org.springframework.context.support
Class ReloadableResourceBundleMessageSource

org.springframework.context.support.AbstractNestingMessageSource
  |
  +--org.springframework.context.support.ReloadableResourceBundleMessageSource

public class ReloadableResourceBundleMessageSource

extends AbstractNestingMessageSource

implements ApplicationContextAware

MessageSource that accesses the ResourceBundles with the specified basenames. This class uses java.util.Properties instances as its internal data structure for messages.

In contrast to ResourceBundleMessageSoruce, this class supports reloading of properties files through the "cacheSeconds" setting, and also through programmatically clearing the properties cache. Since application servers do typcially 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 are not reflected in the application.

Note that the "basename" respectively "basenames" property has a different convention here: 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.

Author:

Thomas Achleitner, Juergen Hoeller

See Also: setCacheSeconds(int), setBasenames(java.lang.String[]), ResourceBundleMessageSource, ResourceBundle

Field Detail

PROPERTIES_SUFFIX

public final static String PROPERTIES_SUFFIX

public synchronized void clearCache()

Clear the resource bundle cache. Following resolve calls will lead to reloading of the properties files.

public void setApplicationContext(ApplicationContext context)

public void setBasename(String basename)

Set a single basename, following the basic ResourceBundle convention of not specifying file extension or language codes, but in contrast to ResourceBundleMessageSource referring to a Spring resource location: e.g. "WEB-INF/messages" for "WEB-INF/messages.properties", "WEB-INF/messages_en.properties", etc.

Parameters:

basename - the single basename

See Also:

setBasenames(java.lang.String[]), ResourceEditor, ResourceBundle

public void setBasenames(String[] basenames)

Set an array of basenames, each following the above-mentioned special convention. 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.

Parameters:

basenames - an array of basenames

See Also:

setBasename(java.lang.String), ResourceBundle

public void setCacheSeconds(int cacheSeconds)

Set the number of seconds to cache loaded properties files.

• Default is "-1", indicating to cache forever (just like java.util.ResourceBundle).
• A positive number will cache loaded properties files for the given number of seconds. This is essentially the interval between refresh attempts. Note that a refresh attempt will first check the last-modified timestamp of the file before actually reloading it; so if files don't change, this interval can be set rather low, as refresh attempts will not actually reload.
• A value of "0" will check the last-modified timestamp of the file on every message access. Do not use this in a production environment!

public void setFallbackToSystemLocale(boolean fallbackToSystemLocale)

Set 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.

public String toString()

Association Links

to Class java.lang.String

to Class org.springframework.context.ApplicationContext

to Class java.lang.String

to Class java.util.Map

Cache to hold filename lists per Locale

to Class java.util.Map

Cache to hold already loaded properties per filename