Java MultiPart帖子

Question

我正在尝试创建一个包含多个部分的帖子，其内容如下：

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post，但可能对参数做了错误的操作。有人能帮我写这篇文章的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);

我所犯的错误是：

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个不可处理实体表示

422 (非处理实体)状态代码意味着服务器理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是正确的(因此400 (坏请求)状态代码不合适)，但无法处理所包含的指令。例如，如果XML请求体包含格式良好(即语法正确)但语义错误的XML指令，则可能出现此错误情况。

因此，如您所见，您发送的请求不符合您发布的控制器/服务的规范。如果您使用像TCPMon这样的工具，您实际上可以拦截发送的请求，并检查它的外观。当我用你的代码做这件事时，看起来就像

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。您只需要包含两个部分的请求，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);

可以提供如下所示的请求。

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--

这正是你所需要的。

Answer 2

对于多部分请求，内容类型必须是多部分/表单数据，然后为每个内容指定内容类型。对于header示例，您可能需要参考w3.org -表单简介。