Tutorial :HttpServletRequest - setCharacterEncoding seems to do nothing



Question:

I am trying to read UTF-8 info from the request. I used "request.setCharacterEncoding("UTF-8");", but it seems to do nothing - the info read is non UTF-8.

What am i doing wrong?


Solution:1

If you are using tomcat, you should also set the URIEncoding to UTF-8 in your connectors:

<Server port="8105" shutdown="SHUTDOWN">  ...      <Service name="Catalina">          <Connector port="8180" URIEncoding="UTF-8" />          <Engine name="Catalina" defaultHost="localhost">              <Host name="localhost" appBase="webapps" />          </Engine>      </Service>  </Server>  


Solution:2

The HttpServletRequest#setCharacterEncoding() has only effect when the request is a POST request and the request body is not processed yet.

So if it doesn't work in your case, then it can have two causes:

  1. You're actually firing a GET request. I.e. the request parameters are sent from client to server in the request URL instead of the request body. The request URL is processed by the webserver, not by the Servlet API. So, to fix this, you need to configure the webserver in question to decode the request URL (URI) using the specified character encoding. In case of for example Apache Tomcat, you need to set the URIEncoding attribute of the <Connector> element in server.xml to UTF-8.

  2. You're correctly using POST, but you've already (indirectly) processed the request body so that it's too late to change the character encoding. The request body will be fully processed only whenever the first call on a getParameterXXX() method is made. There are several of them. It won't be re-processed on subsequent calls. When nailing down who's calling this method, don't forget to take all declared Filter instances in web.xml into account. Some of them might grab and scan the parameters.

If that still doesn't help anything, then the only possible cause left is that the display console or logger or whatever you're using to print/determine/debug the obtained request parameter does not support UTF-8. You'd like to reconfigure the console/logger/etc to use UTF-8 instead to display the characters. If it's for example the Eclipse console, then you can set it by Window > Preferences > General > Workspace > Text File Encoding.

See also:


Solution:3

this method is really stupid. it shouldn't be there, and you shouldn't use it.

for a body in a POST request, the encoding should have been explicitly defined by the client in the Content-Type header. if not, it's a bad request. [1]

for a GET request URI, the client cannot specify encoding, and the server must have an implicit encoding, and the programmer needs to set the encoding, yet that method does not exist in Servlet API!

however, you servlet container could have a proprietary way of doing that.

the best way is probably set the default encoding of your JVM to UTF-8.

1: http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1

The "charset" parameter is used with some media types to define the character set (section 3.4) of the data. When no explicit charset parameter is provided by the sender, media subtypes of the "text" type are defined to have a default charset value of "ISO-8859-1" when received via HTTP. Data in character sets other than "ISO-8859-1" or its subsets MUST be labeled with an appropriate charset value.


Solution:4

The problem is dependent on which application server is used. The best description, which I found in this link.

In some application servers the request.setCharacterEncoding(...) has no effect until you set the application encoding using a descriptor. The most complicated are JBoss, Apache Tomcat, Glassfish. Better is WebLogic, the best is Jetty (UTF-8 is default setting).

In my case I must create a glassfish-web.xml descriptor and put there the parameter-encoding tag. In my case, for GlassFish:

<glassfish-web-app error-url="">      <!-- request.setCharacterEncoding("UTF-8") not functioning without this setting-->      <parameter-encoding default-charset="UTF-8" />  </glassfish-web-app>  


Solution:5

Just to comfirm that for POST parameters you have to call request.setCharacterEncoding(...) before get parameters. And for GET parameters, it is depended on what web container you are using (use Maurice Perry's answer for Tomcat).

Please check this link for more info. "Character Conversions from Browser to Database" http://java.sun.com/developer/technicalArticles/Intl/HTTPCharset/


Solution:6

are you doing it after any request.getParameter call.

request.setCharacterEncoding("UTF-8") must be called prior to any request.getParameter() call.


Solution:7

(as for the very first question..)
if you read parameters from the body it is also possible to read each item with its own encoding (look in the last line):

ServletFileUpload upload = new ServletFileUpload(new DiskFileItemFactory());  List items = null;  try {      items = upload.parseRequest(request);  } catch (FileUploadException ex) {      logger.warn("Fail during file upload");      return uploads;  }    Iterator itr = items.iterator();  while (itr.hasNext()) {      FileItem item = (FileItem) itr.next();      if (item.isFormField()) {          String name = item.getFieldName();          System.out.println("name: " + name);          String value = item.getString();          System.out.println("get as utf8 - "+item.getString("UTF-8"));  


Solution:8

for jboss/wildfly there is a feature request https://issues.jboss.org/browse/WFLY-2533

Drop this into WEB-INF/jboss-web.xml:

<?xml version="1.0" encoding="UTF-8"?>  <jboss-web version="8.0" xmlns="http://www.jboss.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"      xsi:schemaLocation="http://www.jboss.org/j2ee/schema/jboss-web_8_0.xsd">      <!-- browser tend to not send encoding information, so we have to match the servlet container's      default encoding with our requested form data encoding: -->      <default-encoding>UTF-8</default-encoding>  </jboss-web>  

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