org.springframework.context.support

Class ResourceBundleMessageSource

java.lang.Object

org.springframework.context.support.MessageSourceSupport

org.springframework.context.support.AbstractMessageSource

org.springframework.context.support.ResourceBundleMessageSource

All Implemented Interfaces:

Aware, BeanClassLoaderAware, HierarchicalMessageSource, MessageSource

public class ResourceBundleMessageSource
extends AbstractMessageSource
implements 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.

Unfortunately, java.util.ResourceBundle caches loaded bundles forever: Reloading a bundle during VM execution is not possible. As this MessageSource relies on ResourceBundle, it faces the same limitation. Consider ReloadableResourceBundleMessageSource for an alternative that is capable of refreshing the underlying bundle files.

Author:

Rod Johnson, Juergen Hoeller

See Also:

setBasenames(java.lang.String...), ReloadableResourceBundleMessageSource, ResourceBundle, MessageFormat

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	ResourceBundleMessageSource.MessageSourceControl Custom implementation of Java 6's ResourceBundle.Control, adding support for custom file encodings, deactivating the fallback to the system locale and activating ResourceBundle's native cache, if desired.

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.String[]	basenames
private java.lang.ClassLoader	beanClassLoader
private java.lang.ClassLoader	bundleClassLoader
private java.util.Map<java.util.ResourceBundle,java.util.Map<java.lang.String,java.util.Map<java.util.Locale,java.text.MessageFormat>>>	cachedBundleMessageFormats Cache to hold already generated MessageFormats.
private java.util.Map<java.lang.String,java.util.Map<java.util.Locale,java.util.ResourceBundle>>	cachedResourceBundles Cache to hold loaded ResourceBundles.
private long	cacheMillis
private java.lang.String	defaultEncoding
private boolean	fallbackToSystemLocale

Fields inherited from class org.springframework.context.support.MessageSourceSupport

logger

Constructor Summary

Constructors

Constructor and Description
ResourceBundleMessageSource()

Method Summary

Modifier and Type	Method and Description
protected java.util.ResourceBundle	doGetBundle(java.lang.String basename, java.util.Locale locale) Obtain the resource bundle for the given basename and Locale.
protected java.lang.ClassLoader	getBundleClassLoader() Return the ClassLoader to load resource bundles with.
protected java.text.MessageFormat	getMessageFormat(java.util.ResourceBundle bundle, java.lang.String code, java.util.Locale locale) Return a MessageFormat for the given bundle and code, fetching already generated MessageFormats from the cache.
protected java.util.ResourceBundle	getResourceBundle(java.lang.String basename, java.util.Locale locale) Return a ResourceBundle for the given basename and code, fetching already generated MessageFormats from the cache.
private java.lang.String	getStringOrNull(java.util.ResourceBundle bundle, java.lang.String key)
protected java.util.ResourceBundle	loadBundle(java.io.Reader reader) Load a property-based resource bundle from the given reader.
protected java.text.MessageFormat	resolveCode(java.lang.String code, java.util.Locale locale) Resolves the given message code as key in the registered resource bundles, using a cached MessageFormat instance per message code.
protected java.lang.String	resolveCodeWithoutArguments(java.lang.String code, java.util.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).
void	setBasename(java.lang.String basename) Set a single basename, following ResourceBundle conventions: essentially, a fully-qualified classpath location.
void	setBasenames(java.lang.String... basenames) Set an array of basenames, each following ResourceBundle conventions: essentially, a fully-qualified classpath location.
void	setBeanClassLoader(java.lang.ClassLoader classLoader) Callback that supplies the bean class loader to a bean instance.
void	setBundleClassLoader(java.lang.ClassLoader classLoader) Set the ClassLoader to load resource bundles with.
void	setCacheSeconds(int cacheSeconds) Set the number of seconds to cache loaded resource bundle files.
void	setDefaultEncoding(java.lang.String defaultEncoding) Set the default charset to use for parsing resource bundle files.
void	setFallbackToSystemLocale(boolean fallbackToSystemLocale) Set whether to fall back to the system Locale if no files for a specific Locale have been found.
java.lang.String	toString() Show the configuration of this MessageSource.

Methods inherited from class org.springframework.context.support.AbstractMessageSource

getCommonMessages, 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

Methods inherited from class java.lang.Object

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

Field Detail

basenames

private java.lang.String[] basenames

defaultEncoding

private java.lang.String defaultEncoding

fallbackToSystemLocale

private boolean fallbackToSystemLocale

cacheMillis

private long cacheMillis

bundleClassLoader

private java.lang.ClassLoader bundleClassLoader

beanClassLoader

private java.lang.ClassLoader beanClassLoader

cachedResourceBundles

private final java.util.Map<java.lang.String,java.util.Map<java.util.Locale,java.util.ResourceBundle>> cachedResourceBundles

Cache to hold loaded ResourceBundles. This Map is keyed with the bundle basename, which holds a Map that is keyed with the Locale and in turn holds the ResourceBundle instances. This allows for very efficient hash lookups, significantly faster than the ResourceBundle class's own cache.

cachedBundleMessageFormats

private final java.util.Map<java.util.ResourceBundle,java.util.Map<java.lang.String,java.util.Map<java.util.Locale,java.text.MessageFormat>>> cachedBundleMessageFormats

Cache to hold already generated MessageFormats. This Map is keyed with the ResourceBundle, which holds a Map that is keyed with the message code, which in turn holds a Map that is keyed with the Locale and holds the MessageFormat values. This allows for very efficient hash lookups without concatenated keys.

