/* * Copyright (c) 2008, 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 com.sun.beans.decoder; import java.beans.XMLDecoder; /** * This class is intended to handle &lt;java&gt; element. * Each element that appears in the body of this element * is evaluated in the context of the decoder itself. * Typically this outer context is used to retrieve the owner of the decoder, * which can be set before reading the archive. * <p>The following atributes are supported: * <dl> * <dt>version * <dd>the Java version (not supported) * <dt>class * <dd>the type of preferable parser (not supported) * <dt>id * <dd>the identifier of the variable that is intended to store the result * </dl> * * @see DocumentHandler#getOwner * @see DocumentHandler#setOwner * @since 1.7 * * @author Sergey A. Malenkov */final class JavaElementHandler extends ElementHandler {    private Class<?> type;    private ValueObject value;     /**     * Parses attributes of the element.     * The following atributes are supported:     * <dl>     * <dt>version     * <dd>the Java version (not supported)     * <dt>class     * <dd>the type of preferable parser (not supported)     * <dt>id     * <dd>the identifier of the variable that is intended to store the result     * </dl>     *     * @param name   the attribute name     * @param value  the attribute value     */    @Override    public void addAttribute(String name, String value) {        if (name.equals("version")) { // NON-NLS: the attribute name            // unsupported attribute        } else if (name.equals("class")) { // NON-NLS: the attribute name            // check class for owner            this.type = getOwner().findClass(value);        } else {            super.addAttribute(name, value);        }    }     /**     * Adds the argument to the list of readed objects.     *     * @param argument  the value of the element that contained in this one     */    @Override    protected void addArgument(Object argument) {        getOwner().addObject(argument);    }     /**     * Tests whether the value of this element can be used     * as an argument of the element that contained in this one.     *     * @return {@code true} if the value of this element should be used     *         as an argument of the element that contained in this one,     *         {@code false} otherwise     */    @Override    protected boolean isArgument() {        return false; // do not use owner as object    }     /**     * Returns the value of this element.     *     * @return the value of this element     */    @Override    protected ValueObject getValueObject() {        if (this.value == null) {            this.value = ValueObjectImpl.create(getValue());        }        return this.value;    }     /**     * Returns the owner of the owner document handler     * as a value of &lt;java&gt; element.     *     * @return the owner of the owner document handler     */    private Object getValue() {        Object owner = getOwner().getOwner();        if ((this.type == null) || isValid(owner)) {            return owner;        }        if (owner instanceof XMLDecoder) {            XMLDecoder decoder = (XMLDecoder) owner;            owner = decoder.getOwner();            if (isValid(owner)) {                return owner;            }        }        throw new IllegalStateException("Unexpected owner class: " + owner.getClass().getName());    }     /**     * Validates the owner of the &lt;java&gt; element.     * The owner is valid if it is {@code null} or an instance     * of the class specified by the {@code class} attribute.     *     * @param owner  the owner of the &lt;java&gt; element     * @return {@code true} if the {@code owner} is valid;     *         {@code false} otherwise     */    private boolean isValid(Object owner) {        return (owner == null) || this.type.isInstance(owner);    }}