Class ReloadableResourceBundleExpressionSource

java.lang.Object
org.springframework.integration.expression.ReloadableResourceBundleExpressionSource
All Implemented Interfaces:
Aware, ResourceLoaderAware, ExpressionSource
public class ReloadableResourceBundleExpressionSource extends 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
Author:
Juergen Hoeller, Mark Fisher, Gary Russell, Artem Bilan, Christian Tzolov
See Also:

  • Constructor Details

    • ReloadableResourceBundleExpressionSource

      public ReloadableResourceBundleExpressionSource()

  • Method Details

    • setBasename

      public void setBasename(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

      public void setBasenames(@Nullable 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:

    • setDefaultEncoding

      public void setDefaultEncoding(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

      public void setFileEncodings(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:

    • 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.

      Parameters:
      fallbackToSystemLocale - true to fall back.

    • setCacheSeconds

      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 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 expression access. Do not use this in a production environment!
      Parameters:
      cacheSeconds - The cache seconds.

    • setPropertiesPersister

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

      The default is a DefaultPropertiesPersister.

      Parameters:
      propertiesPersister - The properties persister.
      See Also:

    • setResourceLoader

      public void setResourceLoader(@Nullable 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:

    • getExpression

      public Expression getExpression(String key, 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 String toString()
      Overrides:
      toString in class Object