java设计一个类，统计一个字符串中单词的总个数，设单词之间用一个或多个空格分隔，该字符串只由字母和空格组成，并分别计算每个单词在字符串中出现的次数？

可以使用Java的正则表达式来解决这个问题。以下是一个示例代码：

import java.util.HashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class WordCounter {
    private String text;
    private int wordCount;
    private HashMap<String, Integer> wordMap;

    public WordCounter(String text) {
        this.text = text;
        this.wordCount = 0;
        this.wordMap = new HashMap<>();
        countWords();
    }

    private void countWords() {
        Pattern pattern = Pattern.compile("\\b\\w+\\b");
        Matcher matcher = pattern.matcher(text);
        while (matcher.find()) {
            wordCount++;
            String word = matcher.group().toLowerCase();
            if (wordMap.containsKey(word)) {
                wordMap.put(word, wordMap.get(word) + 1);
            } else {
                wordMap.put(word, 1);
            }
        }
    }

    public int getWordCount() {
        return wordCount;
    }

    public HashMap<String, Integer> getWordMap() {
        return wordMap;
    }
}

使用方法如下：

String text = "This is a sample text. The text contains some words that may repeat.";
WordCounter counter = new WordCounter(text);
System.out.println("Total word count: " + counter.getWordCount());
System.out.println("Word frequency:");
HashMap<String, Integer> wordMap = counter.getWordMap();
for (String word : wordMap.keySet()) {
    System.out.println(word + ": " + wordMap.get(word));
}

输出结果如下：

Total word count: 13
Word frequency:
text: 2
repeat: 1
a: 1
is: 1
some: 1
contains: 1
words: 1
may: 1
this: 1
sample: 1
that: 1
the: 1