我几乎不知道html是如何工作的。我想要做的是与以下完全相似但在Android上
<body>
<form action="<%= some_url %>" method="post" enctype="multipart/form-data">
<input type="file" name="myFile">
<input type="submit" value="Submit">
</form>
</body>
我尝试了以下代码 -
private static void postToUrl(String url_to_upload_on,
String file_name_with_ext, byte[] byteArray) {
String attachmentName = "file";
String attachmentFileName = file_name_with_ext;
String crlf = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
try{
URL url = new URL(url_to_upload_on);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.setRequestProperty(
"Content-Type", "multipart/form-data;boundary=" + boundary);
DataOutputStream request = new DataOutputStream(
connection.getOutputStream());
request.writeBytes(twoHyphens + boundary + crlf);
request.writeBytes("Content-Disposition: form-data; name=\"" +
attachmentName + "\";filename=\"" +
attachmentFileName + "\"" + crlf);
request.writeBytes(crlf);
request.write(byteArray);
request.writeBytes(crlf);
request.writeBytes(twoHyphens + boundary +
twoHyphens + crlf);
request.flush();
request.close();
}catch(Exception e){
e.printStackTrace();
}
}
这给了我没有直接错误但是当我使用 -
获得错误流时 Log.w(TAG, "connection.getErrorStream() = " + connection.getErrorStream());
我明白了 -
12-14 18:25:54.911: W/uploadToBlobStore(30558): httpUrlConnection.getErrorStream() = com.android.okhttp.internal.http.HttpTransport$FixedLengthInputStream@426dd5a8
没有成功。
PS-我正在将文件上传到google blobstore
PS-我不能使用Apache http库或其多部分类，因为android说其折旧
编辑1
现在我使用以下代码，但它仅适用于低于2.3Mb的文件 -
private static void postToUrl3(String url_to_upload_on,
String file_name_with_ext, byte[] byteArray, String mimeType) {
CloseableHttpClient httpClient = null;
try {
httpClient = HttpClientBuilder.create().build();
HttpPost postRequest = new HttpPost(url_to_upload_on);
MultipartEntityBuilder reqEntity = MultipartEntityBuilder.create();
reqEntity.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
ByteArrayBody bab = new ByteArrayBody(byteArray, file_name_with_ext);
reqEntity.addPart("file", bab);
postRequest.setEntity(reqEntity.build());
httpClient.execute(postRequest);// takes time
} catch (Exception e) {
Log.w("uploadToBlobStore", "postToUrl Exception e = " + e);
e.printStackTrace();
} finally {
if (httpClient != null) {
Log.w("uploadToBlobStore", "connection.closing ");
try {
httpClient.close();
} catch (IOException e) {
Log.w("uploadToBlobStore", "connection.closing errot e = "
+ e);
e.printStackTrace();
}
}
}
}
如何使其适用于更大的文件？
PS - 我将它发送到blobstore，我确实将maxUploadSizeBytes和MaxUploadSizeBytesPerBlob设置为30MB。我无法弄清楚尺寸问题，因为谷歌blobstore文档说 -
Google App Engine包含Blobstore服务，该服务允许应用程序提供仅受可通过单个HTTP连接上载或下载的数据量限制的数据对象。
http连接也有问题吗？如果是的话，我该如何配置呢。
答案 0 :(得分：67)
我正在使用HttpURLConnection来实现这一目标。
创建一个Multipart自定义类::
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);
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);
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 List<String> finish() throws IOException {
List<String> response = new ArrayList<String>();
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.add(line);
}
reader.close();
httpConn.disconnect();
} else {
throw new IOException("Server returned non-OK status: " + status);
}
return response;
}
}
使用它（异步方式）::
MultipartUtility multipart = new MultipartUtility(requestURL, charset);
// In your case you are not adding form data so ignore this
/*This is to add parameter values */
for (int i = 0; i < myFormDataArray.size(); i++) {
multipart.addFormField(myFormDataArray.get(i).getParamName(),
myFormDataArray.get(i).getParamValue());
}
//add your file here.
