common/src/main/java/flex/messaging/util/PropertyStringResourceLoader.java - flex-blazeds - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You 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 flex.messaging.util;

 import java.io.InputStream;
 import java.io.IOException;
 import java.text.MessageFormat;
 import java.util.Iterator;
 import java.util.Locale;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
 import java.util.TreeSet;

 import flex.messaging.log.Log;
 import flex.messaging.log.Logger;
 import flex.messaging.log.LogCategories;

 /**
  * Implementation of <code>ResourceLoader</code> that loads string resources
  * from property files.
  * <p>
  * This class uses <code>MessageFormat</code> to perform substitutions
  * within parameterized strings.
  * </p>
  *
  * @see MessageFormat
  *
  */
 public class PropertyStringResourceLoader implements ResourceLoader
 {
     // The property file bundle that contains localized error strings for BlazeDS.
     public static final String PROPERTY_BUNDLE = "flex/messaging/errors";

     // The property file bundle that contains localized error strings for BlazeDS
     // code specific to vendors (eg. LoginCommands for specific application serves)
     public static final String VENDORS_BUNDLE = "flex/messaging/vendors";

     // The property file bundle that contains localized error strings for LCDS.
     public static final String LCDS_PROPERTY_BUNDLE = "flex/data/errors";

     // The category to write log entries under.
     private static final String LOG_CATEGORY = LogCategories.RESOURCE;

     // The property bundle names to use in string lookups.
     private String[] propertyBundles;

     // The default FDS locale.
     private Locale defaultLocale;

     // The set of locales that have strings loaded.
     private Set loadedLocales = new TreeSet();

     // A map of all loaded strings.
     private Map strings = new HashMap();

     // The logger for this instance.
     private Logger logger;

     /**
      * Constructs a <code>PropertyStringResourceLoader</code> using the default
      * property bundles specified by the <code>PROPERTY_BUNDLE</code> and
      * <code>LCDS_PROPERTY_BUNDLE</code> fields.
      */
     public PropertyStringResourceLoader()
     {
         this(new String[] {PROPERTY_BUNDLE, LCDS_PROPERTY_BUNDLE});
     }

     /**
      * Constructs a <code>PropertyStringResourceLoader</code> that will use the
      * specified property bundle to use for string lookups.
      *
      * @param propertyBundle The property bundles to use for lookups.
      */
     public PropertyStringResourceLoader(String propertyBundle)
     {
         this(new String[] {propertyBundle});
     }

     /**
      * Constructs a <code>PropertyStringResourceLoader</code> that will use the
      * specified property bundles to use for string lookups.
      *
      * @param propertyBundles The list of the property bundles to use for lookups.
      */
     public PropertyStringResourceLoader(String[] propertyBundles)
     {
         this.propertyBundles = propertyBundles;
         logger = Log.getLogger(LOG_CATEGORY);
     }

     // Implements flex.messaging.util.ResourceLoader.init; inherits javadoc specification.
     public void init(Map properties)
     {}

     // Implements flex.messaging.util.ResourceLoader.getString; inherits javadoc specification.
     public String getString(String key)
     {
         return getString(key, null, null);
     }

     // Implements flex.messaging.util.ResourceLoader.getString; inherits javadoc specification.
     public String getString(String key, Object[] arguments)
     {
         return getString(key, null, arguments);
     }

     // Implements flex.messaging.util.ResourceLoader.getString; inherits javadoc specification.
     public String getString(String key, Locale locale)
     {
         return getString(key, locale, null);
     }

     // Implements flex.messaging.util.ResourceLoader.getString; inherits javadoc specification.
     public String getString(String key, Locale locale, Object[] arguments)
     {
         synchronized(strings)
         {
             if (defaultLocale == null)
             {
                 defaultLocale = getDefaultLocale();
             }
         }
         String value = null;
         String stringKey = null;
         String localeKey = (locale != null) ?
                            generateLocaleKey(locale) :
                            generateLocaleKey(defaultLocale);
         String originalStringKey = generateStringKey(key, localeKey);
         int trimIndex = 0;

         /*
          * Attempt to get a string for the target locale - fail back to less specific
          * versions of the locale.
          */
         while (true)
         {
             loadStrings(localeKey);
             stringKey = generateStringKey(key, localeKey);
             synchronized(strings)
             {
                 value = (String) strings.get(stringKey);
                 if (value != null)
                 {
                     if (!stringKey.equals(originalStringKey))
                     {
                         strings.put(originalStringKey, value);
                     }
                     return substituteArguments(value, arguments);
                 }
             }
             trimIndex = localeKey.lastIndexOf('_');
             if (trimIndex != -1)
             {
                 localeKey = localeKey.substring(0, trimIndex);
             }
             else
             {
                 break;
             }
         }

