由于Android开发人员recommend使用HttpURLConnection类，我想知道是否有人能为我提供一个关于如何发送位图“文件”（实际上是内存中的流）的好例子）通过POST到Apache HTTP服务器。我对cookie或身份验证或任何复杂的东西不感兴趣，但我只想拥有一个可靠的逻辑实现。我在这里看到的所有例子看起来更像是“让我们试试这个，也许它有用”。
现在，我有这段代码：
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL("http://example.com/server.cgi");
urlConnection = (HttpURLConnection) url.openConnection();
} catch (Exception e) {
this.showDialog(getApplicationContext(), e.getMessage());
}
finally {
if (urlConnection != null)
{
urlConnection.disconnect();
}
}
showDialog应该只显示AlertDialog（如果网址无效？）。
现在，假设我在Bitmap image = this.getBitmap()派生的控件中生成如此位图：View，我想通过POST发送它。实现这样的事情的正确程序是什么？我需要使用哪些课程？我可以像this example一样使用HttpPost吗？如果是这样，我将如何为我的位图构建InputStreamEntity？我觉得要首先将位图存储在设备上的文件中是令人反感的。
我还应该提一下，我真的需要将原始位图的每个未经改变的像素发送到服务器，因此我无法将其转换为JPEG。
答案 0 :(得分：183)
我不知道为什么HttpURLConnection类没有提供任何发送文件的方法而不必手动编写文件包装器。这是我最终做的事情，但如果有人知道更好的解决方案，请告诉我。
输入数据：
Bitmap bitmap = myView.getBitmap();
静态东西：
String attachmentName = "bitmap";
String attachmentFileName = "bitmap.bmp";
String crlf = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
设置请求：
HttpURLConnection httpUrlConnection = null;
URL url = new URL("http://example.com/server.cgi");
httpUrlConnection = (HttpURLConnection) url.openConnection();
httpUrlConnection.setUseCaches(false);
httpUrlConnection.setDoOutput(true);
httpUrlConnection.setRequestMethod("POST");
httpUrlConnection.setRequestProperty("Connection", "Keep-Alive");
httpUrlConnection.setRequestProperty("Cache-Control", "no-cache");
httpUrlConnection.setRequestProperty(
"Content-Type", "multipart/form-data;boundary=" + this.boundary);
启动内容包装器：
DataOutputStream request = new DataOutputStream(
httpUrlConnection.getOutputStream());
request.writeBytes(this.twoHyphens + this.boundary + this.crlf);
request.writeBytes("Content-Disposition: form-data; name=\"" +
this.attachmentName + "\";filename=\"" +
this.attachmentFileName + "\"" + this.crlf);
request.writeBytes(this.crlf);
将Bitmap转换为ByteBuffer：
//I want to send only 8 bit black & white bitmaps
byte[] pixels = new byte[bitmap.getWidth() * bitmap.getHeight()];
for (int i = 0; i < bitmap.getWidth(); ++i) {
for (int j = 0; j < bitmap.getHeight(); ++j) {
//we're interested only in the MSB of the first byte,
//since the other 3 bytes are identical for B&W images
pixels[i + j] = (byte) ((bitmap.getPixel(i, j) & 0x80) >> 7);
}
}
request.write(pixels);
结束内容包装器：
request.writeBytes(this.crlf);
request.writeBytes(this.twoHyphens + this.boundary +
this.twoHyphens + this.crlf);
刷新输出缓冲区：
request.flush();
request.close();
获得回复：
InputStream responseStream = new
BufferedInputStream(httpUrlConnection.getInputStream());
BufferedReader responseStreamReader =
new BufferedReader(new InputStreamReader(responseStream));
String line = "";
StringBuilder stringBuilder = new StringBuilder();
while ((line = responseStreamReader.readLine()) != null) {
stringBuilder.append(line).append("\n");
}
responseStreamReader.close();
String response = stringBuilder.toString();
关闭回复流：
responseStream.close();
关闭连接：
httpUrlConnection.disconnect();
PS：当然我必须在private class AsyncUploadBitmaps extends AsyncTask<Bitmap, Void, String>中包装请求，以使Android平台满意，因为它不喜欢在主线程上有网络请求。
答案 1 :(得分：64)
我实际上找到了一种使用MultipartEntity使用HttpURLConnection发送文件的更好方法
private static String multipost(String urlString, MultipartEntity reqEntity) {
try {
URL url = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(10000);
conn.setConnectTimeout(15000);
conn.setRequestMethod("POST");
conn.setUseCaches(false);
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setRequestProperty("Connection", "Keep-Alive");
conn.addRequestProperty("Content-length", reqEntity.getContentLength()+"");
conn.addRequestProperty(reqEntity.getContentType().getName(), reqEntity.getContentType().getValue());
