Java example source code file (GeneralSubtree.java)

This example Java source code file (GeneralSubtree.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

deroutputstream, dervalue, generalname, generalsubtree, invalid, ioexception, maximum, min_default, minimum, string, tag_max, tag_min

The GeneralSubtree.java Java example source code

/*
 * Copyright (c) 1997, 2004, 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 sun.security.x509;

import java.io.*;

import sun.security.util.*;

/**
 * Represent the GeneralSubtree ASN.1 object, whose syntax is:
 * <pre>
 * GeneralSubtree ::= SEQUENCE {
 *    base             GeneralName,
 *    minimum  [0]     BaseDistance DEFAULT 0,
 *    maximum  [1]     BaseDistance OPTIONAL
 * }
 * BaseDistance ::= INTEGER (0..MAX)
 * </pre>
 * @author Amit Kapoor
 * @author Hemma Prafullchandra
 */
public class GeneralSubtree {
    private static final byte TAG_MIN = 0;
    private static final byte TAG_MAX = 1;
    private static final int  MIN_DEFAULT = 0;

    private GeneralName name;
    private int         minimum = MIN_DEFAULT;
    private int         maximum = -1;

    private int myhash = -1;

    /**
     * The default constructor for the class.
     *
     * @params name the GeneralName
     * @params min the minimum BaseDistance
     * @params max the maximum BaseDistance
     */
    public GeneralSubtree(GeneralName name, int min, int max) {
        this.name = name;
        this.minimum = min;
        this.maximum = max;
    }

    /**
     * Create the object from its DER encoded form.
     *
     * @param val the DER encoded from of the same.
     */
    public GeneralSubtree(DerValue val) throws IOException {
        if (val.tag != DerValue.tag_Sequence) {
            throw new IOException("Invalid encoding for GeneralSubtree.");
        }
        name = new GeneralName(val.data.getDerValue(), true);

        // NB. this is always encoded with the IMPLICIT tag
        // The checks only make sense if we assume implicit tagging,
        // with explicit tagging the form is always constructed.
        while (val.data.available() != 0) {
            DerValue opt = val.data.getDerValue();

            if (opt.isContextSpecific(TAG_MIN) && !opt.isConstructed()) {
                opt.resetTag(DerValue.tag_Integer);
                minimum = opt.getInteger();

            } else if (opt.isContextSpecific(TAG_MAX) && !opt.isConstructed()) {
                opt.resetTag(DerValue.tag_Integer);
                maximum = opt.getInteger();
            } else
                throw new IOException("Invalid encoding of GeneralSubtree.");
        }
    }

    /**
     * Return the GeneralName.
     *
     * @return the GeneralName
     */
    public GeneralName getName() {
        //XXXX May want to consider cloning this
        return name;
    }

    /**
     * Return the minimum BaseDistance.
     *
     * @return the minimum BaseDistance. Default is 0 if not set.
     */
    public int getMinimum() {
        return minimum;
    }

    /**
     * Return the maximum BaseDistance.
     *
     * @return the maximum BaseDistance, or -1 if not set.
     */
    public int getMaximum() {
        return maximum;
    }

    /**
     * Return a printable string of the GeneralSubtree.
     */
    public String toString() {
        String s = "\n   GeneralSubtree: [\n" +
            "    GeneralName: " + ((name == null) ? "" : name.toString()) +
            "\n    Minimum: " + minimum;
            if (maximum == -1) {
                s += "\t    Maximum: undefined";
            } else
                s += "\t    Maximum: " + maximum;
            s += "    ]\n";
        return (s);
    }

    /**
     * Compare this GeneralSubtree with another
     *
     * @param other GeneralSubtree to compare to this
     * @returns true if match
     */
    public boolean equals(Object other) {
        if (!(other instanceof GeneralSubtree))
            return false;
        GeneralSubtree otherGS = (GeneralSubtree)other;
        if (this.name == null) {
            if (otherGS.name != null) {
                return false;
            }
        } else {
            if (!((this.name).equals(otherGS.name)))
                return false;
        }
        if (this.minimum != otherGS.minimum)
            return false;
        if (this.maximum != otherGS.maximum)
            return false;
        return true;
    }

    /**
     * Returns the hash code for this GeneralSubtree.
     *
     * @return a hash code value.
     */
    public int hashCode() {
        if (myhash == -1) {
            myhash = 17;
            if (name != null) {
                myhash = 37 * myhash + name.hashCode();
            }
            if (minimum != MIN_DEFAULT) {
                myhash = 37 * myhash + minimum;
            }
            if (maximum != -1) {
                myhash = 37 * myhash + maximum;
            }
        }
        return myhash;
    }

    /**
     * Encode the GeneralSubtree.
     *
     * @params out the DerOutputStream to encode this object to.
     */
    public void encode(DerOutputStream out) throws IOException {
        DerOutputStream seq = new DerOutputStream();

        name.encode(seq);

        if (minimum != MIN_DEFAULT) {
            DerOutputStream tmp = new DerOutputStream();
            tmp.putInteger(minimum);
            seq.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT,
                              false, TAG_MIN), tmp);
        }
        if (maximum != -1) {
            DerOutputStream tmp = new DerOutputStream();
            tmp.putInteger(maximum);
            seq.writeImplicit(DerValue.createTag(DerValue.TAG_CONTEXT,
                              false, TAG_MAX), tmp);
        }
        out.write(DerValue.tag_Sequence, seq);
    }
}