Java HTTP Post Multipart

Question

我正在尝试用JAVA向本地服务器发送一个HTTP Post多部分请求。我正在尝试发送以下内容：

{
 "content-disposition": "form-data; name=\"metadata\"",
"content-type": "application/x-dmas+json",
 "body":         JSON.stringify(client_req)
},
{
"content-disposition": "attachment; filename=\"" + file + "\"; name=\"file\"",
"content-type": "application/octet-stream",
 "body":         [file content]
}

我研究过Apache HTTP组件，但它不允许我为每个部分指定内容类型和部署。下面是我使用Apache HTTP API用JAVA编写的代码：

` `CloseableHttpClient = HttpClients.createDefault()；

    try {
        HttpPost httppost = new HttpPost("IP");

        FileBody bin = new FileBody(new File(args[0]), "application/octet-stream");
        StringBody hash = new StringBody("{\"hash\": \"\", \"policy\": {\"retention_permitted\": true, \"distribution\": \"global\"}}", ContentType.create("application/x-dmas+json"));

        HttpEntity reqEntity = MultipartEntityBuilder.create()
                .addPart("metadata", hash)
                .addPart("file", bin)
                .build();


        httppost.setEntity(reqEntity);

`

Answer 1

FilePart和StringPart的构造函数参数和方法提供了此信息，您可以使用这两个参数和方法组成构成多部分请求的Part[]。

Answer 2

也许为时已晚，但对于任何寻找相同问题答案的人来说，作为参考，MultipartEntityBuilder类中有几个方法允许您为每个部分设置内容类型和内容部署。例如,

• addBinaryBody(String名称，文件文件，文本文件，字符串文本名称，字符串文本，contentType contentType)

如果我们在您的示例中使用上述方法，

CloseableHttpClient httpClient = HttpClients.createDefault();
HttpPost uploadFile = new HttpPost("http://url-to-post/");

MultipartEntityBuilder builder = MultipartEntityBuilder.create();
String jsonStr = "{\"hash\": \"\", \"policy\": {\"retention_permitted\": true, \"distribution\": \"global\"}}";
builder.addTextBody("metadata", jsonStr, ContentType.create("application/x-dmas+json"));
builder.addBinaryBody("file", new File("/path/to/file"),
    ContentType.APPLICATION_OCTET_STREAM, "filename");

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