如何限制打印出的字符串数量(JAVA)

String str = "这是一个示例字符串";
String limitedStr = str.substring(0, 10);
System.out.println(limitedStr);

String str = "这是一个示例字符串";
StringBuilder limitedStr = new StringBuilder();
for (int i = 0; i < 10 && i < str.length(); i++) {
    limitedStr.append(str.charAt(i));
}
System.out.println(limitedStr.toString());

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

public class Main {
    public static void main(String[] args) {
        String str = "这是一个示例字符串";
        Pattern pattern = Pattern.compile("^(.{0,10})");
        Matcher matcher = pattern.matcher(str);
        if (matcher.find()) {
            String limitedStr = matcher.group(1);
            System.out.println(limitedStr);
        }
    }
}