Java streamify JSON对象并将其作为流[NodeJS]发送

我正在使用

requestpromise

npm库从NodeJS应用程序向javajersey 2.0api后端发出多部分请求。由于

request

使用

formdata

lib进行调用，我发现它只能发送字符串、缓冲区和流

在java后端，我希望POJO对象作为

@FormDataParam

s：

@GET
@ApiOperation(
        value = "Gets party metadata by party_id",
        notes = "Gets party metadata by party_id"
)
@ApiResponses(value = {
        @ApiResponse(code = 200, message = "metadata")
})
@Path("party")
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Metadata getByPartyId(
        @ApiParam(value = "partyId", required = true) @NotNull @QueryParam("partyId") String partyId,
        @ApiParam(value = "party metadata", required = true) @FormDataParam("metadata") Metadata metadata

) {
    return folderCtrl.getByPartyId(partyId);
}

在一些端点，我甚至等待多个POJO对象出现，并且在接收到端点时使用注释验证机制对它们进行验证。 到目前为止，我能够模拟所需的行为，因为我将这些POJO作为包含JSON数据的文件发送。Jersey/Jackson能够将其转换为POJO，并在其生命周期中继续

现在，我需要从NodeJS调用这些端点。 因此，我知道了可以通过

表单数据发送什么内容

，我想我需要一个选项来将JSON对象转换为流，并像前面的场景一样发送它以接收POJO对象

所以我的问题是，如何“流线化”NodeJ中的对象，并使用

请求承诺发送它们

这就是我现在拥有的：

'use strict';

var rp = require('request-promise');
var express = require('express');
var fs = require('fs');
var metaJson = require(__dirname + '/attachments/metadata.json');

var router = express.Router();

const Readable = require('readable-stream').Readable;

const stream = Readable({objectMode: true});
stream._read = () => {};

const PROTOCOL = 'http://';
const HOST = 'localhost:';
const PORT = 8080;

// define the home page route
router.get('/', async function (req, res) {

    stream.push(metaJson);

    const options = {
        method: req.method,
        json: true,
        baseUrl: PROTOCOL + HOST + PORT,
        uri: req.originalUrl,
        qs: {
            partyId: "qwer"
        },
        formData: {
            metadata: stream
        },
    };
      try {
          const response = await rp(options);
      } catch (err) {
          console.log(err);
      }


    res.send('foo res');
});

但最终会出现这样的错误：

    _http_outgoing.js:502
    throw new TypeError('First argument must be a string or Buffer');
    ^

TypeError: First argument must be a string or Buffer
    at ClientRequest.write (_http_outgoing.js:502:11)
    at Request.write (/home/tepo/IdeaProjects/rig/node_modules/request/request.js:1514:27)
    at FormData.ondata (internal/streams/legacy.js:16:26)
    at emitOne (events.js:96:13)
    at FormData.emit (events.js:191:7)
    at FormData.CombinedStream.write (/home/tepo/IdeaProjects/rig/node_modules/combined-stream/lib/combined_stream.js:118:8)
    at DelayedStream.ondata (internal/streams/legacy.js:16:26)
    at emitOne (events.js:96:13)
    at DelayedStream.emit (events.js:191:7)
    at DelayedStream._handleEmit (/home/tepo/IdeaProjects/rig/node_modules/delayed-stream/lib/delayed_stream.js:82:15)
    at Readable.source.emit (/home/tepo/IdeaProjects/rig/node_modules/delayed-stream/lib/delayed_stream.js:29:19)
    at Readable.read (/home/tepo/IdeaProjects/rig/node_modules/readable-stream/lib/_stream_readable.js:386:26)
    at flow (/home/tepo/IdeaProjects/rig/node_modules/readable-stream/lib/_stream_readable.js:734:34)
    at resume_ (/home/tepo/IdeaProjects/rig/node_modules/readable-stream/lib/_stream_readable.js:717:3)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)

---

当您在NodeJs中使用Express处理文件时，不要忘记使用“Multer”模块（已从Express中删除），该模块用于处理Express中的文件？