public class ReloadableResourceBundleMessageSource extends org.springframework.context.support.AbstractMessageSource implements org.springframework.context.ResourceLoaderAware
Spring-specific org.springframework.context.MessageSource implementation that accesses resource bundles using specified basenames, participating in the Spring org.springframework.context.ApplicationContext's resource loading.
In contrast to the JDK-based org.springframework.context.support.ResourceBundleMessageSource, this class uses java.util.Properties instances as its custom data structure for messages, loading them via a org.springframework.util.PropertiesPersister strategy from Spring org.springframework.core.io.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.
In contrast to org.springframework.context.support.ResourceBundleMessageSource, this class supports reloading of properties files through the "cacheSeconds" setting, and also through programmatically clearing the properties cache. Since application servers typically cache all files loaded from the classpath, it is necessary to store resources somewhere else (for example, in the "WEB-INF" directory of a web app). Otherwise changes of files in the classpath will not be reflected in the application.
Note that the base names set as "basenames" property are treated in a slightly different fashion than the "basenames" property of org.springframework.context.support.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) will not work in this case.
This MessageSource implementation is usually slightly faster than org.springframework.context.support.ResourceBundleMessageSource, which builds on java.util.ResourceBundle - in the default mode, i.e. when caching forever. With "cacheSeconds" set to 1, message lookup takes about twice as long - with the benefit that changes in individual properties files are detected with a maximum delay of 1 second. Higher "cacheSeconds" values usually do not make a significant difference.
This MessageSource can easily be used outside of an org.springframework.context.ApplicationContext: It will use a org.springframework.core.io.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!
| Modifiers | Name | Description |
|---|---|---|
protected class |
ReloadableResourceBundleMessageSource.PropertiesHolder |
PropertiesHolder for caching. |
protected static class |
ReloadableResourceBundleMessageSource.PropertiesHolderCacheEntry |
| Modifiers | Name | Description |
|---|---|---|
protected long |
cacheMillis |
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protected long |
fileCacheMillis |
| Type Params | Return Type | Name and description |
|---|---|---|
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protected java.util.List<Pair<java.lang.String, org.springframework.core.io.Resource>> |
calculateAllFilenames(java.lang.String basename, java.util.Locale locale)Calculate all filenames for the given bundle basename and Locale. |
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protected java.util.List<java.lang.String> |
calculateFilenamesForLocale(java.lang.String basename, java.util.Locale locale)Calculate the filenames for the given bundle basename and Locale, appending language code, country code, and variant code. |
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public ReloadableResourceBundleMessageSource.PropertiesHolder |
call() |
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public java.util.List<Pair<java.lang.String, org.springframework.core.io.Resource>> |
call() |
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public ReloadableResourceBundleMessageSource.PropertiesHolder |
call() |
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public CacheEntry |
call() |
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public org.springframework.core.io.Resource |
call() |
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public void |
clearCache()Clear the resource bundle cache. |
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public void |
clearCacheIncludingAncestors()Clear the resource bundle caches of this MessageSource and all its ancestors. |
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public java.util.Set<java.lang.String> |
getBundleCodes(java.util.Locale locale, java.lang.String basenames)Retrieves all codes from one or multiple basenames |
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protected ReloadableResourceBundleMessageSource.PropertiesHolder |
getMergedProperties(java.util.Locale locale)Get a PropertiesHolder that contains the actually visible properties for a Locale, after merging all specified resource bundles. |
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protected ReloadableResourceBundleMessageSource.PropertiesHolder |
getProperties(java.lang.String filename, org.springframework.core.io.Resource resource)Get a PropertiesHolder for the given filename, either from the cache or freshly loaded. |
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protected java.util.List<java.lang.String> |
getValidBasenames(java.lang.String[] basenames) |
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protected java.util.Properties |
loadProperties(org.springframework.core.io.Resource resource, java.lang.String filename)Load the properties from the given resource. |
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protected org.springframework.core.io.Resource |
locateResource(java.lang.String filename) |
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protected org.springframework.core.io.Resource |
locateResourceWithoutCache(java.lang.String filename) |
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protected java.text.MessageFormat |
resolveCode(java.lang.String code, java.util.Locale locale)Resolves the given message code as key in the retrieved bundle files, using a cached MessageFormat instance per message code. |
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protected java.lang.String |
resolveCodeWithoutArguments(java.lang.String code, java.util.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). |
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public void |
setBasename(java.lang.String basename)Set a single basename, following the basic ResourceBundle convention of not specifying file extension or language codes, but in contrast to org.springframework.context.support.ResourceBundleMessageSource referring to a Spring resource location: e.g. |
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public void |
setBasenames(java.lang.String basenames)Set an array of basenames, each following the basic ResourceBundle convention of not specifying file extension or language codes, but in contrast to org.springframework.context.support.ResourceBundleMessageSource referring to a Spring resource location: e.g. |
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public void |
setCacheSeconds(int cacheSeconds)Set the number of seconds to cache the list of matching properties files. |
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public void |
