如何使用 Java 发出 multipart/form-data POST 请求？

Question

在 Apache Commons HttpClient 版本 3.x 的日子里，发出 multipart/form-data POST 请求是可能的 (an example from 2004)。不幸的是，这在version 4.0 of HttpClient 中不再可能。

对于我们的核心活动“HTTP”，多部分有点 超出范围。我们很乐意使用由某些人维护的多部分代码 范围内的其他项目，但我不知道。 几年前，我们尝试将多部分代码移至 commons-codec 以前，但我没有在那里起飞。奥列格最近提到了另一个 具有多部分解析代码并且可能感兴趣的项目 在我们的多部分格式化代码中。不知道现在的状态 在那。 (http://www.nabble.com/multipart-form-data-in-4.0-td14224819.html)

是否有人知道任何 Java 库允许我编写可以发出多部分/表单数据 POST 请求的 HTTP 客户端？

背景：我想使用Remote API of Zoho Writer。

Answer 1

你会快乐的！

   <dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.13</version>
   </dependency>
   <dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpmime</artifactId>
    <version>4.3.1</version>
   </dependency>

import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.entity.mime.content.ByteArrayBody;


byte[] byteArr1 = multipartFile1.getBytes();
byte[] byteArr2 = multipartFile2.getBytes();

HttpEntity reqEntity = MultipartEntityBuilder.create().setCharset(Charset.forName("UTF-8"))
                .addPart("image1", new ByteArrayBody(byteArr1, req.getMultipartFile1().getOriginalFilename()))
                .addPart("image2", new ByteArrayBody(byteArr2, req.getMultipartFile2().getOriginalFilename()))
                .build();

Answer 2

使用 HttpRequestFactory 到 jira xray 的 /rest/raven/1.0/import/execution/cucumber/multipart ：

Map<String, Object> params = new HashMap<>();
            params.put( "info", "zigouzi" );
            params.put(  "result", "baalo"  );
            HttpContent content = new UrlEncodedContent(params);

            OAuthParameters oAuthParameters = jiraOAuthFactory.getParametersForRequest(ACCESS_TOKEN, CONSUMER_KEY, PRIVATE_KEY);
            HttpRequestFactory requestFactory = new NetHttpTransport().createRequestFactory(oAuthParameters);
            HttpRequest request = requestFactory.buildPostRequest(new GenericUrl(url),   content);
            request.getHeaders().setAccept("application/json");
            String boundary = Long.toHexString(System.currentTimeMillis());
            request.getHeaders().setContentType("multipart/form-data; boundary="+boundary);
            request.getHeaders().setContentEncoding("application/json");
            HttpResponse response = null ;
            try
            {
                response = request.execute();
                Scanner s = new Scanner(response.getContent()).useDelimiter("\\A");
                result = s.hasNext() ? s.next() : "";
            }
            catch (Exception e)
            {
                 
            }

成功了。

Answer 3

我的代码使用多部分中的 post 将文件发送到服务器。 请求发送表单数据时使用多值映射

  LinkedMultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
        map.add("FILE", new FileSystemResource(file));
        map.add("APPLICATION_ID", Number);

   httpService.post( map,headers);

在接收端使用

@RequestMapping(value = "fileUpload", method = RequestMethod.POST)
    public ApiResponse AreaCsv(@RequestParam("FILE") MultipartFile file,@RequestHeader("clientId") ){
//code
}

Answer 4

这是一个不需要任何库的解决方案。

此例程将目录d:/data/mpf10 中的每个文件传输到urlToConnect

String boundary = Long.toHexString(System.currentTimeMillis());
URLConnection connection = new URL(urlToConnect).openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
PrintWriter writer = null;
try {
    writer = new PrintWriter(new OutputStreamWriter(connection.getOutputStream(), "UTF-8"));
    File dir = new File("d:/data/mpf10");
    for (File file : dir.listFiles()) {
        if (file.isDirectory()) {
            continue;
        }
        writer.println("--" + boundary);
        writer.println("Content-Disposition: form-data; name=\"" + file.getName() + "\"; filename=\"" + file.getName() + "\"");
        writer.println("Content-Type: text/plain; charset=UTF-8");
        writer.println();
        BufferedReader reader = null;
        try {
            reader = new BufferedReader(new InputStreamReader(new FileInputStream(file), "UTF-8"));
            for (String line; (line = reader.readLine()) != null;) {
                writer.println(line);
            }
        } finally {
            if (reader != null) {
                reader.close();
            }
        }
    }
    writer.println("--" + boundary + "--");
} finally {
    if (writer != null) writer.close();
}
// Connection is lazily executed whenever you request any status.
int responseCode = ((HttpURLConnection) connection).getResponseCode();
// Handle response

