Class ReloadableResourceBundleMessageSource
- All Implemented Interfaces:
Aware
,HierarchicalMessageSource
,MessageSource
,ResourceLoaderAware
MessageSource
implementation
that accesses resource bundles using specified basenames, participating in the
Spring ApplicationContext
's resource loading.
In contrast to the JDK-based ResourceBundleMessageSource
, this class uses
Properties
instances as its custom data structure for messages,
loading them via a PropertiesPersister
strategy
from Spring Resource
handles. This strategy is not only capable of
reloading files based on timestamp changes, but also of loading properties files
with a specific character encoding. It will detect XML property files as well.
Note that the basenames set as "basenames"
property
are treated in a slightly different fashion than the "basenames" property of
ResourceBundleMessageSource
. It follows the basic ResourceBundle rule of not
specifying file extension or language codes, but can refer to any Spring resource
location (instead of being restricted to classpath resources). With a "classpath:"
prefix, resources can still be loaded from the classpath, but "cacheSeconds" values
other than "-1" (caching forever) might not work reliably in this case.
For a typical web application, message files could be placed in WEB-INF
:
e.g. a "WEB-INF/messages" basename would find a "WEB-INF/messages.properties",
"WEB-INF/messages_en.properties" etc arrangement as well as "WEB-INF/messages.xml",
"WEB-INF/messages_en.xml" etc. Note that message definitions in a previous
resource bundle will override ones in a later bundle, due to sequential lookup.
This MessageSource can easily be used outside an
ApplicationContext
: it will use a
DefaultResourceLoader
as default,
simply getting overridden with the ApplicationContext's resource loader
if running in a context. It does not have any other specific dependencies.
Thanks to Thomas Achleitner for providing the initial implementation of this message source!
- Author:
- Juergen Hoeller, Sebastien Deleuze
- See Also:
-
AbstractResourceBasedMessageSource.setCacheSeconds(int)
AbstractResourceBasedMessageSource.setBasenames(java.lang.String...)
AbstractResourceBasedMessageSource.setDefaultEncoding(java.lang.String)
setFileEncodings(java.util.Properties)
setPropertiesPersister(org.springframework.util.PropertiesPersister)
setResourceLoader(org.springframework.core.io.ResourceLoader)
DefaultResourceLoader
ResourceBundleMessageSource
ResourceBundle
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprotected class
PropertiesHolder for caching. -
Field Summary
Fields inherited from class org.springframework.context.support.MessageSourceSupport
logger
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptioncalculateAllFilenames
(String basename, Locale locale) Calculate all filenames for the given bundle basename and Locale.calculateFilenamesForLocale
(String basename, Locale locale) Calculate the filenames for the given bundle basename and Locale, appending language code, country code, and variant code.void
Clear the resource bundle cache.void
Clear the resource bundle caches of this MessageSource and all its ancestors.getMergedProperties
(Locale locale) Get a PropertiesHolder that contains the actually visible properties for a Locale, after merging all specified resource bundles.getProperties
(String filename) Get a PropertiesHolder for the given filename, either from the cache or freshly loaded.protected Properties
loadProperties
(Resource resource, String filename) Load the properties from the given resource.protected Properties
Template method for creating a plain newProperties
instance.refreshProperties
(String filename, ReloadableResourceBundleMessageSource.PropertiesHolder propHolder) Refresh the PropertiesHolder for the given bundle filename.protected MessageFormat
resolveCode
(String code, Locale locale) Resolves the given message code as key in the retrieved bundle files, using a cached MessageFormat instance per message code.protected String
resolveCodeWithoutArguments
(String code, Locale locale) Resolves the given message code as key in the retrieved bundle files, returning the value found in the bundle as-is (without MessageFormat parsing).protected Resource
resolveResource
(String filename) Resolve the specified bundlefilename
into a concreteResource
, potentially checking multiple sources or file extensions.void
setConcurrentRefresh
(boolean concurrentRefresh) Specify whether to allow for concurrent refresh behavior, i.e.void
setFileEncodings
(Properties fileEncodings) Set per-file charsets to use for parsing properties files.void
setFileExtensions
(List<String> fileExtensions) Set the list of supported file extensions.void
setPropertiesPersister
(PropertiesPersister propertiesPersister) Set the PropertiesPersister to use for parsing properties files.void
setResourceLoader
(ResourceLoader resourceLoader) Set the ResourceLoader to use for loading bundle properties files.toString()
Methods inherited from class org.springframework.context.support.AbstractResourceBasedMessageSource
addBasenames, getBasenameSet, getCacheMillis, getDefaultEncoding, getDefaultLocale, isFallbackToSystemLocale, setBasename, setBasenames, setCacheMillis, setCacheSeconds, setDefaultEncoding, setDefaultLocale, setFallbackToSystemLocale
Methods inherited from class org.springframework.context.support.AbstractMessageSource
getCommonMessages, getDefaultMessage, getDefaultMessage, getMessage, getMessage, getMessage, getMessageFromParent, getMessageInternal, getParentMessageSource, isUseCodeAsDefaultMessage, resolveArguments, setCommonMessages, setParentMessageSource, setUseCodeAsDefaultMessage
Methods inherited from class org.springframework.context.support.MessageSourceSupport
createMessageFormat, formatMessage, isAlwaysUseMessageFormat, renderDefaultMessage, setAlwaysUseMessageFormat
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Constructor Details
-
ReloadableResourceBundleMessageSource
public ReloadableResourceBundleMessageSource()
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-
Method Details
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setFileExtensions
Set the list of supported file extensions.The default is a list containing
.properties
and.xml
.- Parameters:
fileExtensions
- the file extensions (starts with a dot)- Since:
- 6.1.0
-
setFileEncodings
Set per-file charsets to use for parsing properties files.Only applies to classic properties files, not to XML files.
