Re: Initializing a Map in an Interface?

From:
Kevin McMurtrie <mcmurtrie@pixelmemory.us>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 15 Mar 2010 22:10:23 -0700
Message-ID:
<4b9f12bf$0$22142$742ec2ed@news.sonic.net>
In article <Xns9D3C9E062BEC0noofflinecontactplea@202.177.16.121>,
 Rhino <no.offline.contact.please@example.com> wrote:

Is it possible to do a full-on assignment of specific values to a HashMap
in an interface? If so, how?

I'd like to create a HashMap that has a key that is a String and a value
that is a Color. The HashMap would contain a substantial number of these
entries.

I'm trying to figure out how to write the initialization but am confusing
myself with respect to brackets, braces, commas, etc.

Defining it as an Object[][] is easy enough:

        public static final Object[][] EIGHT_BIT_COLORS = {
            {"Black", new Color(0,0,0)},
            {"Obscure Gray", new Color(51, 51, 51)},
            {"Dark Gray", new Color(102, 102, 102)},
            {"Light Gray", new Color(153, 153, 153)},
            {"Pale Gray", new Color(204, 204, 204)},
            {"White", new Color(255, 255,255)}
        };

How could I write the definition if I want the Object[][] to be a HashMap
<String, Color>?

I'm guessing that defining the Map/HashMap explicitly like this isn't
possible and that I have to initialize it with code like this:

        Map<Color, String> colorsToNamesMap = new HashMap<Color,
String>();

        for (int ix=0; ix<EIGHT_BIT_COLORS.length; ix++) {
            colorsToNamesMap.put((Color)EIGHT_BIT_COLORS[ix][1],
(String)EIGHT_BIT_COLORS[ix][0]);
        }

which means I can't define the Map in an interface because this sort of
code can't appear in an Interface, only a Class.

Am I right about that?

--
Rhino

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---


Don't forget about the constructor for anonymous classes.

import java.awt.Color;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public interface FooColor
{
  public static final Map<String, Color> EIGHT_BIT_COLORS =
      Collections.unmodifiableMap(new HashMap<String, Color>()
  {
    {
      put("Black", new Color(0, 0, 0));
      put("Obscure Gray", new Color(51, 51, 51));
      put("Dark Gray", new Color(102, 102, 102));
      put("Light Gray", new Color(153, 153, 153));
      put("Pale Gray", new Color(204, 204, 204));
      put("White", new Color(255, 255, 255));
    }
  });
}
--
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