android - 使用 OKHTTP 跟踪分段文件上传的进度

Question

我正在尝试实现一个进度条来指示分段文件上传的进度。

我已阅读对此答案的评论 - https://stackoverflow.com/a/24285633/1022454我必须包装传递给 RequestBody 的接收器并提供一个回调来跟踪移动的字节。

我创建了一个自定义 RequestBody 并用 CustomSink 类包装了接收器，但是通过调试我可以看到字节正在由 RealBufferedSink 写入ln 44 并且自定义接收器写入方法只运行一次，不允许我跟踪移动的字节。

    private class CustomRequestBody extends RequestBody {

    MediaType contentType;
    byte[] content;

    private CustomRequestBody(final MediaType contentType, final byte[] content) {
        this.contentType = contentType;
        this.content = content;
    }

    @Override
    public MediaType contentType() {
        return contentType;
    }

    @Override
    public long contentLength() {
        return content.length;
    }

    @Override
    public void writeTo(BufferedSink sink) throws IOException {
        CustomSink customSink = new CustomSink(sink);
        customSink.write(content);

    }
}


private class CustomSink implements BufferedSink {

    private static final String TAG = "CUSTOM_SINK";

    BufferedSink bufferedSink;

    private CustomSink(BufferedSink bufferedSink) {
        this.bufferedSink = bufferedSink;
    }

    @Override
    public void write(Buffer source, long byteCount) throws IOException {
        Log.d(TAG, "source size: " + source.size() + " bytecount" + byteCount);
        bufferedSink.write(source, byteCount);
    }

    @Override
    public void flush() throws IOException {
        bufferedSink.flush();
    }

    @Override
    public Timeout timeout() {
        return bufferedSink.timeout();
    }

    @Override
    public void close() throws IOException {
        bufferedSink.close();
    }

    @Override
    public Buffer buffer() {
        return bufferedSink.buffer();
    }

    @Override
    public BufferedSink write(ByteString byteString) throws IOException {
        return bufferedSink.write(byteString);
    }

    @Override
    public BufferedSink write(byte[] source) throws IOException {
        return bufferedSink.write(source);
    }

    @Override
    public BufferedSink write(byte[] source, int offset, int byteCount) throws IOException {
        return bufferedSink.write(source, offset, byteCount);
    }

    @Override
    public long writeAll(Source source) throws IOException {
        return bufferedSink.writeAll(source);
    }

    @Override
    public BufferedSink writeUtf8(String string) throws IOException {
        return bufferedSink.writeUtf8(string);
    }

    @Override
    public BufferedSink writeString(String string, Charset charset) throws IOException {
        return bufferedSink.writeString(string, charset);
    }

    @Override
    public BufferedSink writeByte(int b) throws IOException {
        return bufferedSink.writeByte(b);
    }

    @Override
    public BufferedSink writeShort(int s) throws IOException {
        return bufferedSink.writeShort(s);
    }

    @Override
    public BufferedSink writeShortLe(int s) throws IOException {
        return bufferedSink.writeShortLe(s);
    }

    @Override
    public BufferedSink writeInt(int i) throws IOException {
        return bufferedSink.writeInt(i);
    }

    @Override
    public BufferedSink writeIntLe(int i) throws IOException {
        return bufferedSink.writeIntLe(i);
    }

    @Override
    public BufferedSink writeLong(long v) throws IOException {
        return bufferedSink.writeLong(v);
    }

    @Override
    public BufferedSink writeLongLe(long v) throws IOException {
        return bufferedSink.writeLongLe(v);
    }

    @Override
    public BufferedSink emitCompleteSegments() throws IOException {
        return bufferedSink.emitCompleteSegments();
    }

    @Override
    public OutputStream outputStream() {
        return bufferedSink.outputStream();
    }
}

有没有人举个例子说明我会怎么做？

Answer 1

您必须创建一个自定义 RequestBody 并覆盖 writeTo 方法，并且您必须将文件分段发送到接收器。在每个段之后刷新接收器是非常重要的，否则你的进度条将很快填满，而文件实际上并没有通过网络发送，因为内容将留在接收器中(它就像一个缓冲区)。

public class CountingFileRequestBody extends RequestBody {

    private static final int SEGMENT_SIZE = 2048; // okio.Segment.SIZE

    private final File file;
    private final ProgressListener listener;
    private final String contentType;

    public CountingFileRequestBody(File file, String contentType, ProgressListener listener) {
        this.file = file;
        this.contentType = contentType;
        this.listener = listener;
    }

    @Override
    public long contentLength() {
        return file.length();
    }

    @Override
    public MediaType contentType() {
        return MediaType.parse(contentType);
    }

    @Override
    public void writeTo(BufferedSink sink) throws IOException {
        Source source = null;
        try {
            source = Okio.source(file);
            long total = 0;
            long read;

            while ((read = source.read(sink.buffer(), SEGMENT_SIZE)) != -1) {
                total += read;
                sink.flush();
                this.listener.transferred(total);

            }
        } finally {
            Util.closeQuietly(source);
        }
    }

    public interface ProgressListener {
        void transferred(long num);
    }

}

您可以在我的 gist 中找到一个支持在 AdapterView 中显示进度并取消上传的完整实现:​​https://gist.github.com/eduardb/dd2dc530afd37108e1ac