How to read the request body

[funky-eyes]

  onRequestBody(body_buffer_length: usize, end_of_stream: bool): FilterDataStatusValues { 
    const contentType: String = stream_context.headers.request.get("Content-Type");
    if (contentType.toLowerCase()==="application/json") {
      const arrayBuffer: ArrayBuffer = get_buffer_bytes(BufferTypeValues.HttpRequestBody,0, end_of_stream);
      arrayBuffer
    }
    if (contentType.toLowerCase()==="application/x-www-form-urlencoded") {
      const arrayBuffer: ArrayBuffer = get_buffer_bytes(BufferTypeValues.HttpRequestBody,0, end_of_stream);
    }
    return FilterDataStatusValues.Continue;
   }

How do I convert ArrayBuffer to the corresponding data, such as map, json

[funky-eyes]

My requirement is to parse the body, read the corresponding parameters, and put them in the header to pass them upstream