在Java中解码和替换字符串中的十六进制值

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

public class HexStringDecoder {
    
    // 解码十六进制字符串
    public String decodeHexString(String input) {
        StringBuilder decodedString = new StringBuilder();
        Pattern pattern = Pattern.compile("\\\\x([0-9A-Fa-f]{2})");
        Matcher matcher = pattern.matcher(input);
        
        while (matcher.find()) {
            int hexValue = Integer.parseInt(matcher.group(1), 16);
            decodedString.append((char) hexValue);
        }
        
        return decodedString.toString();
    }
    
    // 替换十六进制字符串
    public String replaceHexString(String input, String replacement) {
        Pattern pattern = Pattern.compile("\\\\x([0-9A-Fa-f]{2})");
        Matcher matcher = pattern.matcher(input);
        String replacedString = matcher.replaceAll(replacement);
        
        return replacedString;
    }
}

public class Main {
    public static void main(String[] args) {
        HexStringDecoder decoder = new HexStringDecoder();
        
        String input = "Hello\\x20World!\\x21";
        String decodedString = decoder.decodeHexString(input);
        System.out.println("Decoded String: " + decodedString);
        
        String replacement = "[REPLACED]";
        String replacedString = decoder.replaceHexString(input, replacement);
        System.out.println("Replaced String: " + replacedString);
    }
}