package com.cantaa.util.resource;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.text.MessageFormat;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;
import java.util.Locale;
import java.util.Properties;
import java.util.ResourceBundle;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.cantaa.util.Reject;
/**
* Handles loading resource-strings from a bundle
* <p/>
* Usage:
* <pre><code>
* provider = new BundleProvider("BundleName");
* String value = provider.getString("key", "parameter");
* </code></pre>
*
* @author Hans Lesmeister
*/
public class BundleProvider {
private static final Logger log = LoggerFactory.getLogger(BundleProvider.class);
private static final ResourceBundle.Control control = new MyBundleControl();
private static final List<String> CONTROL_FORMATS = Arrays.asList("properties.xml");
private final String[] bundleNames;
private LocaleProvider localeProvider;
/**
* Constructor for backwards compatibility
* @deprecated Use constructor <code>BundleProvider(LocalePricer, String[])</code> instead
* @param bundleName
* @param localeProvider
*/
public BundleProvider(String bundleName, LocaleProvider localeProvider) {
this(localeProvider, bundleName);
}
public BundleProvider(String bundleName) {
this(null, bundleName);
}
public BundleProvider(LocaleProvider localeProvider, String... bundleNames) {
super();
Reject.ifNull(bundleNames, "bundleNames is null");
Reject.ifTrue(bundleNames.length == 0, "bundleNames is empty");
this.bundleNames = bundleNames;
this.localeProvider = localeProvider;
}
public String getString(String key, Object... objects) {
return getString(null, key, objects);
}
public void setLocaleProvider(LocaleProvider localeProvider) {
this.localeProvider = localeProvider;
}
/**
* Get a localized resource string from the Bundle
*
* @param locale The locale to use. If null then locale from the locale provider is used or the current default locale is used
* @param key Key of the string in the bundle
* @param objects Optional array of values to feed MessageFormat for placeholders in the resource strings
* @return The value that was retrieved from the bundle. If the key could not be found then no exception is thrown. Instead,
* the key itself is returned
*/
public String getString(Locale locale, String key, Object... objects) {
Locale usedLocale = determineLocale(locale);
String value = key;
for (String bundleName : bundleNames) {
ResourceBundle rb = ResourceBundle.getBundle(bundleName, usedLocale, control);
if (rb.containsKey(key)) {
value = rb.getString(key);
break;
}
}
if ((value != null) && (objects != null) && (objects.length != 0)) {
final MessageFormat format = new MessageFormat(value, usedLocale);
value = format.format(objects);
}
return value;
}
/**
* Determine a locale to use
*
* @param locale
* @return the applied locale or, if null, the locale provided by the locale provider or, if null, the default locale
*/
private Locale determineLocale(Locale locale) {
if (locale != null) {
return locale;
}
if (localeProvider == null) {
return Locale.getDefault();
}
Locale usedLocale = localeProvider.getLocale();
if (usedLocale == null) {
return Locale.getDefault();
}
return usedLocale;
}
private static class MyBundleControl extends ResourceBundle.Control {
public List<String> getFormats(String baseName) {
if (baseName == null) {
throw new NullPointerException();
}
return CONTROL_FORMATS;
}
public ResourceBundle newBundle(String baseName,
Locale locale,
String format,
ClassLoader loader,
boolean reload)
throws IllegalAccessException,
InstantiationException,
IOException
{
if (baseName == null || locale == null
|| format == null || loader == null) {
throw new NullPointerException();
}
ResourceBundle bundle = null;
if (format.equals("properties.xml")) {
String bundleName = toBundleName(baseName, locale);
String resourceName = toResourceName(bundleName, format);
log.debug("bundleName to load: {}, resourceName to load {}", bundleName, resourceName);
InputStream stream = null;
if (reload) {
log.debug("Reloading the resource");
URL url = loader.getResource(resourceName);
if (url != null) {
URLConnection connection = url.openConnection();
if (connection != null) {
// Disable caches to get fresh data for
// reloading.
connection.setUseCaches(false);
stream = connection.getInputStream();
}
}
}
else {
log.debug("About to load the resource");
stream = loader.getResourceAsStream(resourceName);
}
if (stream != null) {
log.debug("Loading the resource");
BufferedInputStream bis = new BufferedInputStream(stream);
try {
bundle = new XMLResourceBundle(bis);
log.debug("Resource is loaded successfully");
}
finally {
bis.close();
}
}
}
return bundle;
}
}
private static class XMLResourceBundle extends ResourceBundle {
private Properties props;
XMLResourceBundle(InputStream stream) throws IOException {
props = new Properties();
props.loadFromXML(stream);
}
protected Object handleGetObject(String key) {
return props.getProperty(key);
}
@SuppressWarnings("unchecked")
public Enumeration<String> getKeys() {
return (Enumeration<String>) props.propertyNames();
}
}
}