Answer 5

我的代码将 multipartFile 发布到服务器。

  public static HttpResponse doPost(
    String host,
    String path,
    String method,
    MultipartFile multipartFile
  ) throws IOException
  {

    HttpClient httpClient = wrapClient(host);
    HttpPost httpPost = new HttpPost(buildUrl(host, path));

    if (multipartFile != null) {

      HttpEntity httpEntity;

      ContentBody contentBody;
      contentBody = new ByteArrayBody(multipartFile.getBytes(), multipartFile.getOriginalFilename());
      httpEntity = MultipartEntityBuilder.create()
                                         .addPart("nameOfMultipartFile", contentBody)
                                         .build();

      httpPost.setEntity(httpEntity);

    }
    return httpClient.execute(httpPost);
  }

Answer 6

我在 Apache 的 Quickstart Guide 中找到了 this sample。适用于 4.5 版：

/**
 * Example how to use multipart/form encoded POST request.
 */
public class ClientMultipartFormPost {

    public static void main(String[] args) throws Exception {
        if (args.length != 1)  {
            System.out.println("File path not given");
            System.exit(1);
        }
        CloseableHttpClient httpclient = HttpClients.createDefault();
        try {
            HttpPost httppost = new HttpPost("http://localhost:8080" +
                    "/servlets-examples/servlet/RequestInfoExample");

            FileBody bin = new FileBody(new File(args[0]));
            StringBody comment = new StringBody("A binary file of some kind", ContentType.TEXT_PLAIN);

            HttpEntity reqEntity = MultipartEntityBuilder.create()
                    .addPart("bin", bin)
                    .addPart("comment", comment)
                    .build();


            httppost.setEntity(reqEntity);

            System.out.println("executing request " + httppost.getRequestLine());
            CloseableHttpResponse response = httpclient.execute(httppost);
            try {
                System.out.println("----------------------------------------");
                System.out.println(response.getStatusLine());
                HttpEntity resEntity = response.getEntity();
                if (resEntity != null) {
                    System.out.println("Response content length: " + resEntity.getContentLength());
                }
                EntityUtils.consume(resEntity);
            } finally {
                response.close();
            }
        } finally {
            httpclient.close();
        }
    }
}

Answer 7

我们有一个多部分表单提交的纯 java 实现，不使用 jdk 之外的任何外部依赖项或库。参考https://github.com/atulsm/https-multipart-purejava/blob/master/src/main/java/com/atul/MultipartPure.java

private static String body = "{\"key1\":\"val1\", \"key2\":\"val2\"}";
private static String subdata1 = "@@ -2,3 +2,4 @@\r\n";
private static String subdata2 = "<data>subdata2</data>";

public static void main(String[] args) throws Exception{        
    String url = "https://" + ip + ":" + port + "/dataupload";
    String token = "Basic "+ Base64.getEncoder().encodeToString((userName+":"+password).getBytes());

    MultipartBuilder multipart = new MultipartBuilder(url,token);       
    multipart.addFormField("entity", "main", "application/json",body);
    multipart.addFormField("attachment", "subdata1", "application/octet-stream",subdata1);
    multipart.addFormField("attachment", "subdata2", "application/octet-stream",subdata2);        
    List<String> response = multipart.finish();         
    for (String line : response) {
        System.out.println(line);
    }
}

Answer 8

httpcomponents-client-4.0.1 为我工作。但是，我必须添加外部 jar apache-mime4j-0.6.jar (org.apache.james.mime4j) 否则 reqEntity.addPart("bin", bin); 不会编译。现在它就像魅力一样工作。

Answer 9

我们使用 HttpClient 4.x 进行多部分文件发布。

更新：从 HttpClient 4.3 开始，一些类已被弃用。这是带有新 API 的代码：

CloseableHttpClient httpClient = HttpClients.createDefault();
HttpPost uploadFile = new HttpPost("...");
MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.addTextBody("field1", "yes", ContentType.TEXT_PLAIN);

