将pdf传递给Salesforce中的IBM watson时出现"415:Media not supported“错误

Question

我计划将IBM Watson文档转换服务与Salesforce集成。

从那里我无法将我的pdf文件直接发送到Watson，而我得到的是Media Type not supported。

我也得到了这个错误：

{
  "code" : 500 ,
  "error" : "Server Error" ,
  "description" : "2017-07-18T06:02:19-04:00, Error WATSNGWERR-0x0113001c occurred when accessing https://gateway.watsonplatform.net/document-conversion/api/v1/convert_document?version=2015-12-15&config="{"conversion_target":"answer_units"}", Tran-Id: gateway-dp02-1967135880 - Watson Gateway Error"
}  

下面是我使用的代码：

public class Resume {
  String boundary = '----------------------------741e90d31eff';

  public string id{get;set;}
  public string content{get;set;}
  Transient public Attachment att{set;get;}

  public Resume(ApexPages.StandardController controller) {
    id=ApexPages.currentPage().getParameters().get('id');
    att=new Attachment();
    att=[Select Id,ParentId, Name,body,ContentType From Attachment where ParentId=:id limit 1];
    content=String.valueOf(att.body);

    System.debug('---->' + content);
    String header = '--' + boundary + '\nContent-Disposition: form-data; name="att"; filename="'+att.name+'";\nContent-Type: application/pdf';
    String footer = '--' + boundary + '--';
    String headerEncoded =
    EncodingUtil.base64Encode(Blob.valueOf(header+'\r\n\r\n'));
    String bodyEncoded = EncodingUtil.base64Encode(att.body);
    Blob bodyBlob = null;
    String last4Bytes =
    bodyEncoded.substring(bodyEncoded.length() - 4, bodyEncoded.length());
    while (headerEncoded.endsWith('=')){
      header+=' ';
      headerEncoded = EncodingUtil.base64Encode(Blob.valueOf(header+'\r\n\r\n'));
    }

    if (last4Bytes.endsWith('==')) {
      last4Bytes = last4Bytes.substring(0,2) + '0K';
      bodyEncoded = bodyEncoded.substring(0,bodyEncoded.length()-4) + last4Bytes;
      String footerEncoded = EncodingUtil.base64Encode(Blob.valueOf(footer));
      bodyBlob = EncodingUtil.base64Decode(headerEncoded + bodyEncoded + footerEncoded);
    } else if (last4Bytes.endsWith('=')) {
      last4Bytes = last4Bytes.substring(0,3) + 'N';
      bodyEncoded = bodyEncoded.substring(0,bodyEncoded.length()-4) + last4Bytes;
      footer = '\n' + footer;
      String footerEncoded = EncodingUtil.base64Encode(Blob.valueOf(footer));
      bodyBlob = EncodingUtil.base64Decode(headerEncoded + bodyEncoded + footerEncoded);
    } else {
      footer = '\r\n' + footer;
      String footerEncoded = EncodingUtil.base64Encode(Blob.valueOf(footer));
      bodyBlob = EncodingUtil.base64Decode(headerEncoded + bodyEncoded + footerEncoded);
    }

    String configAsString ='\"conversion_target:answer_units\"';
    Http h = new Http();
    HttpRequest request = new HttpRequest();
    request.setMethod('POST');
    request.setHeader('Content-Type','multipart/form-data; boundary=' + boundary);

    String username= 'DOCUMENT-CONVERSION-USERNAME';
    String password= 'DOCUMENT-CONVERSION-PASSWORD';
    request.setHeader('Authorization', 'Basic ' + EncodingUtil.base64Encode(blob.valueOf(username + ':' + password)));

    request.setEndpoint('https://gateway.watsonplatform.net/document-conversion/api/v1/convert_document?version=2015-12-15&config='+configAsString);
    request.setBodyAsBlob(bodyBlob);
    request.setCompressed(true);
    HttpResponse response = h.send(request);
    System.debug(response.getBody());
  }
}

Answer 1

您将config作为查询参数发送，但它应该在正文中。

下面是curl命令，它实现了您正在尝试执行的操作：

curl -X POST \
  -u "{username}":"{password}" \
  -F config="{\"conversion_target\":\"answer_units\"}" \
  -F "file=@sample.pdf;type=application/pdf" \
"https://gateway.watsonplatform.net/document-conversion/api/v1/convert_document?version=2015-12-15"

我也认为你创建正文的方式有一个错误。我的团队构建了一个SDK，以便在Salesforce环境中使用Watson API。我建议你看一看。

如果您不能将SDK部署到您的Salesforce组织(这是大量代码)，请从IBMWatsonMultipartBody.cls类复制代码。它将帮助您将Attachment编码为base64，以便您可以将其结束为Watson。

更新：文档转换服务已弃用，但该服务的功能已得到增强并迁移到Discovery service