Class ResourceBundleMessageSource

All Implemented Interfaces:
org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanClassLoaderAware, HierarchicalMessageSource, MessageSource

public class ResourceBundleMessageSource extends AbstractResourceBasedMessageSource implements org.springframework.beans.factory.BeanClassLoaderAware
MessageSource implementation that accesses resource bundles using specified basenames. This class relies on the underlying JDK's ResourceBundle implementation, in combination with the JDK's standard message parsing provided by MessageFormat.

This MessageSource caches both the accessed ResourceBundle instances and the generated MessageFormats for each message. It also implements rendering of no-arg messages without MessageFormat, as supported by the AbstractMessageSource base class. The caching provided by this MessageSource is significantly faster than the built-in caching of the java.util.ResourceBundle class.

The basenames follow ResourceBundle conventions: essentially, a fully-qualified classpath location. If it doesn't contain a package qualifier (such as org.mypackage), it will be resolved from the classpath root. Note that the JDK's standard ResourceBundle treats dots as package separators: This means that "test.theme" is effectively equivalent to "test/theme".

On the classpath, bundle resources will be read with the locally configured encoding: by default, ISO-8859-1; consider switching this to UTF-8, or to null for the platform default encoding. On the JDK 9+ module path where locally provided ResourceBundle.Control handles are not supported, this MessageSource always falls back to ResourceBundle.getBundle(java.lang.String) retrieval with the platform default encoding: UTF-8 with a ISO-8859-1 fallback on JDK 9+ (configurable through the "java.util.PropertyResourceBundle.encoding" system property). Note that loadBundle(Reader)/loadBundle(InputStream) won't be called in this case either, effectively ignoring overrides in subclasses. Consider implementing a JDK 9 java.util.spi.ResourceBundleProvider instead.

Author:
Rod Johnson, Juergen Hoeller, Qimiao Chen
See Also:
  • Constructor Details

    • ResourceBundleMessageSource

      public ResourceBundleMessageSource()
  • Method Details

    • setBundleClassLoader

      public void setBundleClassLoader(ClassLoader classLoader)
      Set the ClassLoader to load resource bundles with.

      Default is the containing BeanFactory's bean ClassLoader, or the default ClassLoader determined by ClassUtils.getDefaultClassLoader() if not running within a BeanFactory.

    • getBundleClassLoader

      @Nullable protected ClassLoader getBundleClassLoader()
      Return the ClassLoader to load resource bundles with.

      Default is the containing BeanFactory's bean ClassLoader.

      See Also:
    • setBeanClassLoader

      public void setBeanClassLoader(ClassLoader classLoader)
      Specified by:
      setBeanClassLoader in interface org.springframework.beans.factory.BeanClassLoaderAware
    • resolveCodeWithoutArguments

      protected String resolveCodeWithoutArguments(String code, Locale locale)
      Resolves the given message code as key in the registered resource bundles, returning the value found in the bundle as-is (without MessageFormat parsing).
      Overrides:
      resolveCodeWithoutArguments in class AbstractMessageSource
      Parameters:
      code - the code of the message to resolve
      locale - the locale to resolve the code for (subclasses are encouraged to support internationalization)
      Returns:
      the message String, or null if not found
      See Also:
    • resolveCode

      @Nullable protected MessageFormat resolveCode(String code, Locale locale)
      Resolves the given message code as key in the registered resource bundles, using a cached MessageFormat instance per message code.
      Specified by:
      resolveCode in class AbstractMessageSource
      Parameters:
      code - the code of the message to resolve
      locale - the locale to resolve the code for (subclasses are encouraged to support internationalization)
      Returns:
      the MessageFormat for the message, or null if not found
      See Also:
    • getResourceBundle

      @Nullable protected ResourceBundle getResourceBundle(String basename, Locale locale)
      Return a ResourceBundle for the given basename and Locale, fetching already generated ResourceBundle from the cache.
      Parameters:
      basename - the basename of the ResourceBundle
      locale - the Locale to find the ResourceBundle for
      Returns:
      the resulting ResourceBundle, or null if none found for the given basename and Locale
    • doGetBundle

      protected ResourceBundle doGetBundle(String basename, Locale locale) throws MissingResourceException
      Obtain the resource bundle for the given basename and Locale.
      Parameters:
      basename - the basename to look for
      locale - the Locale to look for
      Returns:
      the corresponding ResourceBundle
      Throws:
      MissingResourceException - if no matching bundle could be found
      See Also:
    • loadBundle

      protected ResourceBundle loadBundle(Reader reader) throws IOException
      Load a property-based resource bundle from the given reader.

      This will be called in case of a "defaultEncoding", including ResourceBundleMessageSource's default ISO-8859-1 encoding. Note that this method can only be called with a ResourceBundle.Control: When running on the JDK 9+ module path where such control handles are not supported, any overrides in custom subclasses will effectively get ignored.

      The default implementation returns a PropertyResourceBundle.

      Parameters:
      reader - the reader for the target resource
      Returns:
      the fully loaded bundle
      Throws:
      IOException - in case of I/O failure
      Since:
      4.2
      See Also:
    • loadBundle

      protected ResourceBundle loadBundle(InputStream inputStream) throws IOException
      Load a property-based resource bundle from the given input stream, picking up the default properties encoding on JDK 9+.

      This will only be called with "defaultEncoding" set to null, explicitly enforcing the platform default encoding (which is UTF-8 with a ISO-8859-1 fallback on JDK 9+ but configurable through the "java.util.PropertyResourceBundle.encoding" system property). Note that this method can only be called with a ResourceBundle.Control: When running on the JDK 9+ module path where such control handles are not supported, any overrides in custom subclasses will effectively get ignored.

      The default implementation returns a PropertyResourceBundle.

      Parameters:
      inputStream - the input stream for the target resource
      Returns:
      the fully loaded bundle
      Throws:
      IOException - in case of I/O failure
      Since:
      5.1
      See Also:
    • getMessageFormat

      @Nullable protected MessageFormat getMessageFormat(ResourceBundle bundle, String code, Locale locale) throws MissingResourceException
      Return a MessageFormat for the given bundle and code, fetching already generated MessageFormats from the cache.
      Parameters:
      bundle - the ResourceBundle to work on
      code - the message code to retrieve
      locale - the Locale to use to build the MessageFormat
      Returns:
      the resulting MessageFormat, or null if no message defined for the given code
      Throws:
      MissingResourceException - if thrown by the ResourceBundle
    • getStringOrNull

      @Nullable protected String getStringOrNull(ResourceBundle bundle, String key)
      Efficiently retrieve the String value for the specified key, or return null if not found.

      As of 4.2, the default implementation checks containsKey before it attempts to call getString (which would require catching MissingResourceException for key not found).

      Can be overridden in subclasses.

      Parameters:
      bundle - the ResourceBundle to perform the lookup in
      key - the key to look up
      Returns:
      the associated value, or null if none
      Since:
      4.2
      See Also:
    • toString

      public String toString()
      Show the configuration of this MessageSource.
      Overrides:
      toString in class Object