org.wicketstuff.springreference.SpringReferenceSupporter.java Source code

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Here is the source code for org.wicketstuff.springreference.SpringReferenceSupporter.java

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/*
 * Licensed 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.wicketstuff.springreference;

import javax.servlet.ServletContext;

import org.apache.wicket.Application;
import org.apache.wicket.MetaDataKey;
import org.apache.wicket.protocol.http.WebApplication;
import org.apache.wicket.util.lang.Args;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

/**
 * <p>
 * Used by {@link SpringReference} and {@link AbstractSpringDependencies} to do the actual spring
 * bean lookups. This must be registered in the init() method of your wicket {@link Application} or
 * {@link WebApplication} otherwise {@link SpringReference} and {@link AbstractSpringDependencies}
 * will not work.
 * </p>
 * <p>
 * Example:
 * 
 * <pre>
 * <code>
 *  public class App extends WebApplication {
 *    &#64;Override
 *    public Class<? extends Page> getHomePage() {
 *       return HomePage.class;
 *    }
 * 
 *    &#64;Override
 *    protected void init() {
 *       super.init();
 * 
 *       getMarkupSettings().setDefaultMarkupEncoding(CharEncoding.UTF_8);
 * 
 *       <b>SpringReferenceSupporter.register(this);</b> // <--
 *    }
 * }
 * </code>
 * </pre>
 * 
 * </p>
 * 
 * @author akiraly
 * 
 */
public class SpringReferenceSupporter extends AbstractSpringReferenceSupporter {

    private static MetaDataKey<SpringReferenceSupporter> LOCATOR_KEY = new MetaDataKey<SpringReferenceSupporter>() {
        private static final long serialVersionUID = 5075847072788088007L;
    };

    private final ApplicationContext applicationContext;

    /**
     * Constructor.
     * 
     * @param applicationContext
     *            where the spring bean will be searched for, not null
     */
    public SpringReferenceSupporter(ApplicationContext applicationContext) {
        Args.notNull(applicationContext, "applicationContext");

        this.applicationContext = applicationContext;
    }

    /**
     * Creates and registers an instance of this class with the wicket web application. Uses
     * {@link WebApplicationContextUtils#getRequiredWebApplicationContext(ServletContext)} to get
     * spring web application context. If more fine grained registration is needed use
     * {@link #register(Application, SpringReferenceSupporter)}. If you want to use
     * {@link SpringReference} you have to use one of the register methods in your wicket
     * applications init().
     * 
     * @param application
     *            wicket web application, not null
     */
    public static void register(WebApplication application) {
        Args.notNull(application, "application");

        ServletContext servletContext = application.getServletContext();
        WebApplicationContext applicationContext = WebApplicationContextUtils
                .getRequiredWebApplicationContext(servletContext);
        register(application, new SpringReferenceSupporter(applicationContext));
    }

    /**
     * Registers the passed in supporter with the wicket application. This is the more sophisticated
     * variant of registration. Most users could go with {@link #register(WebApplication)}.
     * 
     * @param application
     *            wicket application, not null
     * @param supporter
     *            spring reference supporter. Null value means removal.
     */
    public static void register(Application application, SpringReferenceSupporter supporter) {
        Args.notNull(application, "application");

        application.setMetaData(LOCATOR_KEY, supporter);
    }

    /**
     * @return instance registered with the current threads wicket application
     */
    protected static SpringReferenceSupporter get() {
        return Application.get().getMetaData(LOCATOR_KEY);
    }

    @Override
    protected ApplicationContext getApplicationContext() {
        return applicationContext;
    }
}