URL Encode and Decode Special character in Java

In Java, I need to use HTTP Post to send request to server, but if in the parameter of the URL contains some special character it throws below Exception

java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - For input string: "&'"

The code to send data

DefaultHttpClient httpclient = new DefaultHttpClient(); 
   HttpPost httpPost = new HttpPost(URL); 

   String sessionId = RequestUtil.getRequest().getSession().getId();
   String data = arg.getData().toString();

   List<NameValuePair> params = new ArrayList<NameValuePair>();   
   params.add(new BasicNameValuePair(param1, data));
   params.add(new BasicNameValuePair(param2, sessionId));
         httpPost.setEntity(new UrlEncodedFormEntity(params, "UTF-8"));           

   HttpResponse response = (HttpResponse) httpclient.execute(httpPost);

And at the server side, i use the below code to read information

 String data = request.getParameter(param1);
   if (data != null) {
    actionArg = new ChannelArg(URLDecoder.decode(data, "UTF-8"));
   }

The code works correctly but if i input some special character like [aああ#$%&'(<>?/.,あああああ], it will throw exception. I wonder if someone could help me some hint to be able to encode and decode special characters?

Thank you very much in advance.

Sadly url encoder will not solve your problem. I had this problem and used a custom utility. I remember this I got from googling ;).

http://www.javapractices.com/topic/TopicAction.do?Id=96

To encode text for safe passage through the internets:

import java.net.*;
...
try {
    encodedValue= URLEncoder.encode(rawValue, "UTF-8");
} catch (UnsupportedEncodingException uee) { }

And to decode:

try {
    decodedValue = URLDecoder.decode(rawValue, "UTF-8");
} catch (UnsupportedEncodingException uee) { }

String data = request.getParameter(param1);

If this is the servlet API, the parameters have already been decoded. No further handling of percent-encoding is necessary.

I haven't used HttpClient, but ensure it is sending the encoding in the header:

Content-type: application/x-www-form-urlencoded; charset=UTF-8

Or, if you must, set the known encoding before any getParameter calls:

request.setCharacterEncoding("UTF-8");

try guava

use com.google.common.net.UrlEscapers

it works fine with chinese

like this:

Escaper escaper = UrlEscapers.urlFragmentEscaper();
String result = escaper.escape(yoururl);

来源：https://stackoverflow.com/questions/4841331/url-encode-and-decode-special-character-in-java

标签

java

urlencode