/*
 * 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.
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package org.apache.commons.collections4.set;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Collection;
import java.util.Iterator;
import java.util.NavigableSet;
import java.util.SortedSet;
import java.util.function.Predicate;

import org.apache.commons.collections4.Unmodifiable;
import org.apache.commons.collections4.iterators.UnmodifiableIterator;

Decorates another NavigableSet to ensure it can't be altered.

Attempts to modify it will result in an UnsupportedOperationException.

Type parameters:
  • <E> – the type of the elements in this set
Since:4.1
/** * Decorates another <code>NavigableSet</code> to ensure it can't be altered. * <p> * Attempts to modify it will result in an UnsupportedOperationException. * </p> * * @param <E> the type of the elements in this set * @since 4.1 */
public final class UnmodifiableNavigableSet<E> extends AbstractNavigableSetDecorator<E> implements Unmodifiable {
Serialization version
/** Serialization version */
private static final long serialVersionUID = 20150528L;
Factory method to create an unmodifiable set.
Params:
  • set – the set to decorate, must not be null
Type parameters:
  • <E> – the element type
Throws:
Returns:a new unmodifiable NavigableSet
/** * Factory method to create an unmodifiable set. * * @param <E> the element type * @param set the set to decorate, must not be null * @return a new unmodifiable {@link NavigableSet} * @throws NullPointerException if set is null */
public static <E> NavigableSet<E> unmodifiableNavigableSet(final NavigableSet<E> set) { if (set instanceof Unmodifiable) { return set; } return new UnmodifiableNavigableSet<>(set); } //-----------------------------------------------------------------------
Constructor that wraps (not copies).
Params:
  • set – the set to decorate, must not be null
Throws:
/** * Constructor that wraps (not copies). * * @param set the set to decorate, must not be null * @throws NullPointerException if set is null */
private UnmodifiableNavigableSet(final NavigableSet<E> set) { super(set); } //----------------------------------------------------------------------- @Override public Iterator<E> iterator() { return UnmodifiableIterator.unmodifiableIterator(decorated().iterator()); } @Override public boolean add(final E object) { throw new UnsupportedOperationException(); } @Override public boolean addAll(final Collection<? extends E> coll) { throw new UnsupportedOperationException(); } @Override public void clear() { throw new UnsupportedOperationException(); } @Override public boolean remove(final Object object) { throw new UnsupportedOperationException(); }
Since:4.4
/** * @since 4.4 */
@Override public boolean removeIf(Predicate<? super E> filter) { throw new UnsupportedOperationException(); } @Override public boolean removeAll(final Collection<?> coll) { throw new UnsupportedOperationException(); } @Override public boolean retainAll(final Collection<?> coll) { throw new UnsupportedOperationException(); } // SortedSet //----------------------------------------------------------------------- @Override public SortedSet<E> subSet(final E fromElement, final E toElement) { final SortedSet<E> sub = decorated().subSet(fromElement, toElement); return UnmodifiableSortedSet.unmodifiableSortedSet(sub); } @Override public SortedSet<E> headSet(final E toElement) { final SortedSet<E> head = decorated().headSet(toElement); return UnmodifiableSortedSet.unmodifiableSortedSet(head); } @Override public SortedSet<E> tailSet(final E fromElement) { final SortedSet<E> tail = decorated().tailSet(fromElement); return UnmodifiableSortedSet.unmodifiableSortedSet(tail); } // NavigableSet //----------------------------------------------------------------------- @Override public NavigableSet<E> descendingSet() { return unmodifiableNavigableSet(decorated().descendingSet()); } @Override public Iterator<E> descendingIterator() { return UnmodifiableIterator.unmodifiableIterator(decorated().descendingIterator()); } @Override public NavigableSet<E> subSet(final E fromElement, final boolean fromInclusive, final E toElement, final boolean toInclusive) { final NavigableSet<E> sub = decorated().subSet(fromElement, fromInclusive, toElement, toInclusive); return unmodifiableNavigableSet(sub); } @Override public NavigableSet<E> headSet(final E toElement, final boolean inclusive) { final NavigableSet<E> head = decorated().headSet(toElement, inclusive); return unmodifiableNavigableSet(head); } @Override public NavigableSet<E> tailSet(final E fromElement, final boolean inclusive) { final NavigableSet<E> tail = decorated().tailSet(fromElement, inclusive); return unmodifiableNavigableSet(tail); } //-----------------------------------------------------------------------
Write the collection out using a custom routine.
Params:
  • out – the output stream
Throws:
  • IOException – if an error occurs while writing to the stream
/** * Write the collection out using a custom routine. * * @param out the output stream * @throws IOException if an error occurs while writing to the stream */
private void writeObject(final ObjectOutputStream out) throws IOException { out.defaultWriteObject(); out.writeObject(decorated()); }
Read the collection in using a custom routine.
Params:
  • in – the input stream
Throws:
/** * Read the collection in using a custom routine. * * @param in the input stream * @throws IOException if an error occurs while reading from the stream * @throws ClassNotFoundException if an object read from the stream can not be loaded */
@SuppressWarnings("unchecked") // (1) should only fail if input stream is incorrect private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException { in.defaultReadObject(); setCollection((Collection<E>) in.readObject()); // (1) } }