Java MultiPart帖子

Question

我正在尝试使用以下正文创建到URL的多部分帖子：

Content-Disposition: form-data; name="json"
Content-Type: "application/json; charset=UTF-8"

{"input1":"data1","input2":"data2","input3":"data3"}

--APIMultipartPost
Content-Disposition: form-data; name="filePath"; filename="myFile.dat"
Content-Length: 381645
Content-Type: text/plain
Content-Transfer-Encoding: binary

<!-- SNIP -->
<!-- The OWL file was included here in plain text (without the SNIPs) -->
<!-- SNIP -->

我尝试使用MultipartEntityBuilder创建多部分帖子，但是可能参数做错了。 有人可以为我提供这篇文章的Java代码吗？

这是我的代码：

CloseableHttpClient httpClient = HttpClients.createDefault();
HttpPost uploadFile = new HttpPost(URL);

MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.addTextBody("input1", "data1");
builder.addTextBody("input2", "data2");
builder.addTextBody("input3", "data3");

builder.addBinaryBody("file", new File("C:/myFile.dat"), ContentType.APPLICATION_OCTET_STREAM, "myFile.dat");
HttpEntity multipart = builder.build();
uploadFile.setEntity(multipart);
HttpResponse response = httpClient.execute(uploadFile);

和我得到的错误：

HttpResponseProxy{HTTP/1.1 422 Unprocessable Entity [Server: nginx/1.6.0, Date: Wed, 28 Jan 2015 19:29:42 GMT, Content-Type: application/json;charset=utf-8, Content-Length: 89, Connection: keep-alive, Status: 422 Unprocessable Entity, X-Rack-Cache: invalidate, pass, X-Content-Type-Options: nosniff] ResponseEntityProxy{[Content-Type: application/json;charset=utf-8,Content-Length: 89,Chunked: false]}}

谢谢！

Answer 1

响应422无法处理的实体说

422（不可处理实体）状态代码表示服务器了解请求实体的内容类型（因此415（不支持的媒体类型）状态代码不合适），并且请求实体的语法正确（因此400（错误请求） ）状态代码不合适），但无法处理其中的说明。 例如，如果XML请求主体包含格式正确（即，语法正确）但语义错误的XML指令，则可能发生此错误情况。

因此，您可以看到发送的请求与POST所针对的控制器/服务的规范不符。 如果使用TCPMon之类的工具，则实际上可以拦截发送的请求并检查其外观。 当我用您的代码执行时，它看起来像

POST /url HTTP/1.1
Content-Length: 739
Content-Type: multipart/form-data; boundary=L2EqtNqIEXOWRCYYrYH8FSP1JAD65wz6c
Host: 127.0.0.1:8090
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.3.6 (java 1.5)
Accept-Encoding: gzip,deflate

--L2EqtNqIEXOWRCYYrYH8FSP1JAD65wz6c
Content-Disposition: form-data; name="input1"
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit

data1
--L2EqtNqIEXOWRCYYrYH8FSP1JAD65wz6c
Content-Disposition: form-data; name="input2"
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit

data2
--L2EqtNqIEXOWRCYYrYH8FSP1JAD65wz6c
Content-Disposition: form-data; name="input3"
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit

data3
--L2EqtNqIEXOWRCYYrYH8FSP1JAD65wz6c
Content-Disposition: form-data; name="file"; filename="myFile.dat"
Content-Type: application/octet-stream
Content-Transfer-Encoding: binary


--L2EqtNqIEXOWRCYYrYH8FSP1JAD65wz6c--

这不是你想要的。 您只需要一个包含两部分的请求，一个是json数据，另一个是文件。

因此，如果您按以下方式更改代码。

CloseableHttpClient httpClient = HttpClients.createDefault();
HttpPost uploadFile = new HttpPost("http://localhost:8090/1");

MultipartEntityBuilder builder = MultipartEntityBuilder.create();
String jsonStr = "{\"input1\":\"data1\",\"input2\":\"data2\",\"input3\":\"data3\"}";
builder.addTextBody("json", jsonStr, ContentType.APPLICATION_JSON);
builder.addBinaryBody("file", new File("/path/to/file"),
        ContentType.TEXT_PLAIN, "myFile.dat");

HttpEntity multipart = builder.build();
uploadFile.setEntity(multipart);
HttpResponse response = httpClient.execute(uploadFile);

您可以提供如下请求。

POST /url HTTP/1.1
Content-Length: 468
Content-Type: multipart/form-data; boundary=mN_bWsS4QQnlPJksvinB_WUpl2Qi6zVVElUEEBKh
Host: 127.0.0.1:8090
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.3.6 (java 1.5)
Accept-Encoding: gzip,deflate

--mN_bWsS4QQnlPJksvinB_WUpl2Qi6zVVElUEEBKh
Content-Disposition: form-data; name="json"
Content-Type: application/json; charset=UTF-8
Content-Transfer-Encoding: 8bit

{"input1":"data1","input2":"data2","input3":"data3"}
--mN_bWsS4QQnlPJksvinB_WUpl2Qi6zVVElUEEBKh
Content-Disposition: form-data; name="file"; filename="myFile.dat"
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: binary


--mN_bWsS4QQnlPJksvinB_WUpl2Qi6zVVElUEEBKh--

这就是您所需要的。

Answer 2

对于多部分请求，内容类型必须是multipart / form-data，然后为每个内容指定内容类型。 您可能要参考w3.org- HTTP标头示例的表单介绍 。