/*
 * Copyright (c) 2021 Goldman Sachs.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v. 1.0 which accompany this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */

package org.eclipse.collections.impl;

import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.Set;

An unmodifiable view of a Map.
/** * An unmodifiable view of a Map. */
public class UnmodifiableMap<K, V> implements Map<K, V>, Serializable { private static final long serialVersionUID = 1L; protected final Map<K, V> delegate; public UnmodifiableMap(Map<K, V> delegate) { if (delegate == null) { throw new NullPointerException(); } this.delegate = delegate; } @Override public int size() { return this.delegate.size(); } @Override public boolean isEmpty() { return this.delegate.isEmpty(); } @Override public boolean containsKey(Object key) { return this.delegate.containsKey(key); } @Override public boolean containsValue(Object value) { return this.delegate.containsValue(value); } @Override public V get(Object key) { return this.delegate.get(key); } @Override public V put(K key, V value) { throw new UnsupportedOperationException("Cannot call put() on " + this.getClass().getSimpleName()); } @Override public V remove(Object key) { throw new UnsupportedOperationException("Cannot call remove() on " + this.getClass().getSimpleName()); } @Override public void putAll(Map<? extends K, ? extends V> t) { throw new UnsupportedOperationException("Cannot call putAll() on " + this.getClass().getSimpleName()); } @Override public void clear() { throw new UnsupportedOperationException("Cannot call clear() on " + this.getClass().getSimpleName()); } @Override public Set<K> keySet() { return Collections.unmodifiableSet(this.delegate.keySet()); } @Override public Set<Map.Entry<K, V>> entrySet() { return Collections.unmodifiableMap(this.delegate).entrySet(); } @Override public Collection<V> values() { return Collections.unmodifiableCollection(this.delegate.values()); } @Override public boolean equals(Object o) { return o == this || this.delegate.equals(o); } @Override public int hashCode() { return this.delegate.hashCode(); } @Override public String toString() { return this.delegate.toString(); } }