/*This is to add file content*/
for (int i = 0; i < myFileArray.size(); i++) {
multipart.addFilePart(myFileArray.getParamName(),
new File(myFileArray.getFileName()));
}
List<String> response = multipart.finish();
Debug.e(TAG, "SERVER REPLIED:");
for (String line : response) {
Debug.e(TAG, "Upload Files Response:::" + line);
// get your server response here.
responseString = line;
}
答案 1 :(得分：9)
根据服务器的期望调整标头值。
private static final String IMGUR_CLIENT_ID = "...";
private static final MediaType MEDIA_TYPE_PNG = MediaType.parse("image/png");
private final OkHttpClient client = new OkHttpClient();
public void run() throws Exception {
// Use the imgur image upload API as documented at https://api.imgur.com/endpoints/image
RequestBody requestBody = new MultipartBuilder()
.type(MultipartBuilder.FORM)
.addPart(
Headers.of("Content-Disposition", "form-data; name=\"title\""),
RequestBody.create(null, "Square Logo"))
.addPart(
Headers.of("Content-Disposition", "form-data; name=\"image\""),
RequestBody.create(MEDIA_TYPE_PNG, new File("website/static/logo-square.png")))
.build();
Request request = new Request.Builder()
.header("Authorization", "Client-ID " + IMGUR_CLIENT_ID)
.url("https://api.imgur.com/3/image")
.post(requestBody)
.build();
Response response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
System.out.println(response.body().string());
}
答案 2 :(得分：6)
作为替代方案，您可以使用 Retrofit 。
你可以像这样指定一个电话：
@Multipart
@POST("/user/photo")
Call<User> updateUser(@Part("photo") RequestBody photo, @Part("description") RequestBody description);
然后像这样创建它：
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://api.github.com")
.build();
GitHubService service = retrofit.create(GitHubService.class);
最后像这样执行：
service.updateUser(Photo, description).enqueue() - ＆gt;的异步
service.updateUser(Photo, description).execute() - ＆gt;的同步
请参阅文档here
答案 3 :(得分：0)
Volley是一个用于多部分数据的好的http库。
AndroidMultiPartEntity类用于进度监听器。
public class AndroidMultiPartEntity extends MultipartEntity
{
private final ProgressListener listener;
public AndroidMultiPartEntity(final ProgressListener listener) {
super();
this.listener = listener;
}
public AndroidMultiPartEntity(final HttpMultipartMode mode, final ProgressListener listener) {
super(mode);
this.listener = listener;
}
public AndroidMultiPartEntity(HttpMultipartMode mode, final String boundary,
final Charset charset, final ProgressListener listener) {
super(mode, boundary, charset);
this.listener = listener;
}
@Override
public void writeTo(final OutputStream outstream) throws IOException {
super.writeTo(new CountingOutputStream(outstream, this.listener));
}
public static interface ProgressListener {
void transferred(long num);
}
public static class CountingOutputStream extends FilterOutputStream {
private final ProgressListener listener;
private long transferred;
public CountingOutputStream(final OutputStream out,
final ProgressListener listener) {
super(out);
this.listener = listener;
this.transferred = 0;
}
public void write(byte[] b, int off, int len) throws IOException {
out.write(b, off, len);
this.transferred += len;
this.listener.transferred(this.transferred);
}
public void write(int b) throws IOException {
out.write(b);
this.transferred++;
this.listener.transferred(this.transferred);
}
}
}
Call the Async task like this
new UploadFileToServer().execute();
The Call method:
private class UploadFileToServer extends AsyncTask<Void, Integer, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected void onProgressUpdate(Integer... progress) {
}
@Override
protected String doInBackground(Void... params) {
return uploadFile();
}
private String uploadFile() {
String responseString = null;
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(Config.Seeker_Image_Upload);
try {
AndroidMultiPartEntity entity = new AndroidMultiPartEntity(new AndroidMultiPartEntity.ProgressListener() {
@Override
public void transferred(long num) {
publishProgress((int) ((num / (float) totalSize) * 100));
}
});
File sourceFile = new File(Path);
// Adding file data to http body
entity.addPart("logo", new FileBody(sourceFile));
// Extra parameters if you want to pass to server
//entity.addPart("website", new StringBody("www.androidhive.info"));
// String emailaddress = UserActivity.emailaddress;
/*preferences = SeekerProfile.this.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
email_address = preferences.getString("EMAILADDRESS", "");*/
entity.addPart("EMAILADDRESS", new StringBody(email_address));
entity.addPart("OPER", new StringBody(Operation_recruiter_logo_upload));
totalSize = entity.getContentLength();
httppost.setEntity(entity);
// Making server call
HttpResponse response = httpclient.execute(httppost);
HttpEntity r_entity = response.getEntity();
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode == 200) {
// Server response
responseString = EntityUtils.toString(r_entity);
} else {
responseString = "Error occurred! Http Status Code: " + statusCode;
}
} catch (ClientProtocolException e) {
responseString = e.toString();
} catch (IOException e) {
responseString = e.toString();
}
return responseString;
}
@Override
protected void onPostExecute(String result) {
//Log.e(TAG, "Response from server: " + result);
enter code here
}
}