OutputStream os = conn.getOutputStream();
reqEntity.writeTo(conn.getOutputStream());
os.close();
conn.connect();
if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
return readStream(conn.getInputStream());
}
} catch (Exception e) {
Log.e(TAG, "multipart post error " + e + "(" + urlString + ")");
}
return null;
}
private static String readStream(InputStream in) {
BufferedReader reader = null;
StringBuilder builder = new StringBuilder();
try {
reader = new BufferedReader(new InputStreamReader(in));
String line = "";
while ((line = reader.readLine()) != null) {
builder.append(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return builder.toString();
}
假设您正在上传包含位图数据的图片：
Bitmap bitmap = ...;
String filename = "filename.png";
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, bos);
ContentBody contentPart = new ByteArrayBody(bos.toByteArray(), filename);
MultipartEntity reqEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);
reqEntity.addPart("picture", contentPart);
String response = multipost("http://server.com", reqEntity);
而且瞧！您的帖子数据将包含图片字段以及服务器上的文件名和路径。
答案 2 :(得分：55)
使用MultipartUtility以简单的方式使用某个参数上传服务器上的文件。
MultipartUtility.java
public class MultipartUtility {
private final String boundary;
private static final String LINE_FEED = "\r\n";
private HttpURLConnection httpConn;
private String charset;
private OutputStream outputStream;
private PrintWriter writer;
/**
* This constructor initializes a new HTTP POST request with content type
* is set to multipart/form-data
*
* @param requestURL
* @param charset
* @throws IOException
*/
public MultipartUtility(String requestURL, String charset)
throws IOException {
this.charset = charset;
// creates a unique boundary based on time stamp
boundary = "===" + System.currentTimeMillis() + "===";
URL url = new URL(requestURL);
Log.e("URL", "URL : " + requestURL.toString());
httpConn = (HttpURLConnection) url.openConnection();
httpConn.setUseCaches(false);
httpConn.setDoOutput(true); // indicates POST method
httpConn.setDoInput(true);
httpConn.setRequestProperty("Content-Type",
"multipart/form-data; boundary=" + boundary);
httpConn.setRequestProperty("User-Agent", "CodeJava Agent");
httpConn.setRequestProperty("Test", "Bonjour");
outputStream = httpConn.getOutputStream();
writer = new PrintWriter(new OutputStreamWriter(outputStream, charset),
true);
}
/**
* Adds a form field to the request
*
* @param name field name
* @param value field value
*/
public void addFormField(String name, String value) {
writer.append("--" + boundary).append(LINE_FEED);
writer.append("Content-Disposition: form-data; name=\"" + name + "\"")
.append(LINE_FEED);
writer.append("Content-Type: text/plain; charset=" + charset).append(
LINE_FEED);
writer.append(LINE_FEED);
writer.append(value).append(LINE_FEED);
writer.flush();
}
/**
* Adds a upload file section to the request
*
* @param fieldName name attribute in <input type="file" name="..." />
* @param uploadFile a File to be uploaded
* @throws IOException
*/
public void addFilePart(String fieldName, File uploadFile)
throws IOException {
String fileName = uploadFile.getName();
writer.append("--" + boundary).append(LINE_FEED);
writer.append(
"Content-Disposition: form-data; name=\"" + fieldName
+ "\"; filename=\"" + fileName + "\"")
.append(LINE_FEED);
writer.append(
"Content-Type: "
+ URLConnection.guessContentTypeFromName(fileName))
.append(LINE_FEED);
writer.append("Content-Transfer-Encoding: binary").append(LINE_FEED);
writer.append(LINE_FEED);
writer.flush();
FileInputStream inputStream = new FileInputStream(uploadFile);
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.flush();
inputStream.close();
writer.append(LINE_FEED);
writer.flush();
}
/**
* Adds a header field to the request.
