Class StrLookup.SystemPropertiesStrLookup

  • Enclosing class:
    StrLookup<V>

    private static class StrLookup.SystemPropertiesStrLookup
    extends StrLookup<java.lang.String>
    Lookup implementation based on system properties.
    • Constructor Detail

      • SystemPropertiesStrLookup

        private SystemPropertiesStrLookup()
    • Method Detail

      • lookup

        public java.lang.String lookup​(java.lang.String key)
        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.

        The StrLookup.lookup(String) 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", Integer.valueOf(2));
         assertEquals("2", StrLookup.mapLookup(map).lookup("number"));
         
        This implementation directly accesses system properties.
        Specified by:
        lookup in class StrLookup<java.lang.String>
        Parameters:
        key - the key to be looked up, may be null
        Returns:
        the matching value, null if no match