我正在尝试修改cloudinary的开源库,以便我可以收听上传照片的进度.库类包含一个MultipartUtility
java类,我修改它以监听上载的进度.
修改前的原始代码可以在github：https://github.com/cloudinary/cloudinary_java/blob/master/cloudinary-android/src/main/java/com/cloudinary/android/MultipartUtility.java上找到
我将其修改为类似于另一个云服务CloudFS的代码,该代码在上传文件/图像等时支持进度：
package com.cloudinary.android;
import com.cloudinary.Cloudinary;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Map;
/**
* This utility class provides an abstraction layer for sending multipart HTTP
* POST requests to a web server.
*
* @author www.codejava.net
* @author Cloudinary
*/
public class MultipartUtility {
private final String boundary;
private static final String LINE_Feed = "\r\n";
private static final String APPLICATION_OCTET_STREAM = "application/octet-stream";
private HttpURLConnection httpConn;
private String charset;
private OutputStream outputStream;
private PrintWriter writer;
UploadingCallback uploadingCallback;
public final static String USER_AGENT = "CloudinaryAndroid/" + Cloudinary.VERSION;
Long filesize;
public void setUploadingCallback(UploadingCallback uploadingCallback) {
this.uploadingCallback = uploadingCallback;
}
/**
* 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,String boundary,Map<String,String> headers,Long filesize) throws IOException {
this.charset = charset;
this.boundary = boundary;
this.filesize = filesize;
URL url = new URL(requestURL);
httpConn = (HttpURLConnection) url.openConnection();
httpConn.setDoOutput(true); // indicates POST method
httpConn.setDoInput(true);
httpConn.setFixedLengthStreamingMode(filesize); //added this in
if (headers != null) {
for (Map.Entry<String,String> header : headers.entrySet()) {
httpConn.setRequestProperty(header.getKey(),header.getValue());
}
}
httpConn.setRequestProperty("Content-Type","multipart/form-data; boundary=" + boundary);
httpConn.setRequestProperty("User-Agent",USER_AGENT);
outputStream = httpConn.getOutputStream();
writer = new PrintWriter(new OutputStreamWriter(outputStream,charset),true);
}
public MultipartUtility(String requestURL,String boundary) throws IOException {
this(requestURL,charset,boundary,null,0L);
}
/**
* 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 {@code <input type="file" name="..." />}
* @param uploadFile a File to be uploaded
* @throws IOException
*/
public void addFilePart(String fieldName,File uploadFile,String fileName) throws IOException {
if (fileName == null) fileName = uploadFile.getName();
FileInputStream inputStream = new FileInputStream(uploadFile);
addFilePart(fieldName,inputStream,fileName);
}
public void addFilePart(String fieldName,File uploadFile) throws IOException {
addFilePart(fieldName,uploadFile,"file");
}
public void addFilePart(String fieldName,InputStream inputStream,String fileName) throws IOException {
if (fileName == null) fileName = "file";
writer.append("--" + boundary).append(LINE_Feed);
writer.append("Content-Disposition: form-data; name=\"" + fieldName + "\"; filename=\"" + fileName + "\"").append(LINE_Feed);
writer.append("Content-Type: ").append(APPLICATION_OCTET_STREAM).append(LINE_Feed);
writer.append("Content-Transfer-Encoding: binary").append(LINE_Feed);
writer.append(LINE_Feed);
writer.flush();
int progress = 0;
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer,bytesRead);
progress += bytesRead;
/* int percentage = ((progress / filesize.intValue()) * 100);*/
if (uploadingCallback != null) {
uploadingCallback.uploadListener(progress);
}
}
outputStream.flush();
writer.flush();
uploadingCallback = null;
inputStream.close();
writer.append(LINE_Feed);
writer.flush();
}
public void addFilePart(String fieldName,InputStream inputStream) throws IOException {
addFilePart(fieldName,"file");
}
/**
* 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 HttpURLConnection execute() throws IOException {
writer.append("--" + boundary + "--").append(LINE_Feed);
writer.close();
return httpConn;
}
}
我所做的更改是按照此线程的建议将以下内容添加到httpURLConnection：How to implement file upload progress bar in android：httpConn.setFixedLengthStreamingMode(filesize);
然后我创建了一个简单的界面来监听上传进度：
public interface UploadingCallback {
void uploadListener(int progress);
}
然后我在HttpURLConnection写下照片时附上它：
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer,bytesRead);
progress += bytesRead;
/* int percentage = ((progress / filesize.intValue()) * 100);*/
if (uploadingCallback != null) {
uploadingCallback.uploadListener(progress);
}
}
代码已运行,但上传的进度似乎没有正确测量.这张照片大概是365kb,上传时间大约是十分之一秒(我开始上传时间为17：56：55.481,17：56：55.554已完成上传,这只是超过0.7秒).我不相信我的互联网连接速度很快,并且预计它至少需要5秒钟.我感觉它正在测量将照片写入缓冲区所花费的时间,而不是将它发送到cloudinary服务器所花费的时间.
