path: root/dozentenmodul/src/main/java/org/openslx/dozmod/util/MapHelper.java

package org.openslx.dozmod.util;

import java.util.Map;
import java.util.Map.Entry;

import org.apache.log4j.Logger;

public class MapHelper {

	private static final Logger LOGGER = Logger.getLogger(MapHelper.class);

	private MapHelper() {
	}

	public static <T> boolean hasChanged(final Map<String, T> oldMap, final Map<String, T> newMap) {
		if (oldMap == null && newMap == null)
			return false;
		if ((oldMap == null && newMap != null) || (oldMap != null && newMap == null))
			return true;
		// build list of users that were added, if any return true
		if (oldMap.size() != newMap.size())
			return true;

		// no changes in the users, lets check for changes in each users permissions
		for (Entry<String, T> entry : oldMap.entrySet()) {
			T current = entry.getValue();
			T other = newMap.get(entry.getKey());
			if (!current.equals(other))
				return true;
		}
		// everything was the same if we are still here
		return false;
	}

}