``` //实现big.int 转string ```

import java.math.BigInteger;

public class BigIntToString {
    public static String convertToString(BigInteger bigInt) {
        return bigInt.toString();
    }
}

相关问题

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：int[]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 ... }

下面是一个实现了 countSize 方法和 WordBean 类的示例代码：

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

public class PatternDemo {
    public int countWords(CharSequence content) {
        // 定义单词的正则表达式
        String patternStr = "\\b\\w+\\b";
        Pattern pattern = Pattern.compile(patternStr);
        Matcher matcher = pattern.matcher(content);

        int count = 0;
        while (matcher.find()) {
            count++;
        }

        return count;
    }

    public WordBean[] countSize(CharSequence content) {
        // 定义单词的正则表达式
        String patternStr = "\\b\\w+\\b";
        Pattern pattern = Pattern.compile(patternStr);
        Matcher matcher = pattern.matcher(content);

        // 使用 Map 来统计每个单词的出现次数
        Map<String, Integer> wordCountMap = new HashMap<>();
        while (matcher.find()) {
            String word = matcher.group().toLowerCase();
            if (wordCountMap.containsKey(word)) {
                wordCountMap.put(word, wordCountMap.get(word) + 1);
            } else {
                wordCountMap.put(word, 1);
            }
        }

        // 将统计结果封装到 WordBean 数组中
        WordBean[] result = new WordBean[wordCountMap.size()];
        int i = 0;
        for (Map.Entry<String, Integer> entry : wordCountMap.entrySet()) {
            result[i++] = new WordBean(entry.getKey(), entry.getValue());
        }
        return result;
    }

    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;
    }
}

public class WordBean {
    private String word;
    private int count;

    public WordBean(String word, int count) {
        this.word = word;
        this.count = count;
    }

    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;
    }

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

public class UsePatternDemo {
    public static void main(String[] args) {
        PatternDemo patternDemo = new PatternDemo();
        StringBuilder content = patternDemo.getContent();
        WordBean[] result = patternDemo.countSize(content);
        for (WordBean wordBean : result) {
            System.out.println(wordBean);
        }
    }
}

在这个示例代码中，我们封装了一个 WordBean 类，用来表示单词和它的出现次数。在 countSize 方法中，我们使用正则表达式来匹配文本中的单词，并使用 HashMap 来统计每个单词的出现次数。最后，我们将统计结果封装到 WordBean 数组中返回。在调用者类 UsePatternDemo 中，我们可以测试我们的实现是否正确。

解释这行代码 int count = 0; int index = bigString.indexOf(smallString); while (index >= 0) { count++; index = bigString.indexOf(smallString, index + 1);

这是一段 Java 代码，主要实现的功能是在一个字符串 `bigString` 中查找另一个字符串 `smallString` 出现的次数。具体来说，代码定义了两个整型变量 `count` 和 `index`，初始化时 `count` 被赋值为 0，而 `index` 被赋值为 `bigString` 中第一次出现 `smallString` 的位置。然后通过一个 while 循环，不断地查找 `smallString` 在 `bigString` 中的下一个出现位置，每找到一次就将 `count` 增加 1，直到查找完所有的位置后退出循环。具体实现是通过调用 `bigString.indexOf(smallString, index + 1)` 方法来查找下一个出现位置，如果找到了就返回该位置的下标，否则返回 -1。因此，当 `index` 小于 0（即 `smallString` 未在 `bigString` 中出现过）或查找完所有位置时，循环将结束。最终，`count` 的值就是 `smallString` 在 `bigString` 中出现的次数。