org.apache.tiles.request.collection.ReadOnlyEnumerationMap Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.tiles.request.collection;
import org.apache.tiles.request.attribute.HasKeys;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import static org.apache.tiles.request.collection.CollectionUtil.enumerationSize;
import static org.apache.tiles.request.collection.CollectionUtil.key;
/**
* Wraps an {@link HasKeys} object into a read-only map.
*
* @param The type of the values.
*/
public class ReadOnlyEnumerationMap implements Map {
/**
* The request.
*/
protected HasKeys request;
/**
* Constructor.
*
* @param request The request object to use.
*/
public ReadOnlyEnumerationMap(HasKeys request) {
this.request = request;
}
/**
* {@inheritDoc}
*/
public void clear() {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*/
public boolean containsKey(Object key) {
return (request.getValue(key(key)) != null);
}
/**
* {@inheritDoc}
*/
@SuppressWarnings("unchecked")
public boolean containsValue(Object value) {
V realValue = (V) value;
for (Enumeration keysIt = request.getKeys(); keysIt.hasMoreElements(); ) {
if (realValue.equals(request.getValue(keysIt.nextElement()))) {
return true;
}
}
return false;
}
/**
* {@inheritDoc}
*/
public Set> entrySet() {
return new ReadOnlyEnumerationMapEntrySet();
}
/**
* {@inheritDoc}
*/
public V get(Object key) {
return (request.getValue(key(key)));
}
/**
* {@inheritDoc}
*/
public boolean isEmpty() {
return !request.getKeys().hasMoreElements();
}
/**
* {@inheritDoc}
*/
public Set keySet() {
return new KeySet(request);
}
/**
* {@inheritDoc}
*/
public V put(String key, V value) {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*/
public void putAll(Map map) {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*/
public V remove(Object key) {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*/
public int size() {
return enumerationSize(request.getKeys());
}
/**
* {@inheritDoc}
*/
public Collection values() {
return new ReadOnlyEnumerationMapValuesCollection();
}
/**
* {@inheritDoc}
*/
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (!(obj instanceof ReadOnlyEnumerationMap)) {
return false;
}
@SuppressWarnings("unchecked")
HasKeys otherRequest = ((ReadOnlyEnumerationMap) obj).request;
boolean retValue = true;
Set otherKeys;
otherKeys = new HashSet<>();
for (Enumeration attribs = otherRequest.getKeys(); attribs.hasMoreElements(); ) {
otherKeys.add(attribs.nextElement());
}
for (Enumeration attribs = request.getKeys(); attribs.hasMoreElements() && retValue; ) {
String parameterName = attribs.nextElement();
retValue = request.getValue(parameterName).equals(otherRequest.getValue(parameterName));
otherKeys.remove(parameterName);
}
return retValue && otherKeys.isEmpty();
}
/**
* {@inheritDoc}
*/
@Override
public int hashCode() {
int retValue = 0;
for (Enumeration attribs = request.getKeys(); attribs
.hasMoreElements(); ) {
String parameterName = attribs.nextElement();
V value = request.getValue(parameterName);
retValue += parameterName.hashCode() ^ (value == null ? 0 : value.hashCode());
}
return retValue;
}
/**
* Entry set implementation for {@link ReadOnlyEnumerationMap}.
*/
class ReadOnlyEnumerationMapEntrySet implements Set> {
@Override
public boolean add(Entry e) {
throw new UnsupportedOperationException();
}
@Override
public boolean addAll(
Collection> c) {
throw new UnsupportedOperationException();
}
@Override
public void clear() {
throw new UnsupportedOperationException();
}
@SuppressWarnings("unchecked")
@Override
public boolean contains(Object o) {
return containsEntry((Entry) o);
}
@SuppressWarnings("unchecked")
@Override
public boolean containsAll(Collection c) {
Collection> realCollection =
(Collection>) c;
for (Entry entry : realCollection) {
if (!containsEntry(entry)) {
return false;
}
}
return true;
}
@Override
public boolean isEmpty() {
return ReadOnlyEnumerationMap.this.isEmpty();
}
@Override
public Iterator> iterator() {
return new ReadOnlyEnumerationMapEntrySetIterator();
}
@Override
public boolean remove(Object o) {
throw new UnsupportedOperationException();
}
@Override
public boolean removeAll(Collection c) {
throw new UnsupportedOperationException();
}
@Override
public boolean retainAll(Collection c) {
throw new UnsupportedOperationException();
}
@Override
public int size() {
return ReadOnlyEnumerationMap.this.size();
}
@Override
public Object[] toArray() {
return toList().toArray();
}
@Override
public T[] toArray(T[] a) {
return toList().toArray(a);
}
/**
* Checks whether the entry is present.
