Class StrLookup.SystemPropertiesStrLookup

java.lang.Object
org.apache.commons.lang3.text.StrLookup<String>
org.apache.commons.lang3.text.StrLookup.SystemPropertiesStrLookup
Enclosing class:
StrLookup<V>

private static final class StrLookup.SystemPropertiesStrLookup extends StrLookup<String>
Lookup implementation based on system properties.
  • Constructor Details

    • SystemPropertiesStrLookup

      private SystemPropertiesStrLookup()
  • Method Details

    • lookup

      public String lookup(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<String>
      Parameters:
      key - the key to be looked up, may be null
      Returns:
      the matching value, null if no match