Question

我编写了一个程序来上传和下载文件到FTP服务器，但我无法监控速度和传输速率我使用了FTPClient类及其两种方法retrievFile()和storeFile()

Answer 1

尝试一下：

public class ReportingOutputStream extends OutputStream {
    public static final String BYTES_PROP = "Bytes";
    private FileOutputStream fileStream;
    private long byteCount = 0L;
    private long lastByteCount = 0L;
    private long updateInterval = 1L << 10;
    private long nextReport = updateInterval;
    private PropertyChangeSupport changer = new PropertyChangeSupport(this);

    public ReportingOutputStream(File f) throws IOException {
        fileStream = new FileOutputStream(f);
    }

    public void setUpdateInterval(long bytes) {
        updateInterval = bytes;
        nextReport = updateInterval;
    }

    @Override
    public void write(int b) throws IOException {
        byte[] bytes = { (byte) (b & 0xFF) };
        write(bytes, 0, 1);
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        fileStream.write(b, off, len);
        byteCount += len;
        if (byteCount > nextReport) {
            changer.firePropertyChange( BYTES_PROP, lastByteCount, byteCount);
            lastByteCount = byteCount;
            nextReport += updateInterval;
        }
    }

    @Override
    public void close() throws IOException {
        if (fileStream != null) {
            fileStream.close();
            fileStream = null;
        }
    }

    public void removePropertyChangeListener(String propertyName, PropertyChangeListener listener) {
        changer.removePropertyChangeListener(propertyName, listener);
    }

    public void addPropertyChangeListener(String propertyName, PropertyChangeListener listener) {
        changer.addPropertyChangeListener(propertyName, listener);
    }
}

创建流后，为BYTES_PROP添加属性更改侦听器。默认情况下，它会为收到的每1 KB触发处理程序。请致电setUpdateInterval进行更改。

Answer 2

由于retrieveFile和storeFile处理输入和输出流，您是否可以编写自己的子类来监视在一定时间内传入或传出的字节数？

Java：如何获得上传和下载速度

2 个答案: