Package com.aspectran.core.support.i18n.message

Class AbstractMessageSource

  • All Implemented Interfaces:
    HierarchicalMessageSource, MessageSource
    Direct Known Subclasses:
    ResourceBundleMessageSource
    public abstract class AbstractMessageSource
extends MessageSourceSupport
implements HierarchicalMessageSource

    This class is a clone of org.springframework.context.support.AbstractMessageSource

    Abstract implementation of the HierarchicalMessageSource interface, implementing common handling of message variants, making it easy to implement a specific strategy for a concrete MessageSource.

    Subclasses must implement the abstract resolveCode(java.lang.String, java.util.Locale) method. For efficient resolution of messages without arguments, the resolveCodeWithoutArguments(java.lang.String, java.util.Locale) method should be overridden as well, resolving messages without a MessageFormat being involved.

    Note: By default, message texts are only parsed through MessageFormat if arguments have been passed in for the message. In case of no arguments, message texts will be returned as-is. As a consequence, you should only use MessageFormat escaping for messages with actual arguments, and keep all other messages unescaped. If you prefer to escape all messages, set the "alwaysUseMessageFormat" flag to "true".

    Created: 2016. 2. 8.

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      protected java.util.Properties getCommonMessages()
      Return a Properties object defining locale-independent common messages, if any.
      protected java.lang.String getDefaultMessage​(java.lang.String code)
      Return a fallback default message for the given code, if any.
      java.lang.String getMessage​(java.lang.String code, java.lang.Object[] args, java.lang.String defaultMessage, java.util.Locale locale)
      Try to resolve the message.
      java.lang.String getMessage​(java.lang.String code, java.lang.Object[] args, java.util.Locale locale)
      Try to resolve the message.
      protected java.lang.String getMessageFromParent​(java.lang.String code, java.lang.Object[] args, java.util.Locale locale)
      Try to retrieve the given message from the parent MessageSource, if any.
      protected java.lang.String getMessageInternal​(java.lang.String code, java.lang.Object[] args, java.util.Locale locale)
      Resolve the given code and arguments as message in the given Locale, returning null if not found.
      MessageSource getParentMessageSource()
      Return the parent of this MessageSource, or null if none.
      protected boolean isUseCodeAsDefaultMessage()
      Return whether to use the message code as default message instead of throwing a NoSuchMessageException.
      protected abstract java.text.MessageFormat resolveCode​(java.lang.String code, java.util.Locale locale)
      Subclasses must implement this method to resolve a message.
      protected java.lang.String resolveCodeWithoutArguments​(java.lang.String code, java.util.Locale locale)
      Subclasses can override this method to resolve a message without arguments in an optimized fashion, i.e.
      void setCommonMessages​(java.util.Properties commonMessages)
      Specify locale-independent common messages, with the message code as key and the full message String (may contain argument placeholders) as value.
      void setParentMessageSource​(MessageSource parent)
      Set the parent that will be used to try to resolve messages that this object can't resolve.
      void setUseCodeAsDefaultMessage​(boolean useCodeAsDefaultMessage)
      Set whether to use the message code as default message instead of throwing a NoSuchMessageException.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • AbstractMessageSource

        public AbstractMessageSource()

    • Method Detail

      • setParentMessageSource

        public void setParentMessageSource​(MessageSource parent)
        Description copied from interface: HierarchicalMessageSource
        Set the parent that will be used to try to resolve messages that this object can't resolve.
        Specified by:
        setParentMessageSource in interface HierarchicalMessageSource
        Parameters:
        parent - the parent MessageSource that will be used to resolve messages that this object can't resolve. May be null, in which case no further resolution is possible.

      • setCommonMessages

        public void setCommonMessages​(java.util.Properties commonMessages)
        Specify locale-independent common messages, with the message code as key and the full message String (may contain argument placeholders) as value.
        Parameters:
        commonMessages - the common messages

      • getCommonMessages

        protected java.util.Properties getCommonMessages()
        Return a Properties object defining locale-independent common messages, if any.
        Returns:
        the common messages

      • setUseCodeAsDefaultMessage

        public void setUseCodeAsDefaultMessage​(boolean useCodeAsDefaultMessage)
        Set whether to use the message code as default message instead of throwing a NoSuchMessageException. Useful for development and debugging. Default is "false".

        Note: In case of a MessageSourceResolvable with multiple codes (like a FieldError) and a MessageSource that has a parent MessageSource, do not activate "useCodeAsDefaultMessage" in the parent: Else, you'll get the first code returned as message by the parent, without attempts to check further codes.

        To be able to work with "useCodeAsDefaultMessage" turned on in the parent, AbstractMessageSource and AbstractApplicationContext contain special checks to delegate to the internal getMessageInternal(java.lang.String, java.lang.Object[], java.util.Locale) method if available. In general, it is recommended to just use "useCodeAsDefaultMessage" during development and not rely on it in production in the first place, though.

