Enum PropertiesPlugin.NullLookup

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description
      INSTANCE  
    • Field Summary

      • Fields inherited from interface org.apache.logging.log4j.core.lookup.StrLookup

        CATEGORY
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private NullLookup()  
    • Constructor Detail

      • NullLookup

        private NullLookup()
    • Method Detail

      • values

        public static PropertiesPlugin.NullLookup[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
        for (PropertiesPlugin.NullLookup c : PropertiesPlugin.NullLookup.values())
            System.out.println(c);
        
        Returns:
        an array containing the constants of this enum type, in the order they are declared
      • valueOf

        public static PropertiesPlugin.NullLookup valueOf​(java.lang.String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        Parameters:
        name - the name of the enum constant to be returned.
        Returns:
        the enum constant with the specified name
        Throws:
        java.lang.IllegalArgumentException - if this enum type has no constant with the specified name
        java.lang.NullPointerException - if the argument is null
      • lookup

        public java.lang.String lookup​(java.lang.String key)
        Description copied from interface: StrLookup
        Looks up a String key to a String value.

        The internal implementation may use any mechanism to return the value. The simplest implementation is to use a Map. However, virtually any implementation is possible.

        For example, it would be possible to implement a lookup that used the key as a primary key, and looked up the value on demand from the database Or, a numeric based implementation could be created that treats the key as an integer, increments the value and return the result as a string - converting 1 to 2, 15 to 16 etc.

        This method always returns a String, regardless of the underlying data, by converting it as necessary. For example:

         Map<String, Object> map = new HashMap<String, Object>();
         map.put("number", new Integer(2));
         assertEquals("2", StrLookup.mapLookup(map).lookup("number"));
         
        Specified by:
        lookup in interface StrLookup
        Parameters:
        key - the key to be looked up, may be null
        Returns:
        the matching value, null if no match
      • lookup

        public java.lang.String lookup​(LogEvent event,
                                       java.lang.String key)
        Description copied from interface: StrLookup
        Looks up a String key to a String value possibly using the current LogEvent.

        The internal implementation may use any mechanism to return the value. The simplest implementation is to use a Map. However, virtually any implementation is possible.

        For example, it would be possible to implement a lookup that used the key as a primary key, and looked up the value on demand from the database Or, a numeric based implementation could be created that treats the key as an integer, increments the value and return the result as a string - converting 1 to 2, 15 to 16 etc.

        This method always returns a String, regardless of the underlying data, by converting it as necessary. For example:

         Map<String, Object> map = new HashMap<String, Object>();
         map.put("number", new Integer(2));
         assertEquals("2", StrLookup.mapLookup(map).lookup("number"));
         
        Specified by:
        lookup in interface StrLookup
        Parameters:
        event - The current LogEvent.
        key - the key to be looked up, may be null
        Returns:
        the matching value, null if no match