描述
报错如下
java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: “����”
如果url中有%或者+会报上面的错误
这里以%为例：
浏览器URL只能是英文、阿拉伯数字和标点符号，中文的话需要编码解码，浏览器遇到中文会自动的编码为%B2这样的%加16进制的，可是%不会处理。
就像”你好啊%“，最终变成了”%B2%E2%CA%D4%B1%A8%B4%ED%“
%在被编码的时候变成了%25，我们传进来的url本来包括%的话，浏览器不会进行处理，还是%，但是在解码的时候，程序认为%后面还应该有25，可是的的确确没有这个25，解码的程序不认识了，不知道怎么解码了，就抛出了异常java.lang.IllegalArgumentException
2019-11-4同类问题更新
Exception in thread “main” java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: “u8”
后面是u8说明是中文的
解决
针对于For input string: "����"这种普通的
原来的解码前加两行代码
val = val.replaceAll("%(?![0-9a-fA-F]{2})", "%25");
val = val.replaceAll("\\+", "%2B");
val = URLDecoder.decode(val, "utf-8");
针对于For input string: "u8"这种中文的
需要unescape 解码
原因分析：
java的StringEscapeUtils转义与反转义
这里分析可能是客户传递的json字符串经过了Escape转换为了Unicode编码（可能是前端进行的转化），所以需要转回去（一般浏览器中有中文会自动转换的，这种转换成的通过decode不会报错，但是unicode编码这种是会报错的）
解决方式：
添加工具类
package demo;
import org.apache.commons.lang3.StringEscapeUtils;
public class Escape
{
private final static String[] hex = {
"00","01","02","03","04","05","06","07","08","09","0A","0B","0C","0D","0E","0F",
"10","11","12","13","14","15","16","17","18","19","1A","1B","1C","1D","1E","1F",
"20","21","22","23","24","25","26","27","28","29","2A","2B","2C","2D","2E","2F",
"30","31","32","33","34","35","36","37","38","39","3A","3B","3C","3D","3E","3F",
"40","41","42","43","44","45","46","47","48","49","4A","4B","4C","4D","4E","4F",
"50","51","52","53","54","55","56","57","58","59","5A","5B","5C","5D","5E","5F",
"60","61","62","63","64","65","66","67","68","69","6A","6B","6C","6D","6E","6F",
"70","71","72","73","74","75","76","77","78","79","7A","7B","7C","7D","7E","7F",
"80","81","82","83","84","85","86","87","88","89","8A","8B","8C","8D","8E","8F",
"90","91","92","93","94","95","96","97","98","99","9A","9B","9C","9D","9E","9F",
"A0","A1","A2","A3","A4","A5","A6","A7","A8","A9","AA","AB","AC","AD","AE","AF",
"B0","B1","B2","B3","B4","B5","B6","B7","B8","B9","BA","BB","BC","BD","BE","BF",
"C0","C1","C2","C3","C4","C5","C6","C7","C8","C9","CA","CB","CC","CD","CE","CF",
"D0","D1","D2","D3","D4","D5","D6","D7","D8","D9","DA","DB","DC","DD","DE","DF",
"E0","E1","E2","E3","E4","E5","E6","E7","E8","E9","EA","EB","EC","ED","EE","EF",
"F0","F1","F2","F3","F4","F5","F6","F7","F8","F9","FA","FB","FC","FD","FE","FF"
};
private final static byte[] val = {
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F
};
public static String escape(String s) {
StringBuffer sbuf = new StringBuffer();
int len = s.length();
for (int i = 0; i < len; i++) {
int ch = s.charAt(i);
if (ch == ' ') { // space : map to '+'
sbuf.append('+');
} else if ('A' <= ch && ch <= 'Z') { // 'A'..'Z' : as it was
sbuf.append((char)ch);
} else if ('a' <= ch && ch <= 'z') { // 'a'..'z' : as it was
sbuf.append((char)ch);
} else if ('0' <= ch && ch <= '9') { // '0'..'9' : as it was
sbuf.append((char)ch);
} else if (ch == '-' || ch == '_' // unreserved : as it was
|| ch == '.' || ch == '!'