         /*
          * Attempt to get the string in our default locale if it is
          * different than the requested locale.
          */
         if ((locale != null) && (!locale.equals(defaultLocale)))
         {
             localeKey = generateLocaleKey(defaultLocale);
             stringKey = generateStringKey(key, localeKey);
             synchronized(strings)
             {
                 value = (String) strings.get(stringKey);
                 if (value != null)
                 {
                     strings.put(originalStringKey, value);
                     return substituteArguments(value, arguments);
                 }
             }
         }

         // As a last resort, try to get a non-locale-specific string.
         loadStrings("");
         stringKey = generateStringKey(key, "");
         synchronized(strings)
         {
             value = (String) strings.get(stringKey);
             if (value != null)
             {
                 strings.put(originalStringKey, value);
                 return substituteArguments(value, arguments);
             }
         }

         // No string is available. Return a formatted missing string value.
         return ("???" + key + "???");
     }

     /**
      * Sets the default locale to be used when locating resources. The
      * string will be converted into a Locale.
      *
      * @param locale The default locale to be used.
      */
     public void setDefaultLocale(String locale)
     {
         defaultLocale = LocaleUtils.buildLocale(locale);
     }

     /**
      * Sets the default locale to be used when locating resources.
      *
      * @param locale The default locale to be used.
      */
     public void setDefaultLocale(Locale locale)
     {
         defaultLocale = locale;
     }

     /**
      * The default locale to be used when locating resources.
      * @return Locale the default Locale object
      */
     public Locale getDefaultLocale()
     {
         if (defaultLocale == null)
             defaultLocale = Locale.getDefault();

         return defaultLocale;
     }

     /**
      * Loads localized strings for the specified locale from a property file.
      *
      * @param localeKey The locale to load strings for.
      */
     protected synchronized void loadStrings(String localeKey)
     {
         if (loadedLocales.contains(localeKey))
         {
             return;
         }

         if (propertyBundles != null)
         {
             for (int i = 0; i < propertyBundles.length; i++)
             {
                 String propertyBundle = propertyBundles[i];
                 loadProperties(localeKey, propertyBundle);
             }
         }
     }

     protected InputStream loadFile(String filename)
     {
         ClassLoader loader = Thread.currentThread().getContextClassLoader();
         InputStream stream = loader.getResourceAsStream(filename);

         // Try the properties file in our classloader too - just in case
         if (stream == null)
         {
             stream = PropertyStringResourceLoader.class.getClassLoader().getResourceAsStream(filename);
         }

         return stream;
     }

     // Helper method for loadStrings.
     protected void loadProperties(String localeKey, String propertyBundle)
     {
         // Build the path to the target property file.
         String filename = propertyBundle;
         if (localeKey.length() > 0)
         {
             filename += "_" + localeKey;
         }
         filename += ".properties";
         // Load the property file.
         InputStream stream = loadFile(filename);

         Properties props = new Properties();
         if (stream != null)
         {
             try
             {
                 props.load(stream);
             }
             catch (IOException ioe)
             {
                 logger.warn("There was a problem reading the string resource property file '" + filename + "' stream.", ioe);
             }
             catch (IllegalArgumentException iae)
             {
                 logger.warn("The string resource property file '" + filename + "' contains a malformed Unicode escape sequence.", iae);
             }
             finally
             {
                 try
                 {
                     stream.close();
                 }
                 catch (IOException ioe)
                 {
                     logger.warn("The string resource property file '" + filename + "' stream failed to close.", ioe);
                 }
             }
         }
         else
         {
             logger.warn("The class loader could not locate the string resource property file '" + filename + "'. This may not be an issue if a property file is available for a less specific locale or the default locale.");
         }
         // Move strings into string cache.
         if (props.size() > 0)
         {
             synchronized(strings)
             {
                 Iterator iter = props.keySet().iterator();
                 while (iter.hasNext())
                 {
                     String key = (String) iter.next();
                     strings.put(generateStringKey(key, localeKey), props.getProperty(key));
                 }
             }
         }
     }

     /**
      * Generates a locale cache key.
      *
      * @param locale The locale to generate a cache key for.
      * @return The generated cache key.
      */
     private String generateLocaleKey(Locale locale)
     {
         return (locale == null) ? "" : locale.toString();
     }

     /**
      * Generates a cache key for a string resource.
      *
      * @param key The string to generate a cache key for.
      * @param locale The locale to retrieve the string for.
      * @return The generated cache key for the string resource.
      */
     private String generateStringKey(String key, String locale)
     {
         return (key + "-" + locale);
     }

     /**
      * Substitutes the specified arguments into a parameterized string.
      *
      * @param parameterized The string containing parameter tokens for substitution.
      * @param arguments The arguments to substitute into the parameterized string.
      * @return The resulting substituted string.
      */
     private String substituteArguments(String parameterized, Object[] arguments)
     {
         return MessageFormat.format(parameterized, arguments).trim();
     }

 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You 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 flex.messaging.util;

	import java.io.InputStream;
	import java.io.IOException;
	import java.text.MessageFormat;
	import java.util.Iterator;
	import java.util.Locale;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Properties;
	import java.util.Set;
	import java.util.TreeSet;

	import flex.messaging.log.Log;
	import flex.messaging.log.Logger;
	import flex.messaging.log.LogCategories;

	/**
	* Implementation of <code>ResourceLoader</code> that loads string resources
	* from property files.
	* <p>
	* This class uses <code>MessageFormat</code> to perform substitutions
	* within parameterized strings.
	* </p>
	*
	* @see MessageFormat
	*
	*/
	public class PropertyStringResourceLoader implements ResourceLoader
	{
	// The property file bundle that contains localized error strings for BlazeDS.
	public static final String PROPERTY_BUNDLE = "flex/messaging/errors";

	// The property file bundle that contains localized error strings for BlazeDS
	// code specific to vendors (eg. LoginCommands for specific application serves)
	public static final String VENDORS_BUNDLE = "flex/messaging/vendors";

	// The property file bundle that contains localized error strings for LCDS.
	public static final String LCDS_PROPERTY_BUNDLE = "flex/data/errors";

	// The category to write log entries under.
	private static final String LOG_CATEGORY = LogCategories.RESOURCE;

	// The property bundle names to use in string lookups.
	private String[] propertyBundles;

	// The default FDS locale.
	private Locale defaultLocale;

	// The set of locales that have strings loaded.
	private Set loadedLocales = new TreeSet();

	// A map of all loaded strings.
	private Map strings = new HashMap();

	// The logger for this instance.
	private Logger logger;

	/**
	* Constructs a <code>PropertyStringResourceLoader</code> using the default
	* property bundles specified by the <code>PROPERTY_BUNDLE</code> and
	* <code>LCDS_PROPERTY_BUNDLE</code> fields.
	*/
	public PropertyStringResourceLoader()
	{
	this(new String[] {PROPERTY_BUNDLE, LCDS_PROPERTY_BUNDLE});
	}

	/**
	* Constructs a <code>PropertyStringResourceLoader</code> that will use the
	* specified property bundle to use for string lookups.
	*
	* @param propertyBundle The property bundles to use for lookups.
	*/
	public PropertyStringResourceLoader(String propertyBundle)
	{
	this(new String[] {propertyBundle});
	}

	/**
	* Constructs a <code>PropertyStringResourceLoader</code> that will use the
	* specified property bundles to use for string lookups.
	*
	* @param propertyBundles The list of the property bundles to use for lookups.
	*/
	public PropertyStringResourceLoader(String[] propertyBundles)
	{
	this.propertyBundles = propertyBundles;
	logger = Log.getLogger(LOG_CATEGORY);
	}

	// Implements flex.messaging.util.ResourceLoader.init; inherits javadoc specification.
	public void init(Map properties)
	{}

	// Implements flex.messaging.util.ResourceLoader.getString; inherits javadoc specification.
	public String getString(String key)
	{
	return getString(key, null, null);
	}

	// Implements flex.messaging.util.ResourceLoader.getString; inherits javadoc specification.
	public String getString(String key, Object[] arguments)
	{
	return getString(key, null, arguments);
	}

	// Implements flex.messaging.util.ResourceLoader.getString; inherits javadoc specification.
	public String getString(String key, Locale locale)
	{
	return getString(key, locale, null);
	}

	// Implements flex.messaging.util.ResourceLoader.getString; inherits javadoc specification.
	public String getString(String key, Locale locale, Object[] arguments)
	{
	synchronized(strings)
	{
	if (defaultLocale == null)
	{
	defaultLocale = getDefaultLocale();
	}
	}
	String value = null;
	String stringKey = null;
	String localeKey = (locale != null) ?
	generateLocaleKey(locale) :
	generateLocaleKey(defaultLocale);
	String originalStringKey = generateStringKey(key, localeKey);
	int trimIndex = 0;

	/*
	* Attempt to get a string for the target locale - fail back to less specific
	* versions of the locale.
	*/
	while (true)
	{
	loadStrings(localeKey);
	stringKey = generateStringKey(key, localeKey);
	synchronized(strings)
	{
	value = (String) strings.get(stringKey);
	if (value != null)
	{
	if (!stringKey.equals(originalStringKey))
	{
	strings.put(originalStringKey, value);
	}
	return substituteArguments(value, arguments);
	}
	}
	trimIndex = localeKey.lastIndexOf('_');
	if (trimIndex != -1)
	{
	localeKey = localeKey.substring(0, trimIndex);
	}
	else
	{
	break;
	}
	}