setDefaultEncoding(java.lang.String defaultEncoding)Set the default charset to use for parsing properties files. |
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public void |
setFallbackToSystemLocale(boolean fallbackToSystemLocale)Set whether to fall back to the system Locale if no files for a specific Locale have been found. |
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public void |
setFileCacheSeconds(int fileCacheSeconds)Set the number of seconds to cache loaded properties files. |
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public void |
setFileEncodings(java.util.Properties fileEncodings)Set per-file charsets to use for parsing properties files. |
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public void |
setPropertiesPersister(org.springframework.util.PropertiesPersister propertiesPersister)Set the PropertiesPersister to use for parsing properties files. |
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public void |
setResourceLoader(org.springframework.core.io.ResourceLoader resourceLoader)Set the ResourceLoader to use for loading bundle properties files. |
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public java.lang.String |
toString() |
| Methods inherited from class | Name |
|---|---|
class org.springframework.context.support.AbstractMessageSource |
org.springframework.context.support.AbstractMessageSource#getParentMessageSource(), org.springframework.context.support.AbstractMessageSource#setParentMessageSource(org.springframework.context.MessageSource), org.springframework.context.support.AbstractMessageSource#setCommonMessages(java.util.Properties), org.springframework.context.support.AbstractMessageSource#setUseCodeAsDefaultMessage(boolean), org.springframework.context.support.AbstractMessageSource#getMessage(java.lang.String, [Ljava.lang.Object;, java.util.Locale), org.springframework.context.support.AbstractMessageSource#getMessage(java.lang.String, [Ljava.lang.Object;, java.lang.String, java.util.Locale), org.springframework.context.support.AbstractMessageSource#getMessage(org.springframework.context.MessageSourceResolvable, java.util.Locale), org.springframework.context.support.AbstractMessageSource#setAlwaysUseMessageFormat(boolean), org.springframework.context.support.AbstractMessageSource#wait(long), org.springframework.context.support.AbstractMessageSource#wait(long, int), org.springframework.context.support.AbstractMessageSource#wait(), org.springframework.context.support.AbstractMessageSource#equals(java.lang.Object), org.springframework.context.support.AbstractMessageSource#toString(), org.springframework.context.support.AbstractMessageSource#hashCode(), org.springframework.context.support.AbstractMessageSource#getClass(), org.springframework.context.support.AbstractMessageSource#notify(), org.springframework.context.support.AbstractMessageSource#notifyAll() |
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.
basename - the basename of the bundlelocale - the localeCalculate the filenames for the given bundle basename and Locale, appending language code, country code, and variant code. E.g.: basename "messages", Locale "de_AT_oo" -> "messages_de_AT_OO", "messages_de_AT", "messages_de".
Follows the rules defined by java.util.Locale#toString().
basename - the basename of the bundlelocale - the localeClear the resource bundle cache. Subsequent resolve calls will lead to reloading of the properties files.
Clear the resource bundle caches of this MessageSource and all its ancestors.
Retrieves all codes from one or multiple basenames
locale - the localebasenames - the basenames of the bundleGet 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.
Get a PropertiesHolder for the given filename, either from the cache or freshly loaded.
filename - the bundle filename (basename + Locale)Load the properties from the given resource.
resource - the resource to load fromfilename - the original bundle filename (basename + Locale)Resolves the given message code as key in the retrieved bundle files, using a cached MessageFormat instance per message code.
Resolves the given message code as key in the retrieved bundle files, returning the value found in the bundle as-is (without MessageFormat parsing).
Set a single basename, following the basic ResourceBundle convention of not specifying file extension or language codes, but in contrast to org.springframework.context.support.ResourceBundleMessageSource referring to a Spring resource location: e.g. "WEB-INF/messages" for "WEB-INF/messages.properties", "WEB-INF/messages_en.properties", etc.
XML properties files are also supported: .g. "WEB-INF/messages" will find and load "WEB-INF/messages.xml", "WEB-INF/messages_en.xml", etc as well.
basename - the single basenameSet an array of basenames, each following the basic ResourceBundle convention of not specifying file extension or language codes, but in contrast to org.springframework.context.support.ResourceBundleMessageSource referring to a Spring resource location: e.g. "WEB-INF/messages" for "WEB-INF/messages.properties", "WEB-INF/messages_en.properties", etc.
XML properties files are also supported: .g. "WEB-INF/messages" will find and load "WEB-INF/messages.xml", "WEB-INF/messages_en.xml", etc as well.
The associated resource bundles will be checked sequentially when resolving a message code. Note that message definitions in a previous resource bundle will override ones in a later bundle, due to the sequential lookup.
basenames - an array of basenamesSet the number of seconds to cache the list of matching properties files.
java.util.ResourceBundle).
Set the default charset to use for parsing properties files. Used if no file-specific charset is specified for a file.
Default is none, using the java.util.Properties
default encoding: ISO-8859-1.
Only applies to classic properties files, not to XML files.
defaultEncoding - the default charsetSet whether to fall back to the system Locale if no files for a specific Locale have been found. Default is "true"; if this is turned off, the only fallback will be the default file (e.g. "messages.properties" for basename "messages").
Falling back to the system Locale is the default behavior of
java.util.ResourceBundle. However, this is often not desirable
in an application server environment, where the system Locale is not relevant
to the application at all: Set this flag to "false" in such a scenario.
Set the number of seconds to cache loaded properties files.
Set per-file charsets to use for parsing properties files.
Only applies to classic properties files, not to XML files.
fileEncodings - Properties with filenames as keys and charset
names as values. Filenames have to match the basename syntax,
with optional locale-specific appendices: e.g. "WEB-INF/messages"
or "WEB-INF/messages_en".Set the PropertiesPersister to use for parsing properties files.
The default is a DefaultPropertiesPersister.
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 of an ApplicationContext.