判断URL是否编码,编码后的sign对签名和验签都有影响,导致验签不通过

package com.example.core.mydemo.java;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;

/**
 * url1=%3D%3D
 * decodedUrl===
 * URL 1 is encoded: true
 * decodedUrl===
 * URL 2 is encoded: false
 * url1=%2B+%2F%3F%25%23%26
 * decodedUrl=+ /?%#&
 * URL 3 is encoded: true
 * decodedUrl= /?#&
 * URL 4 is encoded: false
 * decodedUrl=
 * URL 5 is encoded: true
 * URL 6 is encoded: true
 * java.lang.IllegalArgumentException: URLDecoder: Incomplete trailing escape (%) pattern
 *     at java.net.URLDecoder.decode(URLDecoder.java:187)
 *     at com.example.core.mydemo.java.URLUtils.isUrlEncoded(URLUtils.java:22)
 *     at com.example.core.mydemo.java.URLUtils.main(URLUtils.java:56)
 * */
public class URLUtils {
    public static boolean isUrlEncoded(String url) {
        try {
            String decodedUrl = URLDecoder.decode(url, "UTF-8");
            System.out.println("decodedUrl=" + decodedUrl);
            return !decodedUrl.equals(url);
        } catch (UnsupportedEncodingException e) {
            // 处理异常
            e.printStackTrace();
            return false;
        }catch (IllegalArgumentException ex){
            ex.printStackTrace();
            return true;
        }
    }


    public static void main(String[] args) throws UnsupportedEncodingException {
        String url1  = URLEncoder.encode("==","UTF-8");
        System.out.println("url1=" + url1);
        String url2  = "==";

        System.out.println("URL 1 is encoded: " + isUrlEncoded(url1));
        System.out.println("URL 2 is encoded: " + isUrlEncoded(url2));


        url1  = URLEncoder.encode("+ /?%#&","UTF-8");
        System.out.println("url1=" + url1);
        url2  = " /?#&";  //去掉 + %  否则判断不准或报错 Exception in thread "main" java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: "#&"


        System.out.println("URL 3 is encoded: " + isUrlEncoded(url1));
        System.out.println("URL 4 is encoded: " + isUrlEncoded(url2));

        url1  = "+";
        url2  = "%";
        System.out.println("URL 5 is encoded: " + isUrlEncoded(url1));
        System.out.println("URL 6 is encoded: " + isUrlEncoded(url2));

    }

}