Re: Class Struktur

From:
"John B. Matthews" <nospam@nospam.invalid>
Newsgroups:
comp.lang.java.programmer
Date:
Fri, 13 Nov 2009 10:51:03 -0500
Message-ID:
<nospam-0171B5.10510313112009@news.aioe.org>
In article <hdjq57$sds$1@news.albasani.net>,
 Stefan Meyer <devmanfrommars@gmx.de> wrote:

[...]

public class JConfigEntry { ... }

[...]

  public static HashMap<String, HashMap> data = new
    LinkedHashMap<String, HashMap>();

[...]

        JConfigEntry c = new JConfigEntry();

[...]

        data.put("sys", c);

[...]

i get alwys this error: cannot find symbol at this line

data.put("sys", c);

Whats wrong ?


Well, data is a HashMap<String, HashMap>, but you're trying to invoke
put with a String and a JConfigEntry. Perhaps you want the variable data
to be a Map <String, JConfigEntry>?

Here's a simple example of a the structure proposed by Joshua Cranmer in
an adjacent thread:

<code>
import java.util.HashMap;
import java.util.Map;

/**
 * @author John B. Matthews
 */
public class MapTest {

  public static void main(String[] args) {
    Map<String, Map<String, String>> map =
      new HashMap<String, Map<String, String>>();
    Map<String, String> m1 = new HashMap<String, String>();
    m1.put("One", "Alpha");
    m1.put("Two", "Beta");
    map.put("Ordinals", m1);
    Map<String, String> m2 = new HashMap<String, String>();
    m2.put("One", "Aleph");
    m2.put("Two", "Beth");
    map.put("Cardinals", m2);
    Map<String, String> m3 = new HashMap<String, String>();
    m3.put("One", "Alpher");
    m3.put("Two", "Bethe");
    map.put("Physicists", m3);
    printMap(map);
  }

  private static void printMap(Map<String, Map<String, String>> map) {
    for (Map.Entry entry : map.entrySet()) {
      System.out.println(entry.getKey() + " " + entry.getValue());
    }
    System.out.println();
  }
}
</code>

<console>
Ordinals {One=Alpha, Two=Beta}
Physicists {One=Alpher, Two=Bethe}
Cardinals {One=Aleph, Two=Beth}
</console>

--
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>

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