org.apache.wicket.request.resource.SharedResourceReference.java Source code

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Here is the source code for org.apache.wicket.request.resource.SharedResourceReference.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.request.resource;

import java.util.Locale;

import javax.servlet.http.HttpServletResponse;

import org.apache.wicket.Application;

/**
 * A {@link ResourceReference} which should be used to lookup a {@link IResource} from the globally
 * registered ones (also known as application shared resources). If there is no shared resource with
 * such {@link Key key} then it checks whether there is a {@link PackageResource} with this
 * {@link Key key} and registers it automatically if it exists.
 * <p>
 * Note: Cannot be registered in {@link ResourceReferenceRegistry} because
 * {@link SharedResourceReference} is just a shortcut to the {@link IResource resource} of another
 * {@link ResourceReference}
 */
public class SharedResourceReference extends ResourceReference {
    private static final long serialVersionUID = 1L;

    /**
     * Construct.
     * 
     * @param scope
     *            Scope of resource
     * @param name
     *            Logical name of resource
     * @param locale
     *            The locale of the resource
     * @param style
     *            The resource style (see {@link org.apache.wicket.Session})
     * @param variation
     *            The component specific variation of the style
     */
    public SharedResourceReference(Class<?> scope, String name, Locale locale, String style, String variation) {
        super(scope, name, locale, style, variation);
    }

    /**
     * Construct.
     * 
     * @param scope
     *            Scope of resource
     * @param name
     *            Logical name of resource
     */
    public SharedResourceReference(Class<?> scope, String name) {
        super(scope, name);
    }

    /**
     * Construct.
     * 
     * @param name
     *            resource name
     */
    public SharedResourceReference(String name) {
        super(name);
    }

    @Override
    public IResource getResource() {
        ResourceReference ref = Application.get().getResourceReferenceRegistry().getResourceReference(getScope(),
                getName(), getLocale(), getStyle(), getVariation(), false, true);

        if (ref == null) {
            return new AbstractResource() {
                private static final long serialVersionUID = 1L;

                @Override
                protected ResourceResponse newResourceResponse(Attributes attributes) {
                    ResourceResponse res = new ResourceResponse();
                    res.setError(HttpServletResponse.SC_NOT_FOUND);
                    return res;
                }
            };
        } else if (ref != this) {
            return ref.getResource();
        } else {
            throw new IllegalStateException(
                    "SharedResourceReference can not be registered globally. See the documentation of this class.");
        }
    }

    @Override
    public boolean canBeRegistered() {
        return false;
    }
}