- Parameters:
fileEncodings
- a Properties with filenames as keys and charset names as values. Filenames have to match the basename syntax, with optional locale-specific components: e.g. "WEB-INF/messages" or "WEB-INF/messages_en".- See Also:
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setConcurrentRefresh
public void setConcurrentRefresh(boolean concurrentRefresh) Specify whether to allow for concurrent refresh behavior, i.e. one thread locked in a refresh attempt for a specific cached properties file whereas other threads keep returning the old properties for the time being, until the refresh attempt has completed.Default is "true": this behavior is new as of Spring Framework 4.1, minimizing contention between threads. If you prefer the old behavior, i.e. to fully block on refresh, switch this flag to "false".
- Since:
- 4.1
- See Also:
-
setPropertiesPersister
Set the PropertiesPersister to use for parsing properties files.The default is
DefaultPropertiesPersister
.- See Also:
-
setResourceLoader
Set the ResourceLoader to use for loading bundle properties files.The default is a DefaultResourceLoader. Will get overridden by the ApplicationContext if running in a context, as it implements the ResourceLoaderAware interface. Can be manually overridden when running outside an ApplicationContext.
- Specified by:
setResourceLoader
in interfaceResourceLoaderAware
- Parameters:
resourceLoader
- the ResourceLoader object to be used by this object- See Also:
-
resolveCodeWithoutArguments
Resolves the given message code as key in the retrieved bundle files, returning the value found in the bundle as-is (without MessageFormat parsing).- Overrides:
resolveCodeWithoutArguments
in classAbstractMessageSource
- Parameters:
code
- the code of the message to resolvelocale
- the locale to resolve the code for (subclasses are encouraged to support internationalization)- Returns:
- the message String, or
null
if not found - See Also:
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resolveCode
Resolves the given message code as key in the retrieved bundle files, using a cached MessageFormat instance per message code.- Specified by:
resolveCode
in classAbstractMessageSource
- Parameters:
code
- the code of the message to resolvelocale
- 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:
-
getMergedProperties
Get a PropertiesHolder that contains the actually visible properties for a Locale, after merging all specified resource bundles. Either fetches the holder from the cache or freshly loads it.Only used when caching resource bundle contents forever, i.e. with cacheSeconds < 0. Therefore, merged properties are always cached forever.
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calculateAllFilenames
Calculate all filenames for the given bundle basename and Locale. Will calculate filenames for the given Locale, the system Locale (if applicable), and the default file.- Parameters:
basename
- the basename of the bundlelocale
- the locale- Returns:
- the List of filenames to check
- See Also:
-
calculateFilenamesForLocale
Calculate the filenames for the given bundle basename and Locale, appending language code, country code, and variant code.For example, basename "messages", Locale "de_AT_oo" → "messages_de_AT_OO", "messages_de_AT", "messages_de".
Follows the rules defined by
Locale.toString()
.- Parameters:
basename
- the basename of the bundlelocale
- the locale- Returns:
- the List of filenames to check
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getProperties
Get a PropertiesHolder for the given filename, either from the cache or freshly loaded.- Parameters:
filename
- the bundle filename (basename + Locale)- Returns:
- the current PropertiesHolder for the bundle
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refreshProperties
protected ReloadableResourceBundleMessageSource.PropertiesHolder refreshProperties(String filename, @Nullable ReloadableResourceBundleMessageSource.PropertiesHolder propHolder) Refresh the PropertiesHolder for the given bundle filename.The holder can be
null
if not cached before, or a timed-out cache entry (potentially getting re-validated against the current last-modified timestamp).- Parameters:
filename
- the bundle filename (basename + Locale)propHolder
- the current PropertiesHolder for the bundle- See Also:
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resolveResource
Resolve the specified bundlefilename
into a concreteResource
, potentially checking multiple sources or file extensions.If no suitable concrete
Resource
can be resolved, this method returns aResource
for whichResource.exists()
returnsfalse
, which gets subsequently ignored.This can be leveraged to check the last modification timestamp or to load properties from alternative sources — for example, from an XML BLOB in a database, or from properties serialized using a custom format such as JSON.
The default implementation delegates to the configured
ResourceLoader
to resolve resources, checking in order for existingResource
with extensions defined bysetFileExtensions(List)
(.properties
and.xml
by default).When overriding this method,
loadProperties(Resource, String)
must be capable of loading properties from any type ofResource
returned by this method. As a consequence, implementors are strongly encouraged to also overrideloadProperties()
.As an alternative to overriding this method, you can configure a
PropertiesPersister
that is capable of dealing with all resources returned by this method. Please note, however, that the defaultloadProperties()
implementation usesloadFromXml
for XML resources and otherwise uses the twoload
methods for other types of resources.- Parameters:
filename
- the bundle filename (basename + Locale)- Returns:
- the
Resource
to use - Since:
- 6.1
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loadProperties
Load the properties from the given resource.- Parameters:
resource
- the resource to load fromfilename
- the original bundle filename (basename + Locale)- Returns:
- the populated Properties instance
- Throws:
IOException
- if properties loading failed
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newProperties
Template method for creating a plain newProperties
instance. The default implementation simply callsProperties()
.Allows for returning a custom
Properties
extension in subclasses. Overriding methods should just instantiate a customProperties
subclass, with no further initialization or population to be performed at that point.- Returns:
- a plain Properties instance
- Since:
- 4.2
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clearCache
public void clearCache()Clear the resource bundle cache. Subsequent resolve calls will lead to reloading of the properties files. -
clearCacheIncludingAncestors
public void clearCacheIncludingAncestors()Clear the resource bundle caches of this MessageSource and all its ancestors.- See Also:
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toString
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