    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      https://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.lang3.util;
    019
    020import java.util.ArrayList;
    021import java.util.Iterator;
    022import java.util.List;
    023import java.util.Objects;
    024import java.util.StringTokenizer;
    025import java.util.stream.Stream;
    026import java.util.stream.StreamSupport;
    027
    028import org.apache.commons.lang3.ArrayUtils;
    029
    030/**
    031 * A {@link StringTokenizer} that implements {@link Iterable}{@code <String>} and conversion methods {@link #toList()} and {@link #toStream()}.
    032 *
    033 * @since 3.18.0
    034 */
    035public class IterableStringTokenizer extends StringTokenizer implements Iterable<String> {
    036
    037    /**
    038     * Constructs a new instance like {@link StringTokenizer#StringTokenizer(String, String, boolean)}.
    039     *
    040     * @param str a string to be parsed.
    041     * @exception NullPointerException if str is {@code null}.
    042     */
    043    public IterableStringTokenizer(final String str) {
    044        super(str);
    045    }
    046
    047    /**
    048     * Constructs a new instance like {@link StringTokenizer#StringTokenizer(String, String, boolean)}.
    049     *
    050     * @param str   a string to be parsed.
    051     * @param delim the delimiters.
    052     * @exception NullPointerException if str is {@code null}.
    053     */
    054    public IterableStringTokenizer(final String str, final String delim) {
    055        super(str, delim);
    056    }
    057
    058    /**
    059     * Constructs a new instance like {@link StringTokenizer#StringTokenizer(String, String, boolean)}.
    060     *
    061     * @param str          a string to be parsed.
    062     * @param delim        the delimiters.
    063     * @param returnDelims flag indicating whether to return the delimiters as tokens.
    064     * @exception NullPointerException if str is {@code null}.
    065     */
    066    public IterableStringTokenizer(final String str, final String delim, final boolean returnDelims) {
    067        super(str, delim, returnDelims);
    068    }
    069
    070    @Override
    071    public Iterator<String> iterator() {
    072        return new Iterator<String>() {
    073
    074            @Override
    075            public boolean hasNext() {
    076                return hasMoreElements();
    077            }
    078
    079            @Override
    080            public String next() {
    081                return Objects.toString(nextElement(), null);
    082            }
    083        };
    084    }
    085
    086    /**
    087     * Returns a new {@code String[]} containing the tokenizer elements.
    088     *
    089     * @return a new {@code String[]}.
    090     */
    091    public String[] toArray() {
    092        return toList().toArray(ArrayUtils.EMPTY_STRING_ARRAY);
    093    }
    094
    095    /**
    096     * Returns a new {@link List} containing the tokenizer elements.
    097     *
    098     * @return a new {@link List}.
    099     */
    100    public List<String> toList() {
    101        final List<String> list = new ArrayList<>();
    102        forEach(list::add);
    103        return list;
    104    }
    105
    106    /**
    107     * Returns a sequential stream on this Iterable instance.
    108     *
    109     * @return a sequential stream on this Iterable instance.
    110     */
    111    public Stream<String> toStream() {
    112        return StreamSupport.stream(spliterator(), false);
    113    }
    114}