*
* @param name - name of the header field
* @param value - value of the header field
*/
public void addHeaderField(String name, String value) {
writer.append(name + ": " + value).append(LINE_FEED);
writer.flush();
}
/**
* Completes the request and receives response from the server.
*
* @return a list of Strings as response in case the server returned
* status OK, otherwise an exception is thrown.
* @throws IOException
*/
public String finish() throws IOException {
StringBuffer response = new StringBuffer();
writer.append(LINE_FEED).flush();
writer.append("--" + boundary + "--").append(LINE_FEED);
writer.close();
// checks server's status code first
int status = httpConn.getResponseCode();
if (status == HttpURLConnection.HTTP_OK) {
BufferedReader reader = new BufferedReader(new InputStreamReader(
httpConn.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
response.append(line);
}
reader.close();
httpConn.disconnect();
} else {
throw new IOException("Server returned non-OK status: " + status);
}
return response.toString();
}
}
upload file String charset = "UTF-8";
String requestURL = "YOUR_URL";
MultipartUtility multipart = new MultipartUtility(requestURL, charset);
multipart.addFormField("param_name_1", "param_value");
multipart.addFormField("param_name_2", "param_value");
multipart.addFormField("param_name_3", "param_value");
multipart.addFilePart("file_param_1", new File(file_path));
String response = multipart.finish(); // response from server.
以及参数。
注意：将此代码放在非ui-thread中以获得响应。
LeakCanary.install(this);
答案 3 :(得分：9)
Jaydipsinh Zala 的解决方案对我不起作用，我不知道为什么但它似乎接近解决方案。
所以将这个与 Mihai Todor 的伟大解决方案和解释合并，结果就是这个课程目前适合我。如果它可以帮助某人：
MultipartUtility2V.java
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.file.Files;
public class MultipartUtilityV2 {
private HttpURLConnection httpConn;
private DataOutputStream request;
private final String boundary = "*****";
private final String crlf = "\r\n";
private final String twoHyphens = "--";
/**
* This constructor initializes a new HTTP POST request with content type
* is set to multipart/form-data
*
* @param requestURL
* @throws IOException
*/
public MultipartUtilityV2(String requestURL)
throws IOException {
// creates a unique boundary based on time stamp
URL url = new URL(requestURL);
httpConn = (HttpURLConnection) url.openConnection();
httpConn.setUseCaches(false);
httpConn.setDoOutput(true); // indicates POST method
httpConn.setDoInput(true);
httpConn.setRequestMethod("POST");
httpConn.setRequestProperty("Connection", "Keep-Alive");
httpConn.setRequestProperty("Cache-Control", "no-cache");
httpConn.setRequestProperty(
"Content-Type", "multipart/form-data;boundary=" + this.boundary);
request = new DataOutputStream(httpConn.getOutputStream());
}
/**
* Adds a form field to the request
*
* @param name field name
* @param value field value
*/
public void addFormField(String name, String value)throws IOException {
request.writeBytes(this.twoHyphens + this.boundary + this.crlf);
request.writeBytes("Content-Disposition: form-data; name=\"" + name + "\""+ this.crlf);
request.writeBytes("Content-Type: text/plain; charset=UTF-8" + this.crlf);
request.writeBytes(this.crlf);
request.writeBytes(value+ this.crlf);
request.flush();
}
/**
* Adds a upload file section to the request
*
* @param fieldName name attribute in <input type="file" name="..." />
* @param uploadFile a File to be uploaded
* @throws IOException
*/
public void addFilePart(String fieldName, File uploadFile)
throws IOException {
String fileName = uploadFile.getName();
request.writeBytes(this.twoHyphens + this.boundary + this.crlf);
request.writeBytes("Content-Disposition: form-data; name=\"" +
fieldName + "\";filename=\"" +
fileName + "\"" + this.crlf);
request.writeBytes(this.crlf);
byte[] bytes = Files.readAllBytes(uploadFile.toPath());
request.write(bytes);
}
/**
* Completes the request and receives response from the server.
