Java正则表达式使用例子

以下是一个Java正则表达式的使用例子：

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

public class RegexExample {
    public static void main(String[] args) {
        // 匹配
        String input = "java123456Regular6543210Expression";
        String regex = "\\d"; // 匹配数字
        Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher(input);
        while (matcher.find()) {
            System.out.println("匹配到的字符：" + matcher.group());
        }

        // 替换
        String replaceRegex = "\\d{5,}"; // 匹配至少5个连续数字
        String replacedString = input.replaceAll(replaceRegex, "#");
        System.out.println("替换后的字符串：" + replacedString);

        // 获取
        String extractRegex = "\\d{5,}"; // 匹配至少5个连续数字
        Pattern extractPattern = Pattern.compile(extractRegex);
        Matcher extractMatcher = extractPattern.matcher(input);
        if (extractMatcher.find()) {
            System.out.println("提取到的字符串：" + extractMatcher.group());
        }
    }
}