如何使用Java发出多部分/表单数据POST请求?


96

在Apache Commons HttpClient的3.x版本中,可以进行multipart / form-data POST请求(2004年的示例)。不幸的是,这在HttpClient的4.0版本中不再可行。

对于我们的核心活动“ HTTP”,多部分内容超出了范围。我们很乐意使用由其他项目维护的多部分代码,但我对此一无所知。几年前,我们曾尝试将多部分代码移至commons编解码器,但我没有离开那里。Oleg最近提到了另一个包含多部分解析代码的项目,并且可能对我们的多部分格式化代码感兴趣。我不知道目前的状态。(http://www.nabble.com/multipart-form-data-in-4.0-td14224819.html

是否有人知道有任何允许我编写可发出多部分/表单数据POST请求的HTTP客户端的Java库?

背景:我想使用Zoho WriterRemote API


Answers:


151

我们使用HttpClient 4.x进行多部分文件发布。

更新:从HttpClient 4.3开始,不推荐使用某些类。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();

以下是不推荐使用HttpClient 4.0 API的原始代码片段:

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();

62
嗯,多部分内容已移至org.apache.httpcomponents-httpmime-4.0!可以在某处提到:/

我尝试了更新的代码,该代码适用于小文件,但不适用于大文件。您能帮我解决这个问题

嗨,ZZ,我已经在代码中进行了上述更改,但是,我现在面临一个新问题-我的REST端点不接受该请求。期望使用以下参数:〜@ PathVariable最终字符串id,@ RequestParam(“ image”)最终MultipartFile图像,@ RequestParam(“ l”)最终字符串l,@ RequestParam(“ lo”)最终字符串lo,@ RequestParam(“ bac“)最终字符串bac,@ RequestParam(” cac“)最终字符串cac,@ RequestParam(” m“)最终字符串m ...以前,该请求已被接受。但是现在我收到500错误。任何想法为什么会发生这种情况?
洛根

我编辑了答案,以使代码示例不再水平滚动---当我尝试在自己的工作中使用滚动时,滚动导致我错过了重要的最终参数。
西尔维·戴维斯

这是更新答案<dependency> <groupId> org.apache.httpcomponents </ groupId> <artifactId> httpclient </ artifactId> <version> 4.3.6 </ version> </ dependency> <!- mvnrepository.com/artifact/org.apache.httpcomponents/httpmime- > <dependency> <groupId> org.apache.httpcomponents </ groupId> <artifactId> httpmime </ artifactId> <version> 4.3.6 </ version> < / dependency>
Wazime '17

39

这些是我的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依赖关系:

<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>

1
你需要的HttpCore为好,在4.2至少,对于HttpEntity
alalonde

18

如果JAR的大小很重要(例如在applet的情况下),则还可以直接将java.net.HttpURLConnection与httpmime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

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>

FileBody来自哪里?是否有不使用apace.httpcomponents的(简便)方法?

6

使用此代码可使用post方式将图片或任何其他文件上传到服务器。

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();
        }
    }

}

它需要以下文件上传。

库是 httpclient-4.1.2.jar, httpcore-4.1.2.jar, httpmime-4.1.2.jar, httpclient-cache-4.1.2.jar, commons-codec.jar并且 commons-logging-1.1.1.jar将在类路径中。


4

您还可以使用基于HTTP客户端构建的REST保证。很简单:

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

它将假定控件名称为“文件”。如果你有不同的控制名字,那么你需要指定它:multiPart("controlName", new File("/somedir/file.bin"))github.com/rest-assured/rest-assured/wiki/...
asmaier

REST Assured具有出色的API,并支持许多功能。使用它是一种乐趣。但公平地说,值得一提的是,由于某些预热程序,您可能会在首次通话时遇到性能下降的情况。您可能会发现在互联网上,即这里更多信息sqa.stackexchange.com/questions/39532/...
user1053510

REST Assured是一个出色的库,但是它是为Web API测试而设计的,我认为它不是在生产代码中进行HTTP调用的正确工具,尽管它当然使用了相同的基础库。
拉尼尔·威耶拉特尼

3

这是不需要任何库的解决方案。

此例程将目录中的每个文件传输d:/data/mpf10urlToConnect


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

2

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


2

我在Apache的快速入门指南中找到了此示例。适用于版本4.5:

/**
 * 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();
        }
    }
}

0

我们有一个纯Java的multipart-form提交实现,无需使用jdk之外的任何外部依赖项或库。请参阅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);
    }
}

0

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);
  }
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