*
* @return a list of Strings as response in case the server returned
* status OK, otherwise an exception is thrown.
* @throws IOException
*/
public String finish() throws IOException {
String response ="";
request.writeBytes(this.crlf);
request.writeBytes(this.twoHyphens + this.boundary +
this.twoHyphens + this.crlf);
request.flush();
request.close();
// checks server's status code first
int status = httpConn.getResponseCode();
if (status == HttpURLConnection.HTTP_OK) {
InputStream responseStream = new
BufferedInputStream(httpConn.getInputStream());
BufferedReader responseStreamReader =
new BufferedReader(new InputStreamReader(responseStream));
String line = "";
StringBuilder stringBuilder = new StringBuilder();
while ((line = responseStreamReader.readLine()) != null) {
stringBuilder.append(line).append("\n");
}
responseStreamReader.close();
response = stringBuilder.toString();
httpConn.disconnect();
} else {
throw new IOException("Server returned non-OK status: " + status);
}
return response;
}
}
答案 4 :(得分：2)
基于Mihai的解决方案，如果有人在服务器上保存图像的问题，就像在我的服务器上发生的那样。将位图更改为bytebuffer部分：
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG,100,bos);
byte[] pixels = bos.toByteArray();
答案 5 :(得分：1)
我没有对此进行测试，但您可以尝试使用PipedInputStream和PipedOutputStream。它可能看起来像：
final Bitmap bmp = … // your bitmap
// Set up Piped streams
final PipedOutputStream pos = new PipedOutputStream(new ByteArrayOutputStream());
final PipedInputStream pis = new PipedInputStream(pos);
// Send bitmap data to the PipedOutputStream in a separate thread
new Thread() {
public void run() {
bmp.compress(Bitmap.CompressFormat.PNG, 100, pos);
}
}.start();
// Send POST request
try {
// Construct InputStreamEntity that feeds off of the PipedInputStream
InputStreamEntity reqEntity = new InputStreamEntity(pis, -1);
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
reqEntity.setContentType("binary/octet-stream");
reqEntity.setChunked(true);
httppost.setEntity(reqEntity);
HttpResponse response = httpclient.execute(httppost);
} catch (Exception e) {
e.printStackTrace()
}
答案 6 :(得分：1)
这个答案https://stackoverflow.com/a/33149413/6481542让我有90％的时间将大文件上传到开发Django服务器，但我不得不使用setFixedLengthStreamingMode来使其工作。这需要在写入内容之前设置内容长度，因此需要对上述答案进行相当重要的重写。这是我的最终结果
public class MultipartLargeUtility {
private final String boundary;
private static final String LINE_FEED = "\r\n";
private HttpURLConnection httpConn;
private String charset;
private OutputStream outputStream;
private PrintWriter writer;
private final int maxBufferSize = 4096;
private long contentLength = 0;
private URL url;
private List<FormField> fields;
private List<FilePart> files;
private class FormField {
public String name;
public String value;
public FormField(String name, String value) {
this.name = name;
this.value = value;
}
}
private class FilePart {
public String fieldName;
public File uploadFile;
public FilePart(String fieldName, File uploadFile) {
this.fieldName = fieldName;
this.uploadFile = uploadFile;
}
}
/**
* This constructor initializes a new HTTP POST request with content type
* is set to multipart/form-data
*
* @param requestURL
* @param charset
* @throws IOException
*/
public MultipartLargeUtility(String requestURL, String charset, boolean requireCSRF)
throws IOException {
this.charset = charset;
// creates a unique boundary based on time stamp
boundary = "===" + System.currentTimeMillis() + "===";
url = new URL(requestURL);
fields = new ArrayList<>();
files = new ArrayList<>();
if (requireCSRF) {
getCSRF();
}
}
/**
* Adds a form field to the request
*
* @param name field name
* @param value field value
*/
public void addFormField(String name, String value)
throws UnsupportedEncodingException {
String fieldContent = "--" + boundary + LINE_FEED;
fieldContent += "Content-Disposition: form-data; name=\"" + name + "\"" + LINE_FEED;
fieldContent += "Content-Type: text/plain; charset=" + charset + LINE_FEED;
fieldContent += LINE_FEED;
fieldContent += value + LINE_FEED;
contentLength += fieldContent.getBytes(charset).length;
fields.add(new FormField(name, value));
}
/**
* Adds a upload file section to the request
*
* @param fieldName name attribute in <input type="file" name="..." />
* @param uploadFile a File to be uploaded
* @throws IOException
*/
public void addFilePart(String fieldName, File uploadFile)
throws IOException {
String fileName = uploadFile.getName();
String fieldContent = "--" + boundary + LINE_FEED;
fieldContent += "Content-Disposition: form-data; name=\"" + fieldName
+ "\"; filename=\"" + fileName + "\"" + LINE_FEED;
fieldContent += "Content-Type: "
+ URLConnection.guessContentTypeFromName(fileName) + LINE_FEED;
fieldContent += "Content-Transfer-Encoding: binary" + LINE_FEED;
fieldContent += LINE_FEED;
// file content would go here
fieldContent += LINE_FEED;
contentLength += fieldContent.getBytes(charset).length;
contentLength += uploadFile.length();
files.add(new FilePart(fieldName, uploadFile));
}
/**
* Adds a header field to the request.
*
* @param name - name of the header field
* @param value - value of the header field
*/
//public void addHeaderField(String name, String value) {
// writer.append(name + ": " + value).append(LINE_FEED);
// writer.flush();
//}
/**
* Completes the request and receives response from the server.
*
* @return a list of Strings as response in case the server returned
* status OK, otherwise an exception is thrown.
* @throws IOException
*/
public List<String> finish() throws IOException {
List<String> response = new ArrayList<String>();
String content = "--" + boundary + "--" + LINE_FEED;
contentLength += content.getBytes(charset).length;
if (!openConnection()) {
return response;
}
writeContent();
// checks server's status code first
int status = httpConn.getResponseCode();
if (status == HttpURLConnection.HTTP_OK) {
BufferedReader reader = new BufferedReader(new InputStreamReader(
httpConn.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
response.add(line);
}
reader.close();
httpConn.disconnect();
} else {
throw new IOException("Server returned non-OK status: " + status);
}
return response;
}
private boolean getCSRF()
throws IOException {
/// First, need to get CSRF token from server
/// Use GET request to get the token
CookieManager cookieManager = new CookieManager();
CookieHandler.setDefault(cookieManager);
HttpURLConnection conn = null;
conn = (HttpURLConnection) url.openConnection();
conn.setUseCaches(false); // Don't use a Cached Copy
conn.setRequestMethod("GET");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.getContent();
conn.disconnect();
/// parse the returned object for the CSRF token
CookieStore cookieJar = cookieManager.getCookieStore();
List<HttpCookie> cookies = cookieJar.getCookies();
String csrf = null;
for (HttpCookie cookie : cookies) {
Log.d("cookie", "" + cookie);
if (cookie.getName().equals("csrftoken")) {
csrf = cookie.getValue();
break;
}
}
if (csrf == null) {
Log.d(TAG, "Unable to get CSRF");
return false;
}
Log.d(TAG, "Received cookie: " + csrf);
addFormField("csrfmiddlewaretoken", csrf);
return true;
}
private boolean openConnection()
throws IOException {
httpConn = (HttpURLConnection) url.openConnection();
httpConn.setUseCaches(false);
httpConn.setDoOutput(true); // indicates POST method
httpConn.setDoInput(true);
//httpConn.setRequestProperty("Accept-Encoding", "identity");
httpConn.setFixedLengthStreamingMode(contentLength);
httpConn.setRequestProperty("Connection", "Keep-Alive");
httpConn.setRequestProperty("Content-Type",
"multipart/form-data; boundary=" + boundary);
