如何避免Java正则表达式匹配中的隐式"^"和"$"？

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

public class RegularExpressionExample {
    public static void main(String[] args) {
        String regex = "\\d{3}"; // 匹配三个数字
        String input = "123456789";

        Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher(input);

        while (matcher.find()) {
            System.out.println("匹配到的数字: " + matcher.group());
        }
    }
}