	/*
	* Attempt to get the string in our default locale if it is
	* different than the requested locale.
	*/
	if ((locale != null) && (!locale.equals(defaultLocale)))
	{
	localeKey = generateLocaleKey(defaultLocale);
	stringKey = generateStringKey(key, localeKey);
	synchronized(strings)
	{
	value = (String) strings.get(stringKey);
	if (value != null)
	{
	strings.put(originalStringKey, value);
	return substituteArguments(value, arguments);
	}
	}
	}

	// As a last resort, try to get a non-locale-specific string.
	loadStrings("");
	stringKey = generateStringKey(key, "");
	synchronized(strings)
	{
	value = (String) strings.get(stringKey);
	if (value != null)
	{
	strings.put(originalStringKey, value);
	return substituteArguments(value, arguments);
	}
	}

	// No string is available. Return a formatted missing string value.
	return ("???" + key + "???");
	}

	/**
	* Sets the default locale to be used when locating resources. The
	* string will be converted into a Locale.
	*
	* @param locale The default locale to be used.
	*/
	public void setDefaultLocale(String locale)
	{
	defaultLocale = LocaleUtils.buildLocale(locale);
	}

	/**
	* Sets the default locale to be used when locating resources.
	*
	* @param locale The default locale to be used.
	*/
	public void setDefaultLocale(Locale locale)
	{
	defaultLocale = locale;
	}

	/**
	* The default locale to be used when locating resources.
	* @return Locale the default Locale object
	*/
	public Locale getDefaultLocale()
	{
	if (defaultLocale == null)
	defaultLocale = Locale.getDefault();

	return defaultLocale;
	}

	/**
	* Loads localized strings for the specified locale from a property file.
	*
	* @param localeKey The locale to load strings for.
	*/
	protected synchronized void loadStrings(String localeKey)
	{
	if (loadedLocales.contains(localeKey))
	{
	return;
	}

	if (propertyBundles != null)
	{
	for (int i = 0; i < propertyBundles.length; i++)
	{
	String propertyBundle = propertyBundles[i];
	loadProperties(localeKey, propertyBundle);
	}
	}
	}

	protected InputStream loadFile(String filename)
	{
	ClassLoader loader = Thread.currentThread().getContextClassLoader();
	InputStream stream = loader.getResourceAsStream(filename);

	// Try the properties file in our classloader too - just in case
	if (stream == null)
	{
	stream = PropertyStringResourceLoader.class.getClassLoader().getResourceAsStream(filename);
	}

	return stream;
	}

	// Helper method for loadStrings.
	protected void loadProperties(String localeKey, String propertyBundle)
	{
	// Build the path to the target property file.
	String filename = propertyBundle;
	if (localeKey.length() > 0)
	{
	filename += "_" + localeKey;
	}
	filename += ".properties";
	// Load the property file.
	InputStream stream = loadFile(filename);

	Properties props = new Properties();
	if (stream != null)
	{
	try
	{
	props.load(stream);
	}
	catch (IOException ioe)
	{
	logger.warn("There was a problem reading the string resource property file '" + filename + "' stream.", ioe);
	}
	catch (IllegalArgumentException iae)
	{
	logger.warn("The string resource property file '" + filename + "' contains a malformed Unicode escape sequence.", iae);
	}
	finally
	{
	try
	{
	stream.close();
	}
	catch (IOException ioe)
	{
	logger.warn("The string resource property file '" + filename + "' stream failed to close.", ioe);
	}
	}
	}
	else
	{
	logger.warn("The class loader could not locate the string resource property file '" + filename + "'. This may not be an issue if a property file is available for a less specific locale or the default locale.");
	}
	// Move strings into string cache.
	if (props.size() > 0)
	{
	synchronized(strings)
	{
	Iterator iter = props.keySet().iterator();
	while (iter.hasNext())
	{
	String key = (String) iter.next();
	strings.put(generateStringKey(key, localeKey), props.getProperty(key));
	}
	}
	}
	}

	/**
	* Generates a locale cache key.
	*
	* @param locale The locale to generate a cache key for.
	* @return The generated cache key.
	*/
	private String generateLocaleKey(Locale locale)
	{
	return (locale == null) ? "" : locale.toString();
	}

	/**
	* Generates a cache key for a string resource.
	*
	* @param key The string to generate a cache key for.
	* @param locale The locale to retrieve the string for.
	* @return The generated cache key for the string resource.
	*/
	private String generateStringKey(String key, String locale)
	{
	return (key + "-" + locale);
	}

	/**
	* Substitutes the specified arguments into a parameterized string.
	*
	* @param parameterized The string containing parameter tokens for substitution.
	* @param arguments The arguments to substitute into the parameterized string.
	* @return The resulting substituted string.
	*/
	private String substituteArguments(String parameterized, Object[] arguments)
	{
	return MessageFormat.format(parameterized, arguments).trim();
	}

	}