@Override
    public String getContentType() {
        String filename = file.getPath().getName();
        int lastDotIndex = filename.lastIndexOf('.');
        if (lastDotIndex >= 0) {
            String contentType = contentTypeByExtension.get(filename.substring(lastDotIndex + 1));
            if (contentType != null) return contentType;
        }
        return DEFAULT_MIME_TYPE;
    }
Represents a response for a request to read contents of a file.

@author Ulf Lilleengen
configserver/src/main/java/com/yahoo/vespa/config/server/http/SessionContentReadResponse.java