/*
* Copyright 2002-2006 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.core.io.support;
import java.util.Locale;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.util.Assert;
/**
* Helper class for loading a localized resource,
* specified through name, extension and current locale.
*
* @author Juergen Hoeller
* @since 1.2.5
*/
public class LocalizedResourceHelper {
/** The default separator to use inbetween file name parts: an underscore */
public static final String DEFAULT_SEPARATOR = "_";
private final ResourceLoader resourceLoader;
private String separator = DEFAULT_SEPARATOR;
/**
* Create a new LocalizedResourceHelper with a DefaultResourceLoader.
* @see org.springframework.core.io.DefaultResourceLoader
*/
public LocalizedResourceHelper() {
this.resourceLoader = new DefaultResourceLoader();
}
/**
* Create a new LocalizedResourceHelper with the given ResourceLoader.
* @param resourceLoader the ResourceLoader to use
*/
public LocalizedResourceHelper(ResourceLoader resourceLoader) {
Assert.notNull(resourceLoader, "ResourceLoader must not be null");
this.resourceLoader = resourceLoader;
}
/**
* Set the separator to use inbetween file name parts.
* Default is an underscore ("_").
*/
public void setSeparator(String separator) {
this.separator = (separator != null ? separator : DEFAULT_SEPARATOR);
}
/**
* Find the most specific localized resource for the given name,
* extension and locale:
* <p>The file will be searched with locations in the following order,
* similar to <code>java.util.ResourceBundle</code>'s search order:
* <ul>
* <li>[name]_[language]_[country]_[variant][extension]
* <li>[name]_[language]_[country][extension]
* <li>[name]_[language][extension]
* <li>[name][extension]
* </ul>
* <p>If none of the specific files can be found, a resource
* descriptor for the default location will be returned.
* @param name the name of the file, without localization part nor extension
* @param extension the file extension (e.g. ".xls")
* @param locale the current locale (may be <code>null</code>)
* @return the most specific localized resource found
* @see java.util.ResourceBundle
*/
public Resource findLocalizedResource(String name, String extension, Locale locale) {
Assert.notNull(name, "Name must not be null");
Assert.notNull(extension, "Extension must not be null");
Resource resource = null;
if (locale != null) {
String lang = locale.getLanguage();
String country = locale.getCountry();
String variant = locale.getVariant();
// Check for file with language, country and variant localization.
if (variant.length() > 0) {
String location =
name + this.separator + lang + this.separator + country + this.separator + variant + extension;
resource = this.resourceLoader.getResource(location);
}
// Check for file with language and country localization.
if ((resource == null || !resource.exists()) && country.length() > 0) {
String location = name + this.separator + lang + this.separator + country + extension;
resource = this.resourceLoader.getResource(location);
}
// Check for document with language localization.
if ((resource == null || !resource.exists()) && lang.length() > 0) {
String location = name + this.separator + lang + extension;
resource = this.resourceLoader.getResource(location);
}
}
// Check for document without localization.
if (resource == null || !resource.exists()) {
String location = name + extension;
resource = this.resourceLoader.getResource(location);
}
return resource;
}
}
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