Mihai Todor
Dado que los desarrolladores de Android recomendar usar el HttpURLConnection clase, me preguntaba si alguien me puede proporcionar un buen ejemplo sobre cómo enviar un “archivo” de mapa de bits (en realidad, una secuencia en memoria) a través de POST a un servidor Apache HTTP. No estoy interesado en cookies o autenticación ni nada complicado, pero solo quiero tener una implementación lógica y confiable. Todos los ejemplos que he visto por aquí se parecen más a “probemos esto y tal vez funcione”.
En este momento, tengo este código:
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();
}
}
donde showDialog solo debería mostrar un AlertDialog (¿en caso de una URL no válida?).
Ahora, digamos que genero un mapa de bits así: Bitmap image = this.getBitmap() dentro de un control derivado de View y quiero enviarlo por POST. ¿Cuál sería el procedimiento adecuado para lograr tal cosa? ¿Qué clases necesito usar? Puedo usar HttpPost como en este ejemplo? Si es así, ¿cómo construiría el InputStreamEntity para mi mapa de bits? Me parecería repugnante tener que almacenar primero el mapa de bits en un archivo en el dispositivo.
También debo mencionar que realmente necesito enviar cada píxel inalterado del mapa de bits original al servidor, por lo que no puedo convertirlo a JPEG.
Mihai Todor
No tengo idea de por qué el HttpURLConnection class no proporciona ningún medio para enviar archivos sin tener que componer el contenedor del archivo manualmente. Esto es lo que terminé haciendo, pero si alguien conoce una solución mejor, hágamelo saber.
Datos de entrada:
Bitmap bitmap = myView.getBitmap();
Material estático:
String attachmentName = "bitmap";
String attachmentFileName = "bitmap.bmp";
String crlf = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
Configure la solicitud:
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);
Envoltura de contenido de inicio:
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 para 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);
Envoltura de contenido final:
request.writeBytes(this.crlf);
request.writeBytes(this.twoHyphens + this.boundary +
this.twoHyphens + this.crlf);
Limpiar el búfer de salida:
request.flush();
request.close();
Obtener una respuesta:
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();
Cerrar flujo de respuesta:
responseStream.close();
Cierra la conexión:
httpUrlConnection.disconnect();
PD: Por supuesto que tuve que envolver la solicitud en private class AsyncUploadBitmaps extends AsyncTask<Bitmap, Void, String>para hacer feliz a la plataforma Android, porque no le gusta tener solicitudes de red en el hilo principal.
De hecho, encontré una mejor manera de enviar archivos usando HttpURLConnection usando MultipartEntity
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();
}
Suponiendo que está cargando una imagen con datos de mapa de bits:
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);
¡Y voilá! Los datos de su publicación contendrán un campo de imagen junto con el nombre del archivo y la ruta en su servidor.
jaydipsinh zala
Para cargar un archivo en el servidor con algún parámetro usando MultipartUtility de manera sencilla.
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();
}
}
Para upload usted file junto con parámetros.
NOTA: coloque este código a continuación en un subproceso que no sea ui para obtener una respuesta.
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.
Georgevik
la solucion de jaydipsinh zala no funcionó para mí, no sé por qué, pero parece estar cerca de la solución.
Entonces fusionando este con la gran solución y explicación de Mihai Todor, el resultado es esta clase que actualmente funciona para mí. Si ayuda a alguien:
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;
}
}
nick c
Esta respuesta https://stackoverflow.com/a/33149413/6481542 me ayudó en un 90 % con la carga de archivos grandes en un servidor Django de desarrollo, pero tuve que usar establecerFixedLengthStreamingMode para que funcione. Eso requiere configurar Content-Length antes de escribir el contenido, lo que requiere una reescritura bastante significativa de la respuesta anterior. Aquí está mi resultado 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();
}
}
El uso es en gran medida el mismo que en la respuesta anterior, pero he incluido el soporte CSRF que Django usa de forma predeterminada con los formularios.
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);
}
Mihai Todor
basado en la solución de Mihai, si alguien tiene el problema de guardar imágenes en el servidor como sucedió en mi servidor. cambie la parte Bitmap a bytebuffer a:
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG,100,bos);
byte[] pixels = bos.toByteArray();
rico yao
No he probado esto, pero puede intentar usar PipedInputStream y PipedOutputStream. Podría verse algo como:
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()
}
Consulte esta discusión SO
– Aniket Thakur
12 de abril de 2017 a las 16:42