java转换编码报错java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern

Exception in thread "main" java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: "左右"
at java.net.URLDecoder.decode

%引起

%会转换成%25

解决方案：

    public static String replacer(String str) {
        String data = str;
        try {
            data = data.replaceAll("%(?![0-9a-fA-F]{2})", "%25");
            data = data.replaceAll("\\+", "%2B");
            data = URLDecoder.decode(data, "utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return data;
    }