/*

 * Copyright (c) 2005, 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;

/**

 * This class is used by the query building mechanism for isInstanceOf expressions.

 * @serial include

 *

 * @since 1.6

 */

class InstanceOfQueryExp extends QueryEval implements QueryExp {

    /* Serial version */

    private static final long serialVersionUID = -1081892073854801359L;

    /**

     * @serial The {@link StringValueExp} returning the name of the class

     *         of which selected MBeans should be instances.

     */

    private StringValueExp classNameValue;

    /**

     * Creates a new InstanceOfExp with a specific class name.

     * @param classNameValue The {@link StringValueExp} returning the name of

     *        the class of which selected MBeans should be instances.

     */

    // We are using StringValueExp here to be consistent with other queries,

    // although we should actually either use a simple string (the classname)

    // or a ValueExp - which would allow more complex queries - like for

    // instance evaluating the class name from an AttributeValueExp.

    // As it stands - using StringValueExp instead of a simple constant string

    // doesn't serve any useful purpose besides offering a consistent

    // look & feel.

    public InstanceOfQueryExp(StringValueExp classNameValue) {

        if (classNameValue == null) {

            throw new IllegalArgumentException("Null class name.");

        }

        this.classNameValue = classNameValue;

    }

    /**

     * Returns the class name.

     * @returns The {@link StringValueExp} returning the name of

     *        the class of which selected MBeans should be instances.

     */

    public StringValueExp getClassNameValue()  {

        return classNameValue;

    }

    /**

     * Applies the InstanceOf on a MBean.

     *

     * @param name The name of the MBean on which the InstanceOf will be applied.

     *

     * @return  True if the MBean specified by the name is instance of the class.

     * @exception BadAttributeValueExpException

     * @exception InvalidApplicationException

     * @exception BadStringOperationException

     * @exception BadBinaryOpValueExpException

     */

    public boolean apply(ObjectName name)

        throws BadStringOperationException,

        BadBinaryOpValueExpException,

        BadAttributeValueExpException,

        InvalidApplicationException {

        // Get the class name value

        final StringValueExp val;

        try {

            val = (StringValueExp) classNameValue.apply(name);

        } catch (ClassCastException x) {

            // Should not happen - unless someone wrongly implemented

            // StringValueExp.apply().

            final BadStringOperationException y =

                    new BadStringOperationException(x.toString());

            y.initCause(x);

            throw y;

        }

        // Test whether the MBean is an instance of that class.

        try {

            return getMBeanServer().isInstanceOf(name, val.getValue());

        } catch (InstanceNotFoundException infe) {

            return false;

        }

    }

    /**

     * Returns a string representation of this InstanceOfQueryExp.

     * @return a string representation of this InstanceOfQueryExp.

     */

    public String toString() {

       return "InstanceOf " + classNameValue.toString();

   }

}