UDP数据包.ppt

UDP实验 UDP编程(Java)：NetworkInterface Class java.net.NetworkInterface This class represents a Network Interface made up of a name, and a list of IP addresses assigned to this interface. It is used to identify the local interface on which a multicast group is joined. Interfaces are normally known by names such as le0. 常用：NetworkInterface.getNetworkInterfaces() 例如： EnumerationNetworkInterface eni = NetworkInterface.getNetworkInterfaces(); UDP编程(Java)：NetworkInterface getInetAddresses public EnumerationInetAddress getInetAddresses() Convenience method to return an Enumeration with all or a subset of the InetAddresses bound to this network interface. getInterfaceAddresses public ListInterfaceAddress getInterfaceAddresses() Get a List of all or a subset of the InterfaceAddresses of this network interface. Why both talk about subset? If there is a security manager, its checkConnect method is called for each InetAddress/InterfaceAddress. Only InetAddresses/InterfaceAddress where the checkConnect doesnt throw a SecurityException will be returned in the Enumeration. UDP编程(Java)：InterfaceAddress Class java.net.InterfaceAddress This class represents a Network Interface address. In short its an IP address, a subnet mask and a broadcast address when the address is an IPv4 one. An IP address and a network prefix length in the case of IPv6 address. 常用： getAddress() ：Returns an InetAddress for this address. getBroadcast() :Returns an InetAddress for the brodcast address for this InterfaceAddress. getNetworkPrefixLength() :Returns the network prefix length for this address. UDP编程(Java)：InetAddress Class java.net.InetAddress implements Serializable This class represents an Internet Protocol (IP) address. An IP address is either a 32-bit or 128-bit unsigned number used by IP. An instance of an InetAddress consists of an IP address and possibly its corresponding host name. 常用： static InetAddress getByName(String host)： Determines the IP address of a host, given the hosts name. Stri