Module java.base
Package java.util

Class PropertyResourceBundle


  • public class PropertyResourceBundle
extends ResourceBundle
    PropertyResourceBundle is a concrete subclass of ResourceBundle that manages resources for a locale using a set of static strings from a property file. See ResourceBundle for more information about resource bundles.

    Unlike other types of resource bundle, you don't subclass PropertyResourceBundle. Instead, you supply properties files containing the resource data. ResourceBundle.getBundle will automatically look for the appropriate properties file and create a PropertyResourceBundle that refers to it. See ResourceBundle.getBundle for a complete description of the search and instantiation strategy.

    The following example shows a member of a resource bundle family with the base name "MyResources". The text defines the bundle "MyResources_de", the German member of the bundle family. This member is based on PropertyResourceBundle, and the text therefore is the content of the file "MyResources_de.properties" (a related example shows how you can add bundles to this family that are implemented as subclasses of ListResourceBundle). The keys in this example are of the form "s1" etc. The actual keys are entirely up to your choice, so long as they are the same as the keys you use in your program to retrieve the objects from the bundle. Keys are case-sensitive. 

     # MessageFormat pattern
 s1=Die Platte \"{1}\" enthält {0}.

 # location of {0} in pattern
 s2=1

 # sample disk name
 s3=Meine Platte

 # first ChoiceFormat choice
 s4=keine Dateien

 # second ChoiceFormat choice
 s5=eine Datei

 # third ChoiceFormat choice
 s6={0,number} Dateien

 # sample date
 s7=3. März 1996
    API Note:
    PropertyResourceBundle can be constructed either from an InputStream or a Reader, which represents a property file. Constructing a PropertyResourceBundle instance from an InputStream requires that the input stream be encoded in UTF-8. By default, if a MalformedInputException or an UnmappableCharacterException occurs on reading the input stream, then the PropertyResourceBundle instance resets to the state before the exception, re-reads the input stream in ISO-8859-1, and continues reading. If the system property java.util.PropertyResourceBundle.encoding is set to either "ISO-8859-1" or "UTF-8", the input stream is solely read in that encoding, and throws the exception if it encounters an invalid sequence. If "ISO-8859-1" is specified, characters that cannot be represented in ISO-8859-1 encoding must be represented by Unicode Escapes as defined in section 3.3 of The Java™ Language Specification whereas the other constructor which takes a Reader does not have that limitation. Other encoding values are ignored for this system property. The system property is read and evaluated when initializing this class. Changing or removing the property has no effect after the initialization.
    Implementation Requirements:
    The implementation of a PropertyResourceBundle subclass must be thread-safe if it's simultaneously used by multiple threads. The default implementations of the non-abstract methods in this class are thread-safe.
    Since:
    1.1
    See Also:
    ResourceBundle, ListResourceBundle, Properties

    • Constructor Detail

      • PropertyResourceBundle

        public PropertyResourceBundle​(InputStream stream)
                       throws IOException
        Creates a property resource bundle from an InputStream. This constructor reads the property file in UTF-8 by default. If a MalformedInputException or an UnmappableCharacterException occurs on reading the input stream, then the PropertyResourceBundle instance resets to the state before the exception, re-reads the input stream in ISO-8859-1 and continues reading. If the system property java.util.PropertyResourceBundle.encoding is set to either "ISO-8859-1" or "UTF-8", the input stream is solely read in that encoding, and throws the exception if it encounters an invalid sequence. Other encoding values are ignored for this system property. The system property is read and evaluated when initializing this class. Changing or removing the property has no effect after the initialization.
        Parameters:
        stream - an InputStream that represents a property file to read from.
        Throws:
        IOException - if an I/O error occurs
        NullPointerException - if stream is null
        IllegalArgumentException - if stream contains a malformed Unicode escape sequence.
        MalformedInputException - if the system property java.util.PropertyResourceBundle.encoding is set to "UTF-8" and stream contains an invalid UTF-8 byte sequence.
        UnmappableCharacterException - if the system property java.util.PropertyResourceBundle.encoding is set to "UTF-8" and stream contains an unmappable UTF-8 byte sequence.

    • Method Detail

      • handleGetObject

        public Object handleGetObject​(String key)
        Description copied from class: ResourceBundle
        Gets an object for the given key from this resource bundle. Returns null if this resource bundle does not contain an object for the given key.
        Specified by:
        handleGetObject in class ResourceBundle
        Parameters:
        key - the key for the desired object
        Returns:
        the object for the given key, or null

      • getKeys

        public Enumeration<String> getKeys​()
        Returns an Enumeration of the keys contained in this ResourceBundle and its parent bundles.
        Specified by:
        getKeys in class ResourceBundle
        Returns:
        an Enumeration of the keys contained in this ResourceBundle and its parent bundles.
        See Also:
        ResourceBundle.keySet()