*
* @param entry The entry to check.
* @return true if the entry is present.
*/
protected boolean containsEntry(Entry entry) {
V storedValue = request.getValue(key(entry.getKey()));
return storedValue != null && storedValue.equals(entry.getValue());
}
/**
* Turns this set into a list.
*
* @return The list.
*/
private List> toList() {
List> entries = new ArrayList<>();
Enumeration names = request.getKeys();
while (names.hasMoreElements()) {
entries.add(extractNextEntry(names));
}
return entries;
}
/**
* Returns the next entry, given the enumeration.
*
* @param names The enumeration to get the next key from.
* @return The next entry.
*/
private MapEntry extractNextEntry(
Enumeration names) {
String name = names.nextElement();
return new MapEntry<>(name, request.getValue(name), false);
}
/**
* Iterates entries of {@link ReadOnlyEnumerationMap}.
*/
private class ReadOnlyEnumerationMapEntrySetIterator implements Iterator> {
/**
* Enumerates keys.
*/
private final Enumeration namesEnumeration = request.getKeys();
@Override
public boolean hasNext() {
return namesEnumeration.hasMoreElements();
}
@Override
public Entry next() {
if (namesEnumeration.hasMoreElements()) {
return extractNextEntry(namesEnumeration);
}
throw new NoSuchElementException();
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
}
/**
* Values collection for {@link ReadOnlyEnumerationMap}.
*/
private class ReadOnlyEnumerationMapValuesCollection implements Collection {
@Override
public boolean add(V e) {
throw new UnsupportedOperationException();
}
@Override
public boolean addAll(Collection c) {
throw new UnsupportedOperationException();
}
@Override
public void clear() {
throw new UnsupportedOperationException();
}
@Override
public boolean contains(Object o) {
return containsValue(o);
}
@SuppressWarnings("unchecked")
@Override
public boolean containsAll(Collection c) {
Collection realCollection = (Collection) c;
List valueList = new ArrayList<>(realCollection);
for (Enumeration keysEnum = request.getKeys(); keysEnum.hasMoreElements(); ) {
valueList.remove(request.getValue(keysEnum.nextElement()));
if (valueList.isEmpty()) {
return true;
}
}
return false;
}
@Override
public boolean isEmpty() {
return ReadOnlyEnumerationMap.this.isEmpty();
}
@Override
public Iterator iterator() {
return new ReadOnlyEnumerationMapValuesCollectionIterator();
}
@Override
public boolean remove(Object o) {
throw new UnsupportedOperationException();
}
@Override
public boolean removeAll(Collection c) {
throw new UnsupportedOperationException();
}
@Override
public boolean retainAll(Collection c) {
throw new UnsupportedOperationException();
}
@Override
public int size() {
return ReadOnlyEnumerationMap.this.size();
}
@Override
public Object[] toArray() {
return toList().toArray();
}
@Override
public T[] toArray(T[] a) {
return toList().toArray(a);
}
/**
* Turns this collection into a list.
*
* @return The list.
*/
private List toList() {
List entries = new ArrayList<>();
Enumeration names = request.getKeys();
while (names.hasMoreElements()) {
entries.add(request.getValue(names.nextElement()));
}
return entries;
}
/**
* Iterates values of {@link ReadOnlyEnumerationMap}.
*/
private class ReadOnlyEnumerationMapValuesCollectionIterator implements Iterator {
/**
* Enumerates attribute keys.
*/
private final Enumeration namesEnumeration = request.getKeys();
@Override
public boolean hasNext() {
return namesEnumeration.hasMoreElements();
}
@Override
public V next() {
if (namesEnumeration.hasMoreElements()) {
return request.getValue(namesEnumeration.nextElement());
}
throw new NoSuchElementException();
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
}
}