Java 内蒂似乎忽略了编码

我有一个netty服务器正在运行，它似乎忽略了编码。d3.js中的错误是由PI符号引起的。下面是设置编码的代码。即使在硬编码之后，它仍然不起作用，你知道为什么吗

RandomAccessFile raf;
try {
  raf = new RandomAccessFile(file, "r");
} catch (FileNotFoundException fnfe) {
  sendError(ctx, NOT_FOUND);
  return;
}
long fileLength = raf.length();

HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
setContentTypeHeader(response, file);
setContentLength(response, fileLength);
setDateAndCacheHeaders(response, file);
if (isKeepAlive(request)) {
  response.setHeader(CONNECTION, HttpHeaders.Values.KEEP_ALIVE);
}

// Write the initial line and the header.
ctx.write(response);

// Write the content.
ChunkedFile chunkedFile = new ChunkedFile(raf, 0, fileLength, 8192);
ChannelFuture writeFuture = ctx.write(chunkedFile);

ctx.write(chunkedFile, writeFuture);

以下是

setContentTypeHeader

代码：

private static void setContentTypeHeader(HttpResponse response, File file) {
String contentType = MimeTypes.getContentType(file.getPath());
response.setHeader(CONTENT_TYPE, contentType);
if (!contentType.equals("application/octet-stream")) {
  response.setHeader(CONTENT_ENCODING, "charset=utf-8");
}

}不是字符编码，而是用于压缩，如gzip。响应的字符编码在中指定

private static void setContentTypeHeader(HttpResponse response, File file) {

    String contentType = MimeTypes.getContentType(file.getPath());

    if (!contentType.equals("application/octet-stream")) {
      contentType += "; charset=utf-8";
    }
    response.setHeader(CONTENT_TYPE, contentType);

}