/*

 * Copyright (c) 2002, 2014, 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 javax.management.remote;

import java.io.IOException;

import java.io.InvalidObjectException;

import java.io.ObjectInputStream;

import java.io.Serializable;

import java.security.Principal;

/**

 * <p>The identity of a remote client of the JMX Remote API.</p>

 *

 * <p>Principals such as this <code>JMXPrincipal</code>

 * may be associated with a particular <code>Subject</code>

 * to augment that <code>Subject</code> with an additional

 * identity.  Refer to the {@link javax.security.auth.Subject}

 * class for more information on how to achieve this.

 * Authorization decisions can then be based upon

 * the Principals associated with a <code>Subject</code>.

 *

 * @see java.security.Principal

 * @see javax.security.auth.Subject

 * @since 1.5

 */

public class JMXPrincipal implements Principal, Serializable {

    private static final long serialVersionUID = -4184480100214577411L;

    /**

     * @serial The JMX Remote API name for the identity represented by

     * this <code>JMXPrincipal</code> object.

     * @see #getName()

     */

    private String name;

    /**

     * Creates a JMXPrincipal for a given identity.

     *

     * @param name the JMX Remote API name for this identity.

     *

     * @exception NullPointerException if the <code>name</code> is

     * <code>null</code>.

     */

    public JMXPrincipal(String name) {

        validate(name);

        this.name = name;

    }

    /**

     * Returns the name of this principal.

     *

     * @return the name of this <code>JMXPrincipal</code>.

     */

    public String getName() {

        return name;

    }

    /**

     * Returns a string representation of this <code>JMXPrincipal</code>.

     *

     * @return a string representation of this <code>JMXPrincipal</code>.

     */

    public String toString() {

        return("JMXPrincipal:  " + name);

    }

    /**

     * Compares the specified Object with this <code>JMXPrincipal</code>

     * for equality.  Returns true if the given object is also a

     * <code>JMXPrincipal</code> and the two JMXPrincipals

     * have the same name.

     *

     * @param o Object to be compared for equality with this

     * <code>JMXPrincipal</code>.

     *

     * @return true if the specified Object is equal to this

     * <code>JMXPrincipal</code>.

     */

    public boolean equals(Object o) {

        if (o == null)

            return false;

        if (this == o)

            return true;

        if (!(o instanceof JMXPrincipal))

            return false;

        JMXPrincipal that = (JMXPrincipal)o;

        return (this.getName().equals(that.getName()));

    }

    /**

     * Returns a hash code for this <code>JMXPrincipal</code>.

     *

     * @return a hash code for this <code>JMXPrincipal</code>.

     */

    public int hashCode() {

        return name.hashCode();

    }

    private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {

        ObjectInputStream.GetField gf = ois.readFields();

        String principalName = (String)gf.get("name", null);

        try {

            validate(principalName);

            this.name = principalName;

        } catch (NullPointerException e) {

            throw new InvalidObjectException(e.getMessage());

        }

    }

    private static void validate(String name) throws NullPointerException {

        if (name == null)

            throw new NullPointerException("illegal null input");

    }

}