java怎么正则替换，怎么对正则匹配值做自定义处理（自定义正则替换工具类）

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

public class RegexReplaceUtils {

    private RegexReplaceUtils() {
    }

    public static String regexReplace(String str, String regex, ReplaceHandler handler) {
        return regexReplace(str, Pattern.compile(regex), handler);
    }

    public static String regexReplace(String str, Pattern pattern, ReplaceHandler handler) {
        if (str == null || str.isEmpty()) {
            return str;
        }
        Matcher matcher = pattern.matcher(str);

        boolean result = matcher.find();
        if (!result) {
            // normal char sequence
            return str;
        }

        int start = 0;
        StringBuilder sb = new StringBuilder();
        do {
            // append before
            sb.append(str, start, matcher.start());
            // append replacement
            sb.append(handler.onReplace(str.substring(matcher.start(), matcher.end())));
            start = matcher.end();
            result = matcher.find();
        } while (result);

        // append tail
        if (start < str.length()) {
            sb.append(str, start, str.length());
        }

        return sb.toString();
    }

    public interface ReplaceHandler {
        Object onReplace(String token);
    }
}

// 普通调用
RegexReplaceUtils.regexReplace("DXBTECH-\\9AD8", "\\\\[A-F0-9]{4}", new RegexReplaceUtils.ReplaceHandler() {
            @Override
            public Object onReplace(String token) {
                return (char) Integer.parseInt(StringUtils.substring(token, 1), 16);
            }
        });

// lambda调用
RegexReplaceUtils.regexReplace("DXBTECH-\\9AD8", "\\\\[A-F0-9]{4}", token -> (char) Integer.parseInt(StringUtils.substring(token, 1), 16))