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javaniodatagram

DatagramChannel receive may not return SocketAddress

According to the Javadoc for DatagramChannel the receive method: 

public abstract SocketAddress receive(ByteBuffer dst)
                           throws IOException

may return null if the DatagramChannel is in non-blocking mode. Other than changing to blocking mode is there a way to ensure I get the SocketAddress for the data I read?

Solution

  • may return null if the DatagramChannel is in non-blocking mode.

    Read on.

    Returns ... null if this channel is in non-blocking mode and no datagram was immediately available.

    If it returned null there was no data read. The situation corresponds to SocketChannel.read() returning zero.