/*
* Copyright 2002-2016 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.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.BeanClassLoaderAware;
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, BeanClassLoaderAware {
protected final Log logger = LogFactory.getLog(getClass());
private ThemeSource parentThemeSource;
private String basenamePrefix = "";
private String defaultEncoding;
private Boolean fallbackToSystemLocale;
private ClassLoader beanClassLoader;
/** Map from theme name to Theme instance */
private final Map<String, Theme> themeCache = new ConcurrentHashMap<>();
@Override
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) {
for (Theme theme : this.themeCache.values()) {
initParent(theme);
}
}
}
@Override
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 : "");
}
/**
* Set the default charset to use for parsing resource bundle files.
* <p>{@link ResourceBundleMessageSource}'s default is the
* {@code java.util.ResourceBundle} default encoding: ISO-8859-1.
* @since 4.2
* @see ResourceBundleMessageSource#setDefaultEncoding
*/
public void setDefaultEncoding(String defaultEncoding) {
this.defaultEncoding = defaultEncoding;
}
/**
* Set whether to fall back to the system Locale if no files for a
* specific Locale have been found.
* <p>{@link ResourceBundleMessageSource}'s default is "true".
* @since 4.2
* @see ResourceBundleMessageSource#setFallbackToSystemLocale
*/
public void setFallbackToSystemLocale(boolean fallbackToSystemLocale) {
this.fallbackToSystemLocale = fallbackToSystemLocale;
}
@Override
public void setBeanClassLoader(ClassLoader beanClassLoader) {
this.beanClassLoader = beanClassLoader;
}
/**
* 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
*/
@Override
public Theme getTheme(String themeName) {
if (themeName == null) {
return null;
}
Theme theme = this.themeCache.get(themeName);
if (theme == null) {
synchronized (this.themeCache) {
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);
if (this.defaultEncoding != null) {
messageSource.setDefaultEncoding(this.defaultEncoding);
}
if (this.fallbackToSystemLocale != null) {
messageSource.setFallbackToSystemLocale(this.fallbackToSystemLocale);
}
if (this.beanClassLoader != null) {
messageSource.setBeanClassLoader(this.beanClassLoader);
}
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());
}
}
}
}
}