Question

我们正在使用Amazon AWS Java Library上传文件，但很难获得上传进度。我们现在打电话给以下人员：

File file = new File(localAsset.getVideoFilePath());
PutObjectRequest putObjectRequest = new PutObjectRequest(bucket, localAsset.getFileName(), file);
s3.putObject(putObjectRequest);

我们如何设置回调来检查文件上传进度？

由于

Answer 1

我遇到了这个确切的问题，写了一个简单的InputStream包装器，打印出好的进度条：

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;
    }

    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();
        }
        return lastUpdate;
    }
}

（这是从实时代码中复制粘贴的，因此您可能需要进行一些修复才能使其在您自己的代码中运行。）

然后，只需使用InputStream放置东西的方式（确保指定大小！），它将为您提供一个很好的进度条。如果你想要一个适当的回调，那也很容易。

Answer 2

目前还没有简单的方法可以“内置”，但您可以通过包装传入的InputStream来轻松实现一个，以报告它的读取距离。

您可以在论坛上阅读team's official response此问题。

值得注意的是，.NET SDK 确实具有此功能，但据我所知，它以类似的“hackish”方式实现（简单地说，S3 API本身没有'确实有优雅的内置条款）。如果您自己无法实施，那么可能需要寻找灵感。

Answer 3

使用进度监听器跟踪进度

File file = new File(localAsset.getVideoFilePath());
PutObjectRequest putObjectRequest = new PutObjectRequest(bucket, localAsset.getFileName(), file);

putObjectRequest.setGeneralProgressListener(new ProgressListener() {
      long transferred = 0;

      @Override
      public void progressChanged(ProgressEvent progressEvent) {
            transferred += progressEvent.getBytesTransferred();
            Timber.i("Transferred %f%%", code, ((float)transferred / (float) fileSize) * 100f);
        }
    });

s3.putObject(putObjectRequest);

使用进度回调将文件或InputStream上载到S3

3 个答案: