HttpServeltResponse send error message in UTF-8

I used to fix a bug of httpServletResponse sending error message in utf-8. It was the response of an ajax call. If there was error, it need send error with error message back to the client to trigger the method below in client javascript.

error: function( jqXHR xhr, String textStatus, String errorThrown ) 

The previous guy used this code in java

response.sendError(11, errorMessage);

and tried to get the error message with this code in javascript.

xhr.statusText

This did not work if there was French character with accent in message.

The solution is like this, in java code

response.setStatus(11);
response.setContentType("text/html;charset=UTF-8");
response.getWriter().write(errorMessage);

in javascript, get responseText instead of statusText

xhr.responseText

Before I found this, I also tried this. Although it worked on UI, but I saw error messages in log file from weblogic.

response.setContentType("text/html;charset=UTF-8");
response.sendError(11, errorMessage);

The error message is about the

ProtocolException: Didn't meet stated Content-Length

Here is a similar issue