问如何在dart中解析http多部分/混合响应(颤振)

EN

import 'dart:async';
import 'dart:convert';
import 'dart:io';
import "package:http/http.dart" as http;
import 'package:mime/mime.dart';

 Future<void> openRevs() async {
    String auth = _generateauth(couchUsername, couchPassword);
    String url = couchServer +
        "/" +
        Uri.encodeComponent(couchDBName) +
        "/" +
        Uri.encodeComponent("patient/1001") +
        "?open_revs=" +
        Uri.encodeComponent("""["1-6bb2dd39beefd1dd2ae1f47c01caea37",
"2-logi",
"2-712b79fb62e64bbf3eab6c009334fb60",
"3-flower",
"4-bloom",
"3-b0c4b3b87373a410c4ad3710a39d7f81"
]""") +
        "&latest=true";
    http.Client client = http.Client();
    http.Request rq = http.Request("GET", Uri.parse(url));
    rq.headers.addAll({"Authorization": auth});
    http.StreamedResponse sr = await client.send(rq);
    if (sr.statusCode != 200) throw Exception("Server Error!");
    if (sr.headers["server"] == null ||
        !sr.headers["server"]!.contains("CouchDB"))
      throw Exception("Invalid Server: Not a CouchDB Server!");

    print(sr.headers);

    // Generate REGEX to get boundary from content-type header
    RegExp boundaryget = RegExp('boundary="(.+)"');
    String contentType = sr.headers["content-type"].toString();

    // Get the boundary
    final match = boundaryget.firstMatch(contentType);
    String boundary = match?.group(1) as String;

    // Get the completed response from the server
    List<int> completeResponse = await sr.stream.toBytes();

    // Create a list for stream creation..
    List<List<int>> cr = [completeResponse];

    // generate MimeMultipart Stream
    Stream<MimeMultipart> mm =
        MimeMultipartTransformer(boundary).bind(Stream.fromIterable(cr));

    // We put the parsed responses here...
    List<MimeMultipart> mixedResponse = [];
    List<MimeMultipart> relatedResponse = [];

    // Completer. So we can wait for the two response results.
    Completer<bool> allDone = Completer<bool>();
    Completer<bool> relatedComplete = Completer<bool>();

    mm.listen((event) async {
      String contentType = event.headers["content-type"].toString();

      // If content-type is multipart/related, we need to reparse it with MimeMultiPartTransformer
      if (contentType.contains("multipart/related")) {
        List<List<int>> data = await event.toList();
        Stream<List<int>> myStream = Stream.fromIterable(data);

        final match = boundaryget.firstMatch(contentType);
        boundary = match?.group(1) as String;

        Stream<MimeMultipart> responseData =
            MimeMultipartTransformer(boundary).bind(myStream);

        responseData.listen((event) {
          // Add to relatedResponse
          relatedResponse.add(event);
        }, onDone: () => relatedComplete.complete(true), 
        onError: (er) => relatedComplete.complete(false));
      } else {
        // Add to mixedResponse
        mixedResponse.add(event);
      }
    }, onDone: () => allDone.complete(true), onError: (e) => allDone.complete(false));

    // Lets wait for the results...
    await relatedComplete.future;
    await allDone.future;

    // Here are the results.
    print("Mixed Response Length: " + mixedResponse.length.toString());
    print("Related Response Length: " + relatedResponse.length.toString());
    for (MimeMultipart response in mixedResponse) {
      print("Headers: " + response.headers.toString());
      List<String> body = await response.single
          .asStream()
          .map(((event) => utf8.decode(event, allowMalformed: true)))
          .toList();
      print("Content Body: " + body[0].toString());
    }
    for (MimeMultipart response in relatedResponse) {
      print(response.headers);
      List<String> body = await response.single
          .asStream()
          .map(((event) => utf8.decode(event, allowMalformed: true)))
          .toList();
      print("Content Body: " + body[0].toString());

      // That's all.
    }
  }

flutter: {x-couchdb-body-time: 0, x-couch-request-id: b2930f11cd, content-type: multipart/mixed; boundary="b9c676d8e38719f6db939e000e1584f4", transfer-encoding: chunked, date: Wed, 18 May 2022 20:08:11 GMT, server: CouchDB/3.2.0 (Erlang OTP/22)}
flutter: Mixed Response Length: 2
flutter: Related Response Length: 2
flutter: Headers: {content-type: application/json}
flutter: Content Body: {"_id":"patient/1001","_rev":"5-d1eea3934c7a179636ca3021e30615cf","_deleted":true}
flutter: Headers: {content-type: application/json; error="true"}
flutter: Content Body: {"missing":"2-logi"}
flutter: {content-type: application/json}
flutter: Content Body: {"_id":"patient/1001","_rev":"5-738ce01d9989bc16084b01572871d9e6","first_name":"Amees - Sun & Moon","_attachments":{"Screen Shot 2022-05-17 at 11.32.22 AM.png":{"content_type":"image/png","revpos":4,"digest":"md5-irm/EL7L1BiKmfimBIWLIw==","length":156857,"follows":true}}}
flutter: {content-disposition: attachment; filename="Screen Shot 2022-05-17 at 11.32.22 AM.png", content-type: image/png, content-length: 156857}
flutter: Content Body: �PNG
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