EDIT

package eu.etaxonomy.cdm.vaadin.model;

import java.io.Serializable;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

public class User implements Serializable {

	/**

	 *

	 */

	private static final long serialVersionUID = 1L;

	private final String name;

	private final Map<String, String> prop;

	public User(String name) {

		this.name = name;

		prop = new HashMap<String, String>();

	}

	public void addProp(String column, String value) {

		prop.put(column, value);

	}

	public Collection<String> getPropertyId() {

		List<String> propertyId = new ArrayList<String>();

		for (Map.Entry<String, String> entry : prop.entrySet()) {

			propertyId.add(entry.getKey());

		}

		return propertyId;

	}

	public Collection<String> getItemId() {

		List<String> getItemId = new ArrayList<String>();

		for (Map.Entry<String, String> entry : prop.entrySet()) {

			getItemId.add(entry.getValue());

		}

		return getItemId;

	}

    /**

     * @param itemId

     */

    public Object getItem(Object itemId) {

        String item = itemId.toString();

        for (Map.Entry<String, String> entry : prop.entrySet()) {

            if(item.equalsIgnoreCase(entry.getValue())) {

                return entry.getValue();

            }

        }

        return null;

    }

    /**

     * @param itemId

     * @param propertyId

     */

    public Object getContainerProperty(Object itemId, Object propertyId) {

        if(prop.containsKey(propertyId) && prop.containsValue(itemId)){

            for (Map.Entry<String, String> entry : prop.entrySet()) {

                if(propertyId.toString().equalsIgnoreCase(entry.getKey())) {

                    return entry.getKey();

                }

            }

        }

        return null;

    }

}