我试图上传文件到一个网址，并已收到，而不是常规的JSON字符串响应，只有ResponseEntityProxy{[Content-Type: application/json;charset=UTF-8,Chunked: true]}。正如我所理解的，有一个JSON字符串作为响应，我需要以某种方式提取它。
下面是我的代码，我已经尝试到目前为止做（这是在我上传文件到url的方法中）：

public String uploadDocument() {
    
    String responseMsg="empty";
     
    try(CloseableHttpClient client = HttpClients.createDefault()){
    
        HttpPost httpPost = new HttpPost(SupportUtil.WHATSAPP_PUSH_BASEURL+"/media/upload/");
        httpPost.addHeader("Content-type", "application/octet-stream");
        httpPost.addHeader("Authorization", "Bearer " + SupportUtil.WHATSAPP_PUSH_KEY);
        
        File file=null;
        try {
            file = ResourceUtils.getFile("/home/ubuntu/DanFagin.pdf");
        } catch (FileNotFoundException e2) {
            
            e2.printStackTrace();
        }
        
        MultipartEntityBuilder builder = MultipartEntityBuilder.create();
        builder.addBinaryBody("file",file,ContentType.APPLICATION_OCTET_STREAM,"DanFagin.pdf");
        
        org.apache.http.HttpEntity multipart = builder.build();
        httpPost.setEntity(multipart);

        try (CloseableHttpResponse response = client.execute(httpPost)) {
            
            System.out.println(response.getEntity().toString());
            responseMsg= EntityUtils.toString(response.getEntity(),"UTF-8");
            System.out.println(responseMsg);
            
        } catch (ClientProtocolException e) {
            
            e.printStackTrace();
        } catch (IOException e) {
            
            e.printStackTrace();
        }
    
        System.out.println("Response is closed");
        System.out.println(responseMsg);
        
     } catch (IOException e1) {
        
        e1.printStackTrace();
    }
       
    System.out.println("Client is closed");
    return responseMsg;
    
}

字符串
因此，在上面的代码中，我已经构建了HttpResponse的实体，然后尝试使用EntityUtils.toString(entity)方法来获取实体的内容。但是当我使用该方法时，我得到以下错误：

org.apache.http.ConnectionClosedException: Premature end of chunk coded message body: closing chunk expected
    at org.apache.http.impl.io.ChunkedInputStream.getChunkSize(ChunkedInputStream.java:263)
    at org.apache.http.impl.io.ChunkedInputStream.nextChunk(ChunkedInputStream.java:222)
    at org.apache.http.impl.io.ChunkedInputStream.read(ChunkedInputStream.java:183)
    at org.apache.http.conn.EofSensorInputStream.read(EofSensorInputStream.java:135)
    at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
    at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
    at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
    at java.io.InputStreamReader.read(InputStreamReader.java:184)
    at java.io.Reader.read(Reader.java:140)
    at org.apache.http.util.EntityUtils.toString(EntityUtils.java:227)
    at org.apache.http.util.EntityUtils.toString(EntityUtils.java:270)
    at org.apache.http.util.EntityUtils.toString(EntityUtils.java:290)
    at com.wingsure.WSWhatsapp.repository.RestTemplateImpl.uploadDocument(RestTemplateImpl.java:564)
    at com.wingsure.WSWhatsapp.service.RestTemplateService.uploadDocument(RestTemplateService.java:49)
    at com.wingsure.WSWhatsapp.repository.WebHookRepository.getWebHookDetails(WebHookRepository.java:60)
    at com.wingsure.WSWhatsapp.service.ProductService.getWebHookDetails(ProductService.java:84)
    at com.wingsure.WSWhatsapp.controller.ProductController.getWebHookDetails(ProductController.java:57)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
etc

型
第564行是EntityUtils.toString()方法所在的位置，如果没有它，我不会收到任何错误。在另一边，没有找到任何其他方式如何可以获得实体的内容，即. JSON字符串，不使用EntityUtils.toString()方法。
有人知道这里有什么问题吗？我将非常感谢任何帮助和建议。谢谢你在每一个案件。