See Also:

getMessageFormat(java.util.ResourceBundle, java.lang.String, java.util.Locale)

Constructor Detail

ResourceBundleMessageSource

public ResourceBundleMessageSource()

Method Detail

setBasename

public void setBasename(java.lang.String basename)

Set a single basename, following 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.

Messages will normally be held in the "/lib" or "/classes" directory of a web application's WAR structure. They can also be held in jar files on the class path.

Note that ResourceBundle names are effectively classpath locations: As a consequence, the JDK's standard ResourceBundle treats dots as package separators. This means that "test.theme" is effectively equivalent to "test/theme", just like it is for programmatic java.util.ResourceBundle usage.

See Also:

setBasenames(java.lang.String...), ResourceBundle.getBundle(String)

setBasenames

public void setBasenames(java.lang.String... basenames)

Set an array of basenames, each following 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.

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.

Note that ResourceBundle names are effectively classpath locations: As a consequence, the JDK's standard ResourceBundle treats dots as package separators. This means that "test.theme" is effectively equivalent to "test/theme", just like it is for programmatic java.util.ResourceBundle usage.

See Also:

setBasename(java.lang.String), ResourceBundle.getBundle(String)

setDefaultEncoding

public void setDefaultEncoding(java.lang.String defaultEncoding)

Set the default charset to use for parsing resource bundle files.

Default is the java.util.ResourceBundle default encoding: ISO-8859-1.

Since:

3.1.3

setFallbackToSystemLocale

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.

Since:

3.1.3

setCacheSeconds

public void setCacheSeconds(int cacheSeconds)

Set the number of seconds to cache loaded resource bundle files.

• Default is "-1", indicating to cache forever.
• A positive number will expire resource bundles after the given number of seconds. This is essentially the interval between refresh checks. 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!
• Note that depending on your ClassLoader, expiration might not work reliably since the ClassLoader may hold on to a cached version of the bundle file. Consider ReloadableResourceBundleMessageSource in combination with resource bundle files in a non-classpath location.

Since:

3.1.3

setBundleClassLoader

public void setBundleClassLoader(java.lang.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

protected java.lang.ClassLoader getBundleClassLoader()

Return the ClassLoader to load resource bundles with.

Default is the containing BeanFactory's bean ClassLoader.

See Also:

setBundleClassLoader(java.lang.ClassLoader)

setBeanClassLoader

public void setBeanClassLoader(java.lang.ClassLoader classLoader)

Description copied from interface: BeanClassLoaderAware

Callback that supplies the bean class loader to a bean instance.

Invoked after the population of normal bean properties but before an initialization callback such as InitializingBean's InitializingBean.afterPropertiesSet() method or a custom init-method.

Specified by:

setBeanClassLoader in interface BeanClassLoaderAware

Parameters:

classLoader - the owning class loader; may be null in which case a default ClassLoader must be used, for example the ClassLoader obtained via ClassUtils.getDefaultClassLoader()

resolveCodeWithoutArguments

protected java.lang.String resolveCodeWithoutArguments(java.lang.String code,
                                                       java.util.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:

AbstractMessageSource.resolveCode(java.lang.String, java.util.Locale), MessageFormat

resolveCode

protected java.text.MessageFormat resolveCode(java.lang.String code,
                                              java.util.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:

AbstractMessageSource.resolveCodeWithoutArguments(String, java.util.Locale)

getResourceBundle

protected java.util.ResourceBundle getResourceBundle(java.lang.String basename,
                                                     java.util.Locale locale)

Return a ResourceBundle for the given basename and code, fetching already generated MessageFormats 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 java.util.ResourceBundle doGetBundle(java.lang.String basename,
                                               java.util.Locale locale)
                                        throws java.util.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:

java.util.MissingResourceException - if no matching bundle could be found

See Also:

ResourceBundle.getBundle(String, Locale, ClassLoader), getBundleClassLoader()

loadBundle

protected java.util.ResourceBundle loadBundle(java.io.Reader reader)
                                       throws java.io.IOException

Load a property-based resource bundle from the given reader.

The default implementation returns a PropertyResourceBundle.

Parameters:

reader - the reader for the target resource

Returns:

the fully loaded bundle

Throws:

java.io.IOException - in case of I/O failure

Since:

4.2

See Also:

PropertyResourceBundle.PropertyResourceBundle(Reader)

getMessageFormat

protected java.text.MessageFormat getMessageFormat(java.util.ResourceBundle bundle,
                                                   java.lang.String code,
                                                   java.util.Locale locale)
                                            throws java.util.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:

java.util.MissingResourceException - if thrown by the ResourceBundle

getStringOrNull

private java.lang.String getStringOrNull(java.util.ResourceBundle bundle,
                                         java.lang.String key)

toString

public java.lang.String toString()

Show the configuration of this MessageSource.

Overrides:

toString in class java.lang.Object