        Parameters:
        useCodeAsDefaultMessage - whether use code as default message
        See Also:
        #getMessage(String, Object[], Locale)

      • isUseCodeAsDefaultMessage

        protected boolean isUseCodeAsDefaultMessage()
        Return whether to use the message code as default message instead of throwing a NoSuchMessageException. Useful for development and debugging. Default is "false".

        Alternatively, consider overriding the getDefaultMessage(java.lang.String) method to return a custom fallback message for an unresolvable code.

        Returns:
        whether use code as default message
        See Also:
        #getDefaultMessage(String)

      • getMessage

        public final java.lang.String getMessage​(java.lang.String code,
                                         java.lang.Object[] args,
                                         java.lang.String defaultMessage,
                                         java.util.Locale locale)
        Description copied from interface: MessageSource
        Try to resolve the message. Return default message if no message was found.
        Specified by:
        getMessage in interface MessageSource
        Parameters:
        code - the code to lookup up, such as 'calculator.noRateSet'. Users of this class are encouraged to base message names on the relevant fully qualified class name, thus avoiding conflict and ensuring maximum clarity.
        args - array of arguments that will be filled in for params within the message (params look like "{0}", "{1,date}", "{2,time}" within a message), or null if none.
        defaultMessage - String to return if the lookup fails
        locale - the Locale in which to do the lookup
        Returns:
        the resolved message if the lookup was successful; otherwise the default message passed as a parameter
        See Also:
        MessageFormat

      • getMessage

        public final java.lang.String getMessage​(java.lang.String code,
                                         java.lang.Object[] args,
                                         java.util.Locale locale)
                                  throws NoSuchMessageException
        Description copied from interface: MessageSource
        Try to resolve the message. Treat as an error if the message can't be found.
        Specified by:
        getMessage in interface MessageSource
        Parameters:
        code - the code to lookup up, such as 'calculator.noRateSet'
        args - Array of arguments that will be filled in for params within the message (params look like "{0}", "{1,date}", "{2,time}" within a message), or null if none.
        locale - the Locale in which to do the lookup
        Returns:
        the resolved message
        Throws:
        NoSuchMessageException - if the message wasn't found
        See Also:
        MessageFormat

      • getMessageInternal

        protected java.lang.String getMessageInternal​(java.lang.String code,
                                              java.lang.Object[] args,
                                              java.util.Locale locale)
        Resolve the given code and arguments as message in the given Locale, returning null if not found. Does not fall back to the code as default message. Invoked by getMessage methods.
        Parameters:
        code - the code to lookup up, such as 'calculator.noRateSet'
        args - array of arguments that will be filled in for params within the message
        locale - the Locale in which to do the lookup
        Returns:
        the resolved message, or null if not found
        See Also:
        #getMessage(String, Object[], String, Locale), #getMessage(String, Object[], Locale), #setUseCodeAsDefaultMessage

      • getMessageFromParent

        protected java.lang.String getMessageFromParent​(java.lang.String code,
                                                java.lang.Object[] args,
                                                java.util.Locale locale)
        Try to retrieve the given message from the parent MessageSource, if any.
        Parameters:
        code - the code to lookup up, such as 'calculator.noRateSet'
        args - array of arguments that will be filled in for params within the message
        locale - the Locale in which to do the lookup
        Returns:
        the resolved message, or null if not found
        See Also:
        #getParentMessageSource()

      • getDefaultMessage

        protected java.lang.String getDefaultMessage​(java.lang.String code)
        Return a fallback default message for the given code, if any.

        Default is to return the code itself if "useCodeAsDefaultMessage" is activated, or return no fallback else. In case of no fallback, the caller will usually receive a NoSuchMessageException from getMessage.

        Parameters:
        code - the message code that we couldn't resolve and that we didn't receive an explicit default message for
        Returns:
        the default message to use, or null if none
        See Also:
        #setUseCodeAsDefaultMessage

      • resolveCodeWithoutArguments

        protected java.lang.String resolveCodeWithoutArguments​(java.lang.String code,
                                                       java.util.Locale locale)
        Subclasses can override this method to resolve a message without arguments in an optimized fashion, i.e. to resolve without involving a MessageFormat.

        The default implementation does use MessageFormat, through delegating to the resolveCode(java.lang.String, java.util.Locale) method. Subclasses are encouraged to replace this with optimized resolution.

        Unfortunately, java.text.MessageFormat is not implemented in an efficient fashion. In particular, it does not detect that a message pattern doesn't contain argument placeholders in the first place. Therefore, it is advisable to circumvent MessageFormat for messages without arguments.

        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, MessageFormat

      • resolveCode

        protected abstract java.text.MessageFormat resolveCode​(java.lang.String code,
                                                       java.util.Locale locale)
        Subclasses must implement this method to resolve a message.

        Returns a MessageFormat instance rather than a message String, to allow for appropriate caching of MessageFormats in subclasses.

        Subclasses are encouraged to provide optimized resolution for messages without arguments, not involving MessageFormat. See the resolveCodeWithoutArguments(java.lang.String, java.util.Locale) javadoc for details.

        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:
        #resolveCodeWithoutArguments(String, java.util.Locale)