Class StrLookup<V>

  • Type Parameters:
    V - Unused.
    Direct Known Subclasses:
    StrLookup.MapStrLookup, StrLookup.SystemPropertiesStrLookup

    @Deprecated
    public abstract class StrLookup<V>
    extends java.lang.Object
    Deprecated.
    as of 3.6, use commons-text StringLookupFactory instead
    Lookup a String key to a String value.

    This class represents the simplest form of a string to string map. It has a benefit over a map in that it can create the result on demand based on the key.

    This class comes complete with various factory methods. If these do not suffice, you can subclass and implement your own matcher.

    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.

    Since:
    2.2
    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      (package private) static class  StrLookup.MapStrLookup<V>
      Deprecated.
      Lookup implementation that uses a Map.
      private static class  StrLookup.SystemPropertiesStrLookup
      Deprecated.
      Lookup implementation based on system properties.
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static StrLookup<java.lang.String> NONE_LOOKUP
      Deprecated.
      Lookup that always returns null.
      private static StrLookup<java.lang.String> SYSTEM_PROPERTIES_LOOKUP
      Deprecated.
      Lookup based on system properties.
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected StrLookup()
      Deprecated.
      Constructor.
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      abstract java.lang.String lookup​(java.lang.String key)
      Deprecated.
      Looks up a String key to a String value.
      static <V> StrLookup<V> mapLookup​(java.util.Map<java.lang.String,​V> map)
      Deprecated.
      Returns a lookup which looks up values using a map.
      static StrLookup<?> noneLookup()
      Deprecated.
      Returns a lookup which always returns null.
      static StrLookup<java.lang.String> systemPropertiesLookup()
      Deprecated.
      Returns a new lookup which uses a copy of the current System properties.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • NONE_LOOKUP

        private static final StrLookup<java.lang.String> NONE_LOOKUP
        Deprecated.
        Lookup that always returns null.
      • SYSTEM_PROPERTIES_LOOKUP

        private static final StrLookup<java.lang.String> SYSTEM_PROPERTIES_LOOKUP
        Deprecated.
        Lookup based on system properties.
    • Constructor Detail

      • StrLookup

        protected StrLookup()
        Deprecated.
        Constructor.
    • Method Detail

      • noneLookup

        public static StrLookup<?> noneLookup()
        Deprecated.
        Returns a lookup which always returns null.
        Returns:
        a lookup that always returns null, not null
      • systemPropertiesLookup

        public static StrLookup<java.lang.String> systemPropertiesLookup()
        Deprecated.
        Returns a new lookup which uses a copy of the current System properties.

        If a security manager blocked access to system properties, then null will be returned from every lookup.

        If a null key is used, this lookup will throw a NullPointerException.

        Returns:
        a lookup using system properties, not null
      • mapLookup

        public static <V> StrLookup<V> mapLookup​(java.util.Map<java.lang.String,​V> map)
        Deprecated.
        Returns a lookup which looks up values using a map.

        If the map is null, then null will be returned from every lookup. The map result object is converted to a string using toString().

        Type Parameters:
        V - the type of the values supported by the lookup
        Parameters:
        map - the map of keys to values, may be null
        Returns:
        a lookup using the map, not null
      • lookup

        public abstract java.lang.String lookup​(java.lang.String key)
        Deprecated.
        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 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"));
         
        Parameters:
        key - the key to be looked up, may be null
        Returns:
        the matching value, null if no match