How to use

entrySet

method

in

org.apache.commons.collections4.MultiMap

/**
 * Override superclass to ensure that MultiMap instances are
 * correctly handled.
 * <p>
 * If you call this method with a normal map, each entry is
 * added using <code>put(Object,Object)</code>.
 * If you call this method with a multi map, each entry is
 * added using <code>putAll(Object,Collection)</code>.
 *
 * @param map  the map to copy (either a normal or multi map)
 */
@Override
@SuppressWarnings("unchecked")
public void putAll(final Map<? extends K, ?> map) {
  if (map instanceof MultiMap) {
    for (final Map.Entry<? extends K, Object> entry : ((MultiMap<? extends K, V>) map).entrySet()) {
      putAll(entry.getKey(), (Collection<V>) entry.getValue());
    }
  } else {
    for (final Map.Entry<? extends K, ?> entry : map.entrySet()) {
      put(entry.getKey(), entry.getValue());
    }
  }
}

private void writeObject(ObjectOutputStream out) throws IOException {
  serializableHeadersBackingList = new HashMap();
  Iterator iter = headers.entrySet().iterator();
  while (iter.hasNext()) {
    Map.Entry entry = (Entry) iter.next();
    serializableHeadersBackingList.put(entry.getKey(), new ArrayList((Collection)entry.getValue()));
  }
  out.defaultWriteObject();
}