// This attaches the file to the POST:
File f = new File("[/path/to/upload]");
builder.addBinaryBody(
    "file",
    new FileInputStream(f),
    ContentType.APPLICATION_OCTET_STREAM,
    f.getName()
);

HttpEntity multipart = builder.build();
uploadFile.setEntity(multipart);
CloseableHttpResponse response = httpClient.execute(uploadFile);
HttpEntity responseEntity = response.getEntity();

以下是 已弃用的 HttpClient 4.0 API 的原始 sn-p 代码：

HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);

FileBody bin = new FileBody(new File(fileName));
StringBody comment = new StringBody("Filename: " + fileName);

MultipartEntity reqEntity = new MultipartEntity();
reqEntity.addPart("bin", bin);
reqEntity.addPart("comment", comment);
httppost.setEntity(reqEntity);

HttpResponse response = httpclient.execute(httppost);
HttpEntity resEntity = response.getEntity();

Answer 10

使用此代码将图像或任何其他文件上传到使用多部分发布的服务器。

import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;

import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.entity.mime.content.FileBody;
import org.apache.http.entity.mime.content.StringBody;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;

public class SimplePostRequestTest {

    public static void main(String[] args) throws UnsupportedEncodingException, IOException {
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://192.168.0.102/uploadtest/upload_photo");

        try {
            FileBody bin = new FileBody(new File("/home/ubuntu/cd.png"));
            StringBody id = new StringBody("3");
            MultipartEntity reqEntity = new MultipartEntity();
            reqEntity.addPart("upload_image", bin);
            reqEntity.addPart("id", id);
            reqEntity.addPart("image_title", new StringBody("CoolPic"));

            httppost.setEntity(reqEntity);
            System.out.println("Requesting : " + httppost.getRequestLine());
            ResponseHandler<String> responseHandler = new BasicResponseHandler();
            String responseBody = httpclient.execute(httppost, responseHandler);
            System.out.println("responseBody : " + responseBody);

        } catch (ClientProtocolException e) {

        } finally {
            httpclient.getConnectionManager().shutdown();
        }
    }

}

它需要以下文件才能上传。

图书馆是 httpclient-4.1.2.jar, httpcore-4.1.2.jar, httpmime-4.1.2.jar, httpclient-cache-4.1.2.jar, commons-codec.jar 和 commons-logging-1.1.1.jar 在类路径中。

Answer 11

如果 JAR 的大小很重要（例如，在 applet 的情况下），也可以直接将 httpmime 与 java.net.HttpURLConnection 一起使用，而不是 HttpClient。

httpclient-4.2.4:      423KB
httpmime-4.2.4:         26KB
httpcore-4.2.4:        222KB
commons-codec-1.6:     228KB
commons-logging-1.1.1:  60KB
Sum:                   959KB

httpmime-4.2.4:         26KB
httpcore-4.2.4:        222KB
Sum:                   248KB

代码：

HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");

FileBody fileBody = new FileBody(new File(fileName));
MultipartEntity multipartEntity = new MultipartEntity(HttpMultipartMode.STRICT);
multipartEntity.addPart("file", fileBody);

connection.setRequestProperty("Content-Type", multipartEntity.getContentType().getValue());
OutputStream out = connection.getOutputStream();
try {
    multipartEntity.writeTo(out);
} finally {
    out.close();
}
int status = connection.getResponseCode();
...

pom.xml 中的依赖关系：

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpmime</artifactId>
    <version>4.2.4</version>
</dependency>

Answer 12

您还可以使用基于 HTTP 客户端的REST Assured。很简单：

given().multiPart(new File("/somedir/file.bin")).when().post("/fileUpload");

Answer 13

这些是我拥有的 Maven 依赖项。

Java 代码：

HttpClient httpclient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);

FileBody uploadFilePart = new FileBody(uploadFile);
MultipartEntity reqEntity = new MultipartEntity();
reqEntity.addPart("upload-file", uploadFilePart);
httpPost.setEntity(reqEntity);

HttpResponse response = httpclient.execute(httpPost);

pom.xml 中的 Maven 依赖项：

<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpclient</artifactId>
  <version>4.0.1</version>
  <scope>compile</scope>
</dependency>
<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpmime</artifactId>
  <version>4.0.1</version>
  <scope>compile</scope>
</dependency>