11章-练习22

import java.util.*;

/**
 * 练习22：修改前一个练习，使其用一个包含有一个String域和一个计数域的类来存储每个不同的单词，并使用一个由这些对象构成的Set来维护单词列表。
 */
public class Exercise22 {

    public static void main(String[] args) {

        Set<WordWithNum> set = new HashSet<WordWithNum>();
        List<String> wordList = new TextFile("SetOperations.java", "\\W+");

        for (String word : wordList) {
            Iterator<WordWithNum> it = set.iterator();
            WordWithNum wordNum = new WordWithNum();
            wordNum.setWord(word);
            if (set.contains(wordNum)) {
                while (it.hasNext()) {
                    WordWithNum w = it.next();
                    if (w.getWord().equals(word)) {
                        w.addNum();
                    }
                }
            } else {
                wordNum.setNum(1);
            }
            set.add(wordNum);
        }
        System.out.println(set);
    }
}

/**
 * 需要重写equals方法，判断是否是同一个word
 */
class WordWithNum {

    private String word;
    private Integer num;

    public void addNum() {
        num++;
    }

    public String getWord() {
        return word;
    }

    public void setWord(String word) {
        this.word = word;
    }

    public Integer getNum() {
        return num;
    }

    public void setNum(Integer num) {
        this.num = num;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        WordWithNum wordNum = (WordWithNum) o;
        return Objects.equals(word, wordNum.word);
    }

    @Override
    public int hashCode() {
        return Objects.hash(word);
    }

    @Override
    public String toString() {
        return "WordNum{" +
                "word='" + word + '\'' +
                ", num=" + num +
                '}';
    }
}
/* Output:
[WordNum{word='package', num=1}, WordNum{word='void', num=1}, WordNum{word='false', num=2}, WordNum{word='print', num=8}, WordNum{word='contains', num=2}, WordNum{word='util', num=3}, WordNum{word='set2', num=11}, WordNum{word='added', num=2}, WordNum{word='to', num=2}, WordNum{word='set1', num=23}, WordNum{word='true', num=2}, WordNum{word='com', num=2}, WordNum{word='import', num=4}, WordNum{word='SetOperations', num=2}, WordNum{word='example', num=2}, WordNum{word='demo', num=2}, WordNum{word='Print', num=1}, WordNum{word='split', num=3}, WordNum{word='class', num=1}, WordNum{word='public', num=2}, WordNum{word='Output', num=1}, WordNum{word='HashSet', num=3}, WordNum{word='new', num=2}, WordNum{word='static', num=2}, WordNum{word='add', num=1}, WordNum{word='in', num=4}, WordNum{word='containsAll', num=2}, WordNum{word='elevensection', num=2}, WordNum{word='args', num=1}, WordNum{word='Set', num=3}, WordNum{word='A', num=4}, WordNum{word='B', num=4}, WordNum{word='C', num=4}, WordNum{word='D', num=4}, WordNum{word='E', num=4}, WordNum{word='F', num=4}, WordNum{word='G', num=4}, WordNum{word='H', num=6}, WordNum{word='I', num=3}, WordNum{word='J', num=3}, WordNum{word='remove', num=1}, WordNum{word='String', num=5}, WordNum{word='addAll', num=3}, WordNum{word='K', num=3}, WordNum{word='main', num=1}, WordNum{word='L', num=3}, WordNum{word='removed', num=2}, WordNum{word='M', num=4}, WordNum{word='N', num=3}, WordNum{word='holding', num=1}, WordNum{word='java', num=4}, WordNum{word='removeAll', num=1}, WordNum{word='X', num=4}, WordNum{word='Y', num=4}, WordNum{word='from', num=2}, WordNum{word='Z', num=4}, WordNum{word='Collections', num=4}]
 *///:~