我怎样才能测量上传照片所需的时间,以便我可以将数据用于进度条？
04-24 17:56:55.481 28306-28725/com.a upload 4096 04-24 17:56:55.486 28306-28725/com.a upload 8192 04-24 17:56:55.486 28306-28725/com.a upload 12288 04-24 17:56:55.486 28306-28725/com.a upload 16384 04-24 17:56:55.487 28306-28725/com.a upload 20480 04-24 17:56:55.487 28306-28725/com.a upload 24576 04-24 17:56:55.487 28306-28725/com.a upload 28672 04-24 17:56:55.487 28306-28725/com.a upload 32768 04-24 17:56:55.491 28306-28725/com.a upload 36864 04-24 17:56:55.492 28306-28725/com.a upload 40960 04-24 17:56:55.493 28306-28725/com.a upload 45056 04-24 17:56:55.493 28306-28725/com.a upload 49152 04-24 17:56:55.493 28306-28725/com.a upload 53248 04-24 17:56:55.493 28306-28725/com.a upload 57344 04-24 17:56:55.494 28306-28725/com.a upload 61440 04-24 17:56:55.494 28306-28725/com.a upload 65536 04-24 17:56:55.494 28306-28725/com.a upload 69632 04-24 17:56:55.494 28306-28725/com.a upload 73728 04-24 17:56:55.494 28306-28725/com.a upload 77824 04-24 17:56:55.495 28306-28725/com.a upload 81920 04-24 17:56:55.495 28306-28725/com.a upload 86016 04-24 17:56:55.495 28306-28725/com.a upload 90112 04-24 17:56:55.495 28306-28725/com.a upload 94208 04-24 17:56:55.495 28306-28725/com.a upload 98304 04-24 17:56:55.495 28306-28725/com.a upload 102400 04-24 17:56:55.495 28306-28725/com.a upload 106496 04-24 17:56:55.496 28306-28725/com.a upload 110592 04-24 17:56:55.496 28306-28725/com.a upload 114688 04-24 17:56:55.496 28306-28725/com.a upload 118784 04-24 17:56:55.497 28306-28725/com.a upload 122880 04-24 17:56:55.498 28306-28725/com.a upload 126976 04-24 17:56:55.498 28306-28725/com.a upload 131072 04-24 17:56:55.498 28306-28725/com.a upload 135168 04-24 17:56:55.498 28306-28725/com.a upload 139264 04-24 17:56:55.499 28306-28725/com.a upload 143360 04-24 17:56:55.506 28306-28725/com.a upload 147456 04-24 17:56:55.510 28306-28725/com.a upload 151552 04-24 17:56:55.510 28306-28725/com.a upload 155648 04-24 17:56:55.514 28306-28725/com.a upload 159744 04-24 17:56:55.515 28306-28725/com.a upload 163840 04-24 17:56:55.517 28306-28725/com.a upload 167936 04-24 17:56:55.517 28306-28725/com.a upload 172032 04-24 17:56:55.518 28306-28725/com.a upload 176128 04-24 17:56:55.518 28306-28725/com.a upload 180224 04-24 17:56:55.518 28306-28725/com.a upload 184320 04-24 17:56:55.519 28306-28725/com.a upload 188416 04-24 17:56:55.519 28306-28725/com.a upload 192512 04-24 17:56:55.519 28306-28725/com.a upload 196608 04-24 17:56:55.519 28306-28725/com.a upload 200704 04-24 17:56:55.520 28306-28725/com.a upload 204800 04-24 17:56:55.525 28306-28725/com.a upload 208896 04-24 17:56:55.526 28306-28725/com.a upload 212992 04-24 17:56:55.527 28306-28725/com.a upload 217088 04-24 17:56:55.530 28306-28725/com.a upload 221184 04-24 17:56:55.530 28306-28725/com.a upload 225280 04-24 17:56:55.530 28306-28725/com.a upload 229376 04-24 17:56:55.530 28306-28725/com.a upload 233472 04-24 17:56:55.530 28306-28725/com.a upload 237568 04-24 17:56:55.531 28306-28725/com.a upload 241664 04-24 17:56:55.532 28306-28725/com.a upload 245760 04-24 17:56:55.532 28306-28725/com.a upload 249856 04-24 17:56:55.532 28306-28725/com.a upload 253952 04-24 17:56:55.533 28306-28725/com.a upload 258048 04-24 17:56:55.533 28306-28725/com.a upload 262144 04-24 17:56:55.535 28306-28725/com.a upload 266240 04-24 17:56:55.540 28306-28725/com.a upload 270336 04-24 17:56:55.540 28306-28725/com.a upload 274432 04-24 17:56:55.541 28306-28725/com.a upload 278528 04-24 17:56:55.541 28306-28725/com.a upload 282624 04-24 17:56:55.543 28306-28725/com.a upload 286720 04-24 17:56:55.545 28306-28725/com.a upload 290816 04-24 17:56:55.545 28306-28725/com.a upload 294912 04-24 17:56:55.547 28306-28725/com.a upload 299008 04-24 17:56:55.547 28306-28725/com.a upload 303104 04-24 17:56:55.547 28306-28725/com.a upload 307200 04-24 17:56:55.547 28306-28725/com.a upload 311296 04-24 17:56:55.547 28306-28725/com.a upload 315392 04-24 17:56:55.548 28306-28725/com.a upload 319488 04-24 17:56:55.548 28306-28725/com.a upload 323584 04-24 17:56:55.548 28306-28725/com.a upload 327680 04-24 17:56:55.548 28306-28725/com.a upload 331776 04-24 17:56:55.549 28306-28725/com.a upload 335872 04-24 17:56:55.549 28306-28725/com.a upload 339968 04-24 17:56:55.549 28306-28725/com.a upload 344064 04-24 17:56:55.550 28306-28725/com.a upload 348160 04-24 17:56:55.550 28306-28725/com.a upload 352256 04-24 17:56:55.551 28306-28725/com.a upload 356352 04-24 17:56:55.551 28306-28725/com.a upload 360448 04-24 17:56:55.552 28306-28725/com.a upload 364544 04-24 17:56:55.554 28306-28725/com.a upload 365790
要自己测试一下,您需要在cloudinary网站上创建一个免费帐户以获取您的云端名称,这样您就可以将Android SDK连接到他们的服务,从而直接从Android直接上传到他们的服务器.
编辑：
这是我尝试过的,当上传实际在7秒内完成时,它仍然会在0.7秒内从0 – 100％跳跃：
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer,bytesRead);
progress += bytesRead;
Log.d("MultiPart","file transferred so far: "
+ progress);
if (uploadingCallback != null) {
uploadingCallback.uploadListener(progress);
}
Log.d("Flushing","flush the writer");
outputStream.flush();
writer.flush();
}
解决方法
使用flush()方法和调用update callback()的时间有问题.
每次读取部分图片时都可以从代码中看到,将其写入输出缓冲区,但这并不意味着它被发送到服务器,它可能被缓冲,然后写入服务器.
你有两个选择,在每个outputStream.write()之后调用outputStream.flush(),但这会杀死上传的性能,因为你会失去缓冲的好处.
或者,您可以在方法结束时的outputStream.flush()之后调用updateCallback().因为在outputStream.flush()之后,您确定数据在服务器上,并且该进度已结束.
有关flush的更多信息,请参阅此主题What is the purpose of flush() in Java streams?
