最近尝试让easylink3在热点模式下连接，发现用普通的广播地址会报错，Network unreachable
尝试按照*上的方法：
public static int getCodecIpAddress(WifiManager wm, NetworkInfo wifi){
WifiInfo wi = wm.getConnectionInfo();
if(wifi.isConnected())
return wi.getIpAddress(); //normal wifi
Method method = null;
try {
method = wm.getClass().getDeclaredMethod("getWifiApState");
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if(method != null)
method.setAccessible(true);
int actualState = -1;
try {
if(method!=null)
actualState = (Integer) method.invoke(wm, (Object[]) null);
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
if(actualState==13){ //if wifiAP is enabled
return convertIP2Int("192.168.43.1".getBytes()); //hardcoded WifiAP ip
}
return 0;
}
public static int convertIP2Int(byte[] ipAddress){
return (int) (Math.pow(256, 3)*Integer.valueOf(ipAddress[3] & 0xFF)+Math.pow(256, 2)*Integer.valueOf(ipAddress[2] & 0xFF)+256*Integer.valueOf(ipAddress[1] & 0xFF)+Integer.valueOf(ipAddress[0] & 0xFF));
}
private InetAddress getBroadcastAddress(WifiManager wm, int ipAddress) throws IOException {
DhcpInfo dhcp = wm.getDhcpInfo();
if(dhcp == null)
return InetAddress.getByName("255.255.255.255");
int broadcast = (ipAddress & dhcp.netmask) | ~dhcp.netmask;
byte[] quads = new byte[4];
for (int k = 0; k < 4; k++)
quads[k] = (byte) ((broadcast >> k * 8) & 0xFF);
return InetAddress.getByAddress(quads);
}
但是发现wm.getDhcpInfo得到的mask不对，是0
这样最终广播地址会是255.255.255.255
再次修正，将mask强行变为0.0.0.255之后，可以成功进行广播
但是多播还是不行，需要继续研究
update ----------------------
多播也ok了，参考这篇文章：https://plus.google.com/+Chainfire/posts/9NMemrKYnCd
在热点模式下，默认的networkinterface是不对的，需要使用MulticastSocket::setNetworkInterface()来指定wlan作为多播interface