Question

我想要一些帮助，澄清使用HttpAsyncClient和multipart实体。基本上我正在尝试使用HttpAsyncClient将文件（byte []）的内容上传为MultiPart Body。我如何使用它的示例：

    CloseableHttpAsyncClient httpAsyncClient = HttpAsyncClients.createDefault();
    httpAsyncClient.start();

    MultipartEntityBuilder reqEntity = MultipartEntityBuilder.create();
    reqEntity.addPart("file",new ByteArrayBody(Base64.decodeBase64(fileContent),"");
    reqEntity.addPart("fileSize",new StringBody("1234"));
    reqEntity.addPart("fileName",new StringBody("xyz.txt"));
    reqEntity.addPart("fileType",new StringBody("text/plain"));
    reqEntity.addPart("SEQ_NUM",new StringBody("23432"));

    HttpPost httppost = new HttpPost(endpointUrl);
    httppost.setEntity(reqEntity.build());

    Future<HttpResponse> future = httpAsyncClient.execute(httppost, null);
    httpAsyncClient.close();

以下是为此实施添加到项目中的Pom Dependences：

<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpasyncclient</artifactId>
  <version>4.0.2</version>
</dependency>
<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpmime</artifactId>
  <version>4.3.6</version>
</dependency>

现在，我被阻止在引发以下异常的地方：

java.util.concurrent.ExecutionException：java.lang.UnsupportedOperationException：Multipart表单实体未实现#getContent（）

我通过互联网进行了大量搜索，并且可以找到有关新的HttpAsyncClient实现的非常少的细节。我发现一些用户被问到类似的问题，但没有一个解决方案适合我。

[HttpAsyncClient多部分实体无法正常工作？] 在下面的链接中，用户建议使用BufferedHttpEntity包装MultipartEntity实例。所以，我更新了下面的代码（不确定它是否正确），但仍然是相同的异常。

    CloseableHttpAsyncClient httpAsyncClient = HttpAsyncClients.createDefault();
    httpAsyncClient.start();

    MultipartEntityBuilder reqEntity = MultipartEntityBuilder.create();
    reqEntity.addPart("file",new ByteArrayBody(Base64.decodeBase64(fileContent),"");
    reqEntity.addPart("fileSize",new StringBody("1234"));
    reqEntity.addPart("fileName",new StringBody("xyz.txt"));
    reqEntity.addPart("fileType",new StringBody("text/plain"));
    reqEntity.addPart("SEQ_NUM",new StringBody("23432"));

    HttpPost httppost = new HttpPost(endpointUrl);
    httppost.setEntity(new BufferedHttpEntity(reqEntity.build()));


    Future<HttpResponse> future = httpAsyncClient.execute(httppost, null);
    httpAsyncClient.close();

感谢您帮助确定原因。

参考文献：

http://mail-archives.apache.org/mod_mbox/hc-httpclient-users/201311.mbox/%3c13034392.132.1384195516775.JavaMail.Hal@Harold-Rosenbergs-MacBook-Pro.local%3e

http://mail-archives.apache.org/mod_mbox/hc-httpclient-users/201206.mbox/%3C1339240012.2405.12.camel@ubuntu%3E

Answer 1

不能异步使用MultipartFormEntity。其中一个选项是将实体写入ByteArrayOutputStream并从中创建NByteArrayEntity。

    File file = new File(filePath);
    ByteArrayBody body;
    body = new ByteArrayBody(FileUtils.readFileToByteArray(file), file.getName());

    HttpEntity mEntity = MultipartEntityBuilder.create()
            .setBoundary("-------------" + boundary)
            .addPart("file", body)
            .build();

    ByteArrayOutputStream baoStream = new ByteArrayOutputStream();      
    mEntity.writeTo(baoStream);

    HttpEntity nByteEntity = new NByteArrayEntity(baoStream.toByteArray(), ContentType.MULTIPART_FORM_DATA);
    httppost.setEntity(nByteEntity );

使用Multipart Entity实现HttpComponent的HttpAsyncClient

1 个答案: