multivaluemap.java

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    /**
     * 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)
     */
    public void putAll(Map map) {
        if (map instanceof MultiMap) {
            for (Iterator it = map.entrySet().iterator(); it.hasNext();) {
                Map.Entry entry = (Map.Entry) it.next();
                Collection coll = (Collection) entry.getValue();
                putAll(entry.getKey(), coll);
            }
        } else {
            for (Iterator it = map.entrySet().iterator(); it.hasNext();) {
                Map.Entry entry = (Map.Entry) it.next();
                put(entry.getKey(), entry.getValue());
            }
        }
    }

    /**
     * Gets a collection containing all the values in the map.
     * <p>
     * This returns a collection containing the combination of values from all keys.
     *
     * @return a collection view of the values contained in this map
     */
    public Collection values() {
        Collection vs = values;
        return (vs != null ? vs : (values = new Values()));
    }

    /**
     * Checks whether the collection at the specified key contains the value.
     *
     * @param value  the value to search for
     * @return true if the map contains the value
     */
    public boolean containsValue(Object key, Object value) {
        Collection coll = getCollection(key);
        if (coll == null) {
            return false;
        }
        return coll.contains(value);
    }

    /**
     * Gets the collection mapped to the specified key.
     * This method is a convenience method to typecast the result of <code>get(key)</code>.
     *
     * @param key  the key to retrieve
     * @return the collection mapped to the key, null if no mapping
     */
    public Collection getCollection(Object key) {
        return (Collection) getMap().get(key);
    }

    /**
     * Gets the size of the collection mapped to the specified key.
     *
     * @param key  the key to get size for
     * @return the size of the collection at the key, zero if key not in map
     */
    public int size(Object key) {
        Collection coll = getCollection(key);
        if (coll == null) {
            return 0;
        }
        return coll.size();
    }

    /**
     * Adds a collection of values to the collection associated with
     * the specified key.
     *
     * @param key  the key to store against
     * @param values  the values to add to the collection at the key, null ignored
     * @return true if this map changed
     */
    public boolean putAll(Object key, Collection values) {
        if (values == null || values.size() == 0) {
            return false;
        }
        Collection coll = getCollection(key);
        if (coll == null) {
            coll = createCollection(values.size());
            boolean result = coll.addAll(values);
            if (coll.size() > 0) {
                // only add if non-zero size to maintain class state
                getMap().put(key, coll);
                result = false;
            }
            return result;
        } else {
            return coll.addAll(values);
        }
    }

    /**
     * Gets an iterator for the collection mapped to the specified key.
     *
     * @param key  the key to get an iterator for
     * @return the iterator of the collection at the key, empty iterator if key not in map
     */
    public Iterator iterator(Object key) {
        if (!containsKey(key)) {
            return EmptyIterator.INSTANCE;
        } else {
            return new ValuesIterator(key);
        }
    }

    /**
     * Gets the total size of the map by counting all the values.
     *
     * @return the total size of the map counting all values
     */
    public int totalSize() {
        int total = 0;
        Collection values = getMap().values();
        for (Iterator it = values.iterator(); it.hasNext();) {
            Collection coll = (Collection) it.next();
            total += coll.size();
        }
        return total;
    }

    /**
     * Creates a new instance of the map value Collection container
     * using the factory.
     * <p>
     * This method can be overridden to perform your own processing
     * instead of using the factory.
     *
     * @param size  the collection size that is about to be added
     * @return the new collection
     */
    protected Collection createCollection(int size) {
        return (Collection) collectionFactory.create();
    }

    //-----------------------------------------------------------------------
    /**
     * Inner class that provides the values view.
     */
    private class Values extends AbstractCollection {
        public Iterator iterator() {
            final IteratorChain chain = new IteratorChain();
            for (Iterator it = keySet().iterator(); it.hasNext();) {
                chain.addIterator(new ValuesIterator(it.next()));
            }
            return chain;
        }

        public int size() {
            return totalSize();
        }

        public void clear() {
            MultiValueMap.this.clear();
        }
    }

    /**
     * Inner class that provides the values iterator.
     */
    private class ValuesIterator implements Iterator {
        private final Object key;
        private final Collection values;
        private final Iterator iterator;

        public ValuesIterator(Object key) {
            this.key = key;
            this.values = getCollection(key);
            this.iterator = values.iterator();
        }

        public void remove() {
            iterator.remove();
            if (values.isEmpty()) {
                MultiValueMap.this.remove(key);
            }
        }

        public boolean hasNext() {
            return iterator.hasNext();
        }

        public Object next() {
            return iterator.next();
        }
    }

    /**
     * Inner class that provides a simple reflection factory.
     */
    private static class ReflectionFactory implements Factory {
        private final Class clazz;

        public ReflectionFactory(Class clazz) {
            this.clazz = clazz;
        }

        public Object create() {
            try {
                return clazz.newInstance();
            } catch (Exception ex) {
                throw new FunctorException("Cannot instantiate class: " + clazz, ex);
            }
        }
    }

}