|| ch == '~' || ch == '*'
|| ch == '/' || ch == '('
|| ch == ')') {
sbuf.append((char)ch);
} else if (ch <= 0x007F) { // other ASCII : map to %XX
sbuf.append('%');
sbuf.append(hex[ch]);
} else { // unicode : map to %uXXXX
sbuf.append('%');
sbuf.append('u');
sbuf.append(hex[(ch >>> 8)]);
sbuf.append(hex[(0x00FF & ch)]);
}
}
return sbuf.toString();
}
public static String unescape(String s) {
StringBuffer sbuf = new StringBuffer();
int i = 0;
int len = s.length();
while (i < len) {
int ch = s.charAt(i);
if (ch == '+') { // + : map to ' '
sbuf.append(' ');
} else if ('A' <= ch && ch <= 'Z') { // 'A'..'Z' : as it was
sbuf.append((char)ch);
} else if ('a' <= ch && ch <= 'z') { // 'a'..'z' : as it was
sbuf.append((char)ch);
} else if ('0' <= ch && ch <= '9') { // '0'..'9' : as it was
sbuf.append((char)ch);
} else if (ch == '-' || ch == '_' // unreserved : as it was
|| ch == '.' || ch == '!'
|| ch == '~' || ch == '*'
|| ch == '/' || ch == '('
|| ch == ')') {
sbuf.append((char)ch);
} else if (ch == '%') {
int cint = 0;
if ('u' != s.charAt(i+1)) { // %XX : map to ascii(XX)
cint = (cint << 4) | val[s.charAt(i+1)];
cint = (cint << 4) | val[s.charAt(i+2)];
i+=2;
} else { // %uXXXX : map to unicode(XXXX)
cint = (cint << 4) | val[s.charAt(i+2)];
cint = (cint << 4) | val[s.charAt(i+3)];
cint = (cint << 4) | val[s.charAt(i+4)];
cint = (cint << 4) | val[s.charAt(i+5)];
i+=5;
}
sbuf.append((char)cint);
}
i++;
}
return sbuf.toString();
}
public static void main(String[] args) {
String stest = "苏州";
System.out.println(stest);
System.out.println(escape(stest));
System.out.println(unescape("%u82CF%u5DDE"));
}
}
这里的util类转自URLDecoder失败 感谢
总体解决方案
try {
//这里要替换的是单独的%而不是全部的%
val = val.replaceAll("%(?![0-9a-fA-F]{2})", "%25");
val = val.replaceAll("\\+", "%2B");
//解决中文的问题
val = EscapeUtil.unescape(val);
val = URLDecoder.decode(val,"UTF-8");
} catch (IllegalArgumentException ex) {
//未知的问题
log.warn("ParamProcessor exception --->", ex);
}
Demo
package com.leesin;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
public class DecodeTest {
public static void main(String[] args) throws UnsupportedEncodingException {
String testString = "测试没有特殊字符的解码";
String encode = URLEncoder.encode(testString, "gbk");
String decode = URLDecoder.decode(encode, "gbk");
System.out.println("没有特殊字符解码的--" + encode);
System.out.println("没有特殊字符解码的--" + decode);
String testString1 = "%测试有特殊字符的解码";
String encode1 = URLEncoder.encode(testString1, "gbk");
String decode1 = URLDecoder.decode(encode1, "gbk");
System.out.println("有特殊字符解码的--" + encode1);
System.out.println("有特殊字符解码的--" + decode1);
String testString2 = "测试报错%";
// String encode2 = URLEncoder.encode(testString2, "gbk");
String encode2 = "%B2%E2%CA%D4%B1%A8%B4%ED%";
String decode2 = URLDecoder.decode(encode2, "gbk");
System.out.println("有特殊字符解码的--" + encode2);
System.out.println("有特殊字符解码的--" + decode2);
}
}
结果
感谢
java转义问题【java.lang.IllegalArgumentException: URLDecoder: Incomplete trailing escape (%) pattern】