Spring Framework example source code file (ResourceBundleThemeSource.java)

This example Spring Framework source code file (ResourceBundleThemeSource.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

hierarchicalmessagesource, hierarchicalmessagesource, hierarchicalthemesource, iterator, map, messagesource, resourcebundlemessagesource, simpletheme, string, string, theme, theme, themesource, themesource, util

The Spring Framework ResourceBundleThemeSource.java source code

/*
 * Copyright 2002-2007 the original author or authors.
 *
 * 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.springframework.ui.context.support;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.context.HierarchicalMessageSource;
import org.springframework.context.MessageSource;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.ui.context.HierarchicalThemeSource;
import org.springframework.ui.context.Theme;
import org.springframework.ui.context.ThemeSource;

/**
 * {@link ThemeSource} implementation that looks up an individual
 * {@link java.util.ResourceBundle} per theme. The theme name gets
 * interpreted as ResourceBundle basename, supporting a common
 * basename prefix for all themes.
 *
 * @author Jean-Pierre Pawlak
 * @author Juergen Hoeller
 * @see #setBasenamePrefix
 * @see java.util.ResourceBundle
 * @see org.springframework.context.support.ResourceBundleMessageSource
 */
public class ResourceBundleThemeSource implements HierarchicalThemeSource {

	protected final Log logger = LogFactory.getLog(getClass());

	private ThemeSource parentThemeSource;

	private String basenamePrefix = "";

	/** Map from theme name to Theme instance */
	private final Map themeCache = new HashMap();


	public void setParentThemeSource(ThemeSource parent) {
		this.parentThemeSource = parent;

		// Update existing Theme objects.
		// Usually there shouldn't be any at the time of this call.
		synchronized (this.themeCache) {
			Iterator it = this.themeCache.values().iterator();
			while (it.hasNext()) {
				initParent((Theme) it.next());
			}
		}
	}

	public ThemeSource getParentThemeSource() {
		return this.parentThemeSource;
	}

	/**
	 * Set the prefix that gets applied to the ResourceBundle basenames,
	 * i.e. the theme names.
	 * E.g.: basenamePrefix="test.", themeName="theme" -> basename="test.theme".
	 * <p>Note that ResourceBundle names are effectively classpath locations: As a
	 * consequence, the JDK's standard ResourceBundle treats dots as package separators.
	 * This means that "test.theme" is effectively equivalent to "test/theme",
	 * just like it is for programmatic <code>java.util.ResourceBundle usage.
	 * @see java.util.ResourceBundle#getBundle(String)
	 */
	public void setBasenamePrefix(String basenamePrefix) {
		this.basenamePrefix = (basenamePrefix != null ? basenamePrefix : "");
	}


	/**
	 * This implementation returns a SimpleTheme instance, holding a
	 * ResourceBundle-based MessageSource whose basename corresponds to
	 * the given theme name (prefixed by the configured "basenamePrefix").
	 * <p>SimpleTheme instances are cached per theme name. Use a reloadable
	 * MessageSource if themes should reflect changes to the underlying files.
	 * @see #setBasenamePrefix
	 * @see #createMessageSource
	 */
	public Theme getTheme(String themeName) {
		if (themeName == null) {
			return null;
		}
		synchronized (this.themeCache) {
			Theme theme = (Theme) this.themeCache.get(themeName);
			if (theme == null) {
				String basename = this.basenamePrefix + themeName;
				MessageSource messageSource = createMessageSource(basename);
				theme = new SimpleTheme(themeName, messageSource);
				initParent(theme);
				this.themeCache.put(themeName, theme);
				if (logger.isDebugEnabled()) {
					logger.debug("Theme created: name '" + themeName + "', basename [" + basename + "]");
				}
			}
			return theme;
		}
	}

	/**
	 * Create a MessageSource for the given basename,
	 * to be used as MessageSource for the corresponding theme.
	 * <p>Default implementation creates a ResourceBundleMessageSource.
	 * for the given basename. A subclass could create a specifically
	 * configured ReloadableResourceBundleMessageSource, for example.
	 * @param basename the basename to create a MessageSource for
	 * @return the MessageSource
	 * @see org.springframework.context.support.ResourceBundleMessageSource
	 * @see org.springframework.context.support.ReloadableResourceBundleMessageSource
	 */
	protected MessageSource createMessageSource(String basename) {
		ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
		messageSource.setBasename(basename);
		return messageSource;
	}

	/**
	 * Initialize the MessageSource of the given theme with the
	 * one from the corresponding parent of this ThemeSource.
	 * @param theme the Theme to (re-)initialize
	 */
	protected void initParent(Theme theme) {
		if (theme.getMessageSource() instanceof HierarchicalMessageSource) {
			HierarchicalMessageSource messageSource = (HierarchicalMessageSource) theme.getMessageSource();
			if (getParentThemeSource() != null && messageSource.getParentMessageSource() == null) {
				Theme parentTheme = getParentThemeSource().getTheme(theme.getName());
				if (parentTheme != null) {
					messageSource.setParentMessageSource(parentTheme.getMessageSource());
				}
			}
		}
	}

}