Question

我正在尝试从InputStream读取数据，并使用RandomAccessFile将其写入sdcard。我想实现下载速度。所以我认为，从RandomAccessFile获得写作速度是实现这一目标的最佳方式。这是我的代码：

long downloaded = 0;
status = DOWNLOADING; 
URL url = new URL(requestUrl);

try {
    String extStorage = Environment.getExternalStorageDirectory().getPath();
    String file = extStorage+"/abc.zip";

    RandomAccessFile output = new RandomAccessFile(file, "rw");

    System.setProperty("http.keepAlive", "false");

    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
    connection.setReadTimeout(5000);
    connection.setRequestMethod("GET");
    connection.connect();

    long fileLength = connection.getContentLength();
    InputStream stream = connection.getInputStream();

    while (status == DOWNLOADING) {
        byte buffer[] = new byte[1024];

        // Read from server into buffer.
        int read = stream.read(buffer);
        if (read == -1)
            break;

        // Write buffer to file. I need to get this writing speed.
        output.write(buffer, 0, read);
        downloaded += read;
    }
    output.close();
    stream.close();
}

如何从RandomAccessFile以KB /秒为单位获得写入速度？

或者，您有什么想法吗？

感谢您的帮助。

Answer 1

你可以从一个类似于此的东西中得到一个粗略的东西：开始每隔一秒调用一次runnable。在课堂上有

private static int bytesWritten = 0;
private static int kbPerSec = 0;

runnable内部有类似

的内容

kbPerSec = bytesWritten / 1000;
bytesWritten = 0;
//Do with the result what you want

稍微修改你的while循环

kbPerSec = 0;
bytesWritten = 0;
//Start runnable
while (status == DOWNLOADING) {
    byte buffer[] = new byte[1024];

    // Read from server into buffer.
    int read = stream.read(buffer);
    if (read == -1)
        break;

    // Write buffer to file. I need to get this writing speed.
    output.write(buffer, 0, read);
    //Keep track of how much has been written since the last time the runnable was called
    bytesWritten += read;
    downloaded += read;
}
//Stop runnable

如何以KB /秒的速度获得下载速度？

1 个答案: