请设计一个类型，提供如下方法 提示 要统计每个单词出现的次数，由于一个方法不能返回2种类型，我们需要把单词和它的出现次数封装到一个类中 去，所以，可以定义一个类型如下： 由于我们统计的有多个单词，所以，我们上面的 countSize 方法的返回类型就可以设计成 WordBean[],如下： public class PatternDemo { //此方法用来统计 content 中的英文单词个数， 请使用正则表达式来做，单词的正则表达式请自行编写， public int countWords(CharSequence content) { ... } //此方法返回一串固定的字符串，已写好，可以直接用。 public StringBuilder getContent() { //此方法的内容如下： StringBuilder builder = new StringBuilder(); builder.append("Hooray! It's snowing! It's time to make a snowman.James runs out. He makes a big pile of snow. He puts a big snowball on top. He adds a scarf and a hat. He adds an orange for the nose. He adds coal for the eyes and buttons.In the evening, James opens the door. What does he see? The snowman is moving! James invites him in. The snowman has never been inside a house. He says hello to the cat. He plays with paper towels.A moment later, the snowman takes James's hand and goes out.They go up, up, up into the air! They are flying! What a wonderful night!The next morning, James jumps out of bed. He runs to the door.He wants to thank the snowman. But he's gone."); // return builder; } //此方法统计出每个单词[不考虑大小写]出现的次数，数据结构请自行定义,设计如下： public ? countSize(CharSequence content) { //TODO ... } //注：? 处是你需要去思考，该设计什么结构来存放结果 } public class WordBean { //属性 private String word; //单词 private int count; //出次 //TODO 请自行完成构造、getter/setter、toString、等相关方法 } public WordBean[] countSize(CharSequence content) { //TODO ... } 最后写一个调用者类，来测试你的实现，如下： public class UsePatternDemo() { public static void main(String[] args) { //TODO ... }

可以使用 HashMap 来存储每个单词出现的次数，设计如下：

public class PatternDemo {
    //此方法用来统计 content 中的英文单词个数， 请使用正则表达式来做，单词的正则表达式请自行编写，
    public int countWords(CharSequence content) {
        //定义单词正则表达式
        String wordRegex = "\\b[a-zA-Z]+\\b";
        //统计单词个数
        Pattern pattern = Pattern.compile(wordRegex);
        Matcher matcher = pattern.matcher(content);
        int count = 0;
        while (matcher.find()) {
            count++;
        }
        return count;
    }

    //此方法返回一串固定的字符串，已写好，可以直接用。
    public StringBuilder getContent() {
        StringBuilder builder = new StringBuilder();
        builder.append("Hooray! It's snowing! It's time to make a snowman.James runs out. He makes a big pile of snow. He puts a big snowball on top. He adds a scarf and a hat. He adds an orange for the nose. He adds coal for the eyes and buttons.In the evening, James opens the door. What does he see? The snowman is moving! James invites him in. The snowman has never been inside a house. He says hello to the cat. He plays with paper towels.A moment later, the snowman takes James's hand and goes out.They go up, up, up into the air! They are flying! What a wonderful night!The next morning, James jumps out of bed. He runs to the door.He wants to thank the snowman. But he's gone.");
        return builder;
    }

    //此方法统计出每个单词[不考虑大小写]出现的次数，数据结构请自行定义,设计如下：
    public HashMap<String, Integer> countSize(CharSequence content) {
        //定义单词正则表达式
        String wordRegex = "\\b[a-zA-Z]+\\b";
        //统计每个单词出现的次数
        Pattern pattern = Pattern.compile(wordRegex);
        Matcher matcher = pattern.matcher(content);
        HashMap<String, Integer> map = new HashMap<>();
        while (matcher.find()) {
            String word = matcher.group().toLowerCase(); //转换为小写
            if (map.containsKey(word)) {
                map.put(word, map.get(word) + 1);
            } else {
                map.put(word, 1);
            }
        }
        return map;
    }

}

public class WordBean {
    //属性
    private String word; //单词
    private int count; //出现次数

    //构造方法
    public WordBean(String word, int count) {
        this.word = word;
        this.count = count;
    }

    //getter/setter方法
    public String getWord() {
        return word;
    }

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

    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }

    //toString方法
    @Override
    public String toString() {
        return "WordBean{" +
                "word='" + word + '\'' +
                ", count=" + count +
                '}';
    }
}

public WordBean[] countSize(CharSequence content) {
    HashMap<String, Integer> map = countSize(content);
    WordBean[] result = new WordBean[map.size()];
    int i = 0;
    for (String key : map.keySet()) {
        result[i++] = new WordBean(key, map.get(key));
    }
    return result;
}

public class UsePatternDemo {
    public static void main(String[] args) {
        PatternDemo demo = new PatternDemo();
        StringBuilder content = demo.getContent();
        int countWords = demo.countWords(content);
        System.out.println("单词个数：" + countWords);
        HashMap<String, Integer> map = demo.countSize(content);
        for (String key : map.keySet()) {
            System.out.println(key + "出现次数：" + map.get(key));
        }
        WordBean[] wordBeans = demo.countSize(content);
        for (WordBean wordBean : wordBeans) {
            System.out.println(wordBean);
        }
    }
}