.5.29.32.0".
     */
    Set<String> getExpectedPolicies();

    
Returns the criticality indicator of the certificate policy extension
in the most recently processed certificate.

Returns:true if extension marked critical, false otherwise. For the root node, false is always returned.
/**
     * Returns the criticality indicator of the certificate policy extension
     * in the most recently processed certificate.
     *
     * @return {@code true} if extension marked critical,
     * {@code false} otherwise. For the root node, {@code false}
     * is always returned.
     */
    boolean isCritical();
}