Zahlen in String durch Namen ersetzen

public class GroupFormattingModel extends FormattingTableModel {
        
        public static final SortedMap<String, Object> GROUPS = new TreeMap<String, Object>();
        static {
                GROUPS.put("1000", "Haus");
                GROUPS.put("1010", "Sonderartikel");
                GROUPS.put("1020", "Bestellwert");
        }
        
        public GroupFormattingModel () {
                super("GROUP");
        }
        
        private String groupNameToNumber(String group){
                String val = "";
                for(Map.Entry<String, Object> map : GROUPS.entrySet()){
                        if(map.getValue().equals(group)){
                                val = ""+map.getKey();
                                break;
                        }
                }
                return val;
        }
        
        private String groupNumberToName(String group){
                String val = (String)GROUPS.get(group);
                if(val == null) return "";
                return val;
        }
        
        public static List<String> groupStringAsList(String group){
                group = group.replaceAll("[\\{\\}]", "");
                List<String> groups = new ArrayList<String>(Arrays.asList(dgroup.split(",")));
                return groups;
        }
        
        public static String groupListAsString(List<String> groups){
                StringBuilder sb = new StringBuilder();
                boolean any = false;
                for(String s : groups){
                        if(any) sb.append(",");
                        sb.append(s);
                        any = true;
                }
                return sb.toString();
        }

        @Override
        protected String formatValueDownwards(String val) throws Exception {
                if(val.length() < 3) return "";
                
                List<String> groupsAsNames = groupStringAsList(val, ";");
                List<String> groupsAsNumbers = new ArrayList<String>();
                for(String s : groupsAsNames){
                        groupsAsNumbers.add(groupNameToNumber(s));
                }
                
                StringBuilder sb = new StringBuilder("{");
                sb.append(groupListAsString(groupsAsNumbers, ","));
                sb.append("}");
                return sb.toString();
        }

        @Override
        protected String formatValueUpwards(String val) throws Exception {
                if(val.length() < 3) return "";
                
                List<String> groupsAsNumbers = groupStringAsList(val, ",");
                List<String> groupsInNames = new ArrayList<String>();
                for(String s : groupsAsNumbers)
                        groupsInNames.add(groupNumberToName(s));
                
                StringBuilder sb = new StringBuilder("{");
                sb.append(groupListAsString(groupsInNames, ";"));
                sb.append("}");
                
                return sb.toString();
        }
}

public class Test {
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		test();
	}
	static void test()
	{
		String str = "{1000,2000,3000,4000}";
		String tmp;
		// Alles außerhalb der Klammern wird entfernt
		tmp = str.replaceAll(".*\\{","");
		tmp = tmp.replaceAll("\\}.*","");
		// String in einzelne Zahlenstrings zerteilen
		String[] num = tmp.split(",");
		int[] val = new int[num.length];
		// Zahlenstrings in int umwandeln
		int i = 0;
		for ( String s : num )
		{ val[i++] = new Integer(s); }
		// Testausgabe
		for ( int v : val )
		{ System.out.printf(">%d\n", v); }
	}
}

Ort               Person
------------      ------------
1 | Ahaus         A | Alice
2 | Berlin        B | Bob
3 | Chur          C | Charlie

OrtZuPerson
-----------
1 | A // die drei Adressen in Ahaus
1 | B
1 | C 
2 | A // die Berliner Adresse von Alice
3 | B // Bobs Adresse in seiner Ferienwohnung
3 | C // Charlies Adresse für seine Ferienwohnung