ios UDP组播

这几天在做wifi的智能灯，需要用到组播的知识就把这个记录一下，服务端使用java写的，代码如下：

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.MulticastSocket;

 class UDPServer{
    public static void main(String[] args)throws IOException{
        MulticastSocket  server = new MulticastSocket(5050);
        InetAddress address = InetAddress.getByName("224.0.0.1");
        server.joinGroup(address);
        
        
        byte[] recvBuf = new byte[100];
        DatagramPacket recvPacket 
            = new DatagramPacket(recvBuf , recvBuf.length);
        
        while(true)
        {
        
        server.receive(recvPacket);
        String recvStr = new String(recvPacket.getData() , 0 , recvPacket.getLength());
        System.out.println("Hello World!" + recvStr);
        int port = recvPacket.getPort();
        InetAddress addr = InetAddress.getByName("224.0.0.1");
        String sendStr = "Hello ! I'm Server";
        byte[] sendBuf;
        sendBuf = sendStr.getBytes();
        DatagramPacket sendPacket 
            = new DatagramPacket(sendBuf , sendBuf.length , addr , port );
        server.send(sendPacket);
        }
     
        
        
    }
    
}

ios端的主要代码：

#import "UdpHelper.h"

@implementation UdpHelper {
    AsyncUdpSocket* m_udpSocket;
}

+ (UdpHelper*)getinstance
{

    static UdpHelper* