L'envoi de fichiers à l'aide de POST avec HttpURLConnection

Je n'ai aucune idée pourquoi le HttpURLConnection classe ne fournit aucun moyen pour envoyer des fichiers sans avoir à composer le dossier manuellement. Voici ce que j'ai fait, mais si quelqu'un connait une meilleure solution, s'il vous plaît laissez-moi savoir.

Des données d'entrée:

Bitmap bitmap = myView.getBitmap();

Statique trucs:

String attachmentName = "bitmap";
String attachmentFileName = "bitmap.bmp";
String crlf = "\r\n";
String twoHyphens = "--";
String boundary =  "*****";

Installation de la demande:

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);

Commencer contenu wrapper:

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);

Convertir Bitmap à 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);

De contenu wrapper:

request.writeBytes(this.crlf);
request.writeBytes(this.twoHyphens + this.boundary + 
    this.twoHyphens + this.crlf);

Rincer la mémoire tampon de sortie:

request.flush();
request.close();

Obtenir réponse:

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();

Fermer le flux de réponse:

responseStream.close();

Fermer la connexion:

httpUrlConnection.disconnect();

PS: bien sûr, j'avais pour envelopper la demande en private class AsyncUploadBitmaps extends AsyncTask<Bitmap, Void, String>, afin de rendre la plate-forme Android heureux, parce qu'il n'aime pas avoir des demandes de réseau sur le thread principal.

Pour télécharger le fichier sur le serveur avec un certain nombre de paramètres à l'aide de MultipartUtility de façon simple.

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();
}
}

À upload vous file avec les paramètres.

REMARQUE : placez-y le code ci-dessous dans la non-ui-thread pour obtenir de réponse.

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.

basé sur Mihai la solution, si quelqu'un a le problème de l'enregistrement des images sur le serveur, comme ce qui s'est passé sur mon serveur. modifier l'image Bitmap à bytebuffer partie :

ByteArrayOutputStream bos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG,100,bos);
byte[] pixels = bos.toByteArray();

Cette réponse https://stackoverflow.com/a/33149413/6481542 m'a fait 90% du chemin avec le téléchargement de fichiers volumineux pour un développement Django serveur, mais j'ai dû utiliser setFixedLengthStreamingMode à faire, il a travaillé. Qui nécessite le réglage de la Longueur du Contenu avant d'écrire le contenu, ce qui nécessite une assez bonne réécriture de la réponse ci-dessus. Voici mon résultat final

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();
}
}

Utilisation est essentiellement le même que dans la réponse ci-dessus, mais j'ai inclus CSRF soutien que Django utilise par défaut avec les formes

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);
}

J'ai trouvé à l'aide de okHttp beaucoup plus facile que je ne pouvais pas obtenir l'une de ces solutions de travail: https://stackoverflow.com/a/37942387/447549