outputStream = new BufferedOutputStream(httpConn.getOutputStream());
writer = new PrintWriter(new OutputStreamWriter(outputStream, charset),
true);
return true;
}
private void writeContent()
throws IOException {
for (FormField field : fields) {
writer.append("--" + boundary).append(LINE_FEED);
writer.append("Content-Disposition: form-data; name=\"" + field.name + "\"")
.append(LINE_FEED);
writer.append("Content-Type: text/plain; charset=" + charset).append(
LINE_FEED);
writer.append(LINE_FEED);
writer.append(field.value).append(LINE_FEED);
writer.flush();
}
for (FilePart filePart : files) {
String fileName = filePart.uploadFile.getName();
writer.append("--" + boundary).append(LINE_FEED);
writer.append(
"Content-Disposition: form-data; name=\"" + filePart.fieldName
+ "\"; filename=\"" + fileName + "\"")
.append(LINE_FEED);
writer.append(
"Content-Type: "
+ URLConnection.guessContentTypeFromName(fileName))
.append(LINE_FEED);
writer.append("Content-Transfer-Encoding: binary").append(LINE_FEED);
writer.append(LINE_FEED);
writer.flush();
FileInputStream inputStream = new FileInputStream(filePart.uploadFile);
int bufferSize = Math.min(inputStream.available(), maxBufferSize);
byte[] buffer = new byte[bufferSize];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer, 0, bufferSize)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.flush();
inputStream.close();
writer.append(LINE_FEED);
writer.flush();
}
writer.append("--" + boundary + "--").append(LINE_FEED);
writer.close();
}
}
用法与上面的答案大致相同，但我已经包含了Django默认使用表单的CSRF支持
boolean useCSRF = true;
MultipartLargeUtility multipart = new MultipartLargeUtility(url, "UTF-8",useCSRF);
multipart.addFormField("param1","value");
multipart.addFilePart("filefield",new File("/path/to/file"));
List<String> response = multipart.finish();
Log.w(TAG,"SERVER REPLIED:");
for(String line : response) {
Log.w(TAG, "Upload Files Response:::" + line);
}
答案 7 :(得分：0)
以下是我使用帖子请求上传照片所做的工作。
public void uploadFile(int directoryID, String filePath) {
Bitmap bitmapOrg = BitmapFactory.decodeFile(filePath);
ByteArrayOutputStream bao = new ByteArrayOutputStream();
String upload_url = BASE_URL + UPLOAD_FILE;
bitmapOrg.compress(Bitmap.CompressFormat.JPEG, 90, bao);
byte[] data = bao.toByteArray();
HttpClient httpClient = new DefaultHttpClient();
HttpPost postRequest = new HttpPost(upload_url);
MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);
try {
// Set Data and Content-type header for the image
FileBody fb = new FileBody(new File(filePath), "image/jpeg");
StringBody contentString = new StringBody(directoryID + "");
entity.addPart("file", fb);
entity.addPart("directory_id", contentString);
postRequest.setEntity(entity);
HttpResponse response = httpClient.execute(postRequest);
// Read the response
String jsonString = EntityUtils.toString(response.getEntity());
Log.e("response after uploading file ", jsonString);
} catch (Exception e) {
Log.e("Error in uploadFile", e.getMessage());
}
}
注意：此代码需要库，请按照here的说明操作以获取库。
答案 8 :(得分：0)
我发现使用okHttp要容易得多，因为我无法使用这些解决方案：https://stackoverflow.com/a/37942387/447549
答案 9 :(得分：0)
我尝试了上面的解决方案，没有一个能为我开箱即用。
然而http://www.baeldung.com/httpclient-post-http-request。第6行POST多部分请求在几秒钟内完成
public void whenSendMultipartRequestUsingHttpClient_thenCorrect()
throws ClientProtocolException, IOException {
CloseableHttpClient client = HttpClients.createDefault();
HttpPost httpPost = new HttpPost("http://www.example.com");
MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.addTextBody("username", "John");
builder.addTextBody("password", "pass");
builder.addBinaryBody("file", new File("test.txt"),
ContentType.APPLICATION_OCTET_STREAM, "file.ext");
HttpEntity multipart = builder.build();
httpPost.setEntity(multipart);
CloseableHttpResponse response = client.execute(httpPost);
client.close();
}