Why is content seen as text/html?

Question

css, js, jpg, etc in Java Web App are all seen as text/html type.

for example if I put in the url:

domain.com:8080/Application/css/bootstrap.min.css

it loads as text

Content-Type: text/html;charset=UTF-8

The Java web app is fine in local, but when I upload it to the production server the problem occurs.

So in local is fine:

localhost:8080/Application/css/bootstrap.min.css

Content-Type: text/css;charset=UTF-8

Everything was fine for years until a couple of days ago.

Answer 1

ok, I found the problem. Basically in my SecurityFilter.java class, which I set on my web.xml file with the parameter, I was explicitly declaring the ContentType to text/html for all content. I have now deleted the line and everything is seen by the browser in the right MIME type.

public class SecurityFilter implements Filter {
    @Override
    public void doFilter(...) throws ServletException, IOException {
        ...
        response.setContentType("text/html; charset=UTF-8");
        ...
    }
}

The strange thing is that I had this line in my code for years and never caused a problem. I still have no idea what happened in the last few days that caused it to create a problem. If someone has the answer I will sleep better at night knowing the reason.