我正在使用 Java 将多个文件上传到 Amazon S3。
我正在使用的代码如下：
MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
MultiValueMap < String,
MultipartFile > map = multipartRequest.getMultiFileMap();
try {
if (map != null) {
for (String filename: map.keySet()) {
List < MultipartFile > fileList = map.get(filename);
incrPercentge = 100 / fileList.size();
request.getSession().setAttribute("incrPercentge", incrPercentge);
for (MultipartFile mpf: fileList) {
/*
* custom input stream wrap to original input stream to get
* the progress
*/
ProgressInputStream inputStream = new ProgressInputStream("test", mpf.getInputStream(), mpf.getBytes().length);
ObjectMetadata metadata = new ObjectMetadata();
metadata.setContentType(mpf.getContentType());
String key = Util.getLoginUserName() + "/" + mpf.getOriginalFilename();
PutObjectRequest putObjectRequest = new PutObjectRequest(
Constants.S3_BUCKET_NAME, key, inputStream, metadata).withStorageClass(StorageClass.ReducedRedundancy);
PutObjectResult response = s3Client.putObject(putObjectRequest);
}
}
}
} catch(Exception e) {
e.printStackTrace();
}
我必须创建自定义输入流以获取 Amazon S3 使用的数字字节。我从这里的问题中得到了这个想法：Upload file or InputStream to S3 with a progress callback
我的ProgressInputStream课程代码如下：
package com.spectralnetworks.net.util;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.vfs.FileContent;
import org.apache.commons.vfs.FileSystemException;
public class ProgressInputStream extends InputStream {
private final long size;
private long progress,
lastUpdate = 0;
private final InputStream inputStream;
private final String name;
private boolean closed = false;
public ProgressInputStream(String name, InputStream inputStream, long size) {
this.size = size;
this.inputStream = inputStream;
this.name = name;
}
public ProgressInputStream(String name, FileContent content)
throws FileSystemException {
this.size = content.getSize();
this.name = name;
this.inputStream = content.getInputStream();
}
@Override
public void close() throws IOException {
super.close();
if (closed) throw new IOException("already closed");
closed = true;
}
@Override
public int read() throws IOException {
int count = inputStream.read();
if (count > 0) progress += count;
lastUpdate = maybeUpdateDisplay(name, progress, lastUpdate, size);
return count;
}@Override
public int read(byte[] b, int off, int len) throws IOException {
int count = inputStream.read(b, off, len);
if (count > 0) progress += count;
lastUpdate = maybeUpdateDisplay(name, progress, lastUpdate, size);
return count;
}
/**
* This is on reserach to show a progress bar
* @param name
* @param progress
* @param lastUpdate
* @param size
* @return
*/
static long maybeUpdateDisplay(String name, long progress, long lastUpdate, long size) {
/* if (Config.isInUnitTests()) return lastUpdate;
if (size < B_IN_MB/10) return lastUpdate;
if (progress - lastUpdate > 1024 * 10) {
lastUpdate = progress;
int hashes = (int) (((double)progress / (double)size) * 40);
if (hashes > 40) hashes = 40;
String bar = StringUtils.repeat("#",
hashes);
bar = StringUtils.rightPad(bar, 40);
System.out.format("%s [%s] %.2fMB/%.2fMB\r",
name, bar, progress / B_IN_MB, size / B_IN_MB);
System.out.flush();
}*/
System.out.println("name " + name + " progress " + progress + " lastUpdate " + lastUpdate + " " + "sie " + size);
return lastUpdate;
}
}
但这不能正常工作。它立即打印到文件大小，如下所示：
name test progress 4096 lastUpdate 0 sie 30489
name test progress 8192 lastUpdate 0 sie 30489
name test progress 12288 lastUpdate 0 sie 30489
name test progress 16384 lastUpdate 0 sie 30489
name test progress 20480 lastUpdate 0 sie 30489
name test progress 24576 lastUpdate 0 sie 30489
name test progress 28672 lastUpdate 0 sie 30489
name test progress 30489 lastUpdate 0 sie 30489
name test progress 30489 lastUpdate 0 sie 30489
并且实际上传需要更多时间（打印行后超过 10 次）。
我应该怎么做才能获得真正的上传状态？