org.springframework.integration.expression
Class ReloadableResourceBundleExpressionSource

java.lang.Object
  extended by org.springframework.integration.expression.ReloadableResourceBundleExpressionSource
All Implemented Interfaces:
ResourceLoaderAware, ExpressionSource

public class ReloadableResourceBundleExpressionSource
extends java.lang.Object
implements ExpressionSource, ResourceLoaderAware

ExpressionSource implementation that accesses resource bundles using specified basenames. This class uses Properties instances as its custom data structure for expressions, loading them via a PropertiesPersister strategy: The default strategy is capable of loading properties files with a specific character encoding, if desired.

Since:
2.0
See Also:
setCacheSeconds(int), setBasenames(java.lang.String[]), setDefaultEncoding(java.lang.String), setFileEncodings(java.util.Properties), setPropertiesPersister(org.springframework.util.PropertiesPersister), setResourceLoader(org.springframework.core.io.ResourceLoader), DefaultPropertiesPersister, DefaultResourceLoader, ResourceBundle

Constructor Summary
ReloadableResourceBundleExpressionSource()
           
 
Method Summary
 void clearCache()
          Clear the resource bundle cache.
 Expression getExpression(java.lang.String key, java.util.Locale locale)
          Resolves the given key in the retrieved bundle files to an Expression.
 void setBasename(java.lang.String basename)
          Set a single basename, following the basic ResourceBundle convention of not specifying file extension or language codes, but referring to a Spring resource location: e.g.
 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 referring to a Spring resource location: e.g.
 void setCacheSeconds(int cacheSeconds)
          Set the number of seconds to cache loaded properties files.
 void setDefaultEncoding(java.lang.String defaultEncoding)
          Set the default charset to use for parsing properties files.
 void setFallbackToSystemLocale(boolean fallbackToSystemLocale)
          Set whether to fall back to the system Locale if no files for a specific Locale have been found.
 void setFileEncodings(java.util.Properties fileEncodings)
          Set per-file charsets to use for parsing properties files.
 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.
 java.lang.String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

ReloadableResourceBundleExpressionSource

public ReloadableResourceBundleExpressionSource()
Method Detail

setBasename

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 referring to a Spring resource location: e.g. "META-INF/expressions" for "META-INF/expressions.properties", "META-INF/expressions_en.properties", etc.

XML properties files are also supported: .g. "META-INF/expressions" will find and load "META-INF/expressions.xml", "META-INF/expressions_en.xml", etc as well.

Parameters:
basename - the single basename
See Also:
setBasenames(java.lang.String[]), ResourceEditor, ResourceBundle

setBasenames

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 referring to a Spring resource location: e.g. "META-INF/expressions" for "META-INF/expressions.properties", "META-INF/expressions_en.properties", etc.

XML properties files are also supported: .g. "META-INF/expressions" will find and load "META-INF/expressions.xml", "META-INF/expressions_en.xml", etc as well.

The associated resource bundles will be checked sequentially when resolving an expression key. Note that expression 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

setDefaultEncoding

public void setDefaultEncoding(java.lang.String defaultEncoding)
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.

Only applies to classic properties files, not to XML files.

Parameters:
defaultEncoding - the default charset
See Also:
setFileEncodings(java.util.Properties), PropertiesPersister.load(java.util.Properties, java.io.InputStream)

setFileEncodings

public void setFileEncodings(java.util.Properties fileEncodings)
Set per-file charsets to use for parsing properties files.

Only applies to classic properties files, not to XML files.

Parameters:
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. "META-INF/expressions" or "META-INF/expressions_en".
See Also:
setBasenames(java.lang.String[]), PropertiesPersister.load(java.util.Properties, java.io.InputStream)

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. "expressions.properties" for basename "expressions").

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.


setCacheSeconds

public void setCacheSeconds(int cacheSeconds)
Set the number of seconds to cache loaded properties files.


setPropertiesPersister

public void setPropertiesPersister(PropertiesPersister propertiesPersister)
Set the PropertiesPersister to use for parsing properties files.

The default is a DefaultPropertiesPersister.

See Also:
DefaultPropertiesPersister

setResourceLoader

public void setResourceLoader(ResourceLoader resourceLoader)
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.

Specified by:
setResourceLoader in interface ResourceLoaderAware
See Also:
DefaultResourceLoader, ResourceLoaderAware

getExpression

public Expression getExpression(java.lang.String key,
                                java.util.Locale locale)
Resolves the given key in the retrieved bundle files to an Expression.

Specified by:
getExpression in interface ExpressionSource

clearCache

public void clearCache()
Clear the resource bundle cache. Subsequent resolve calls will lead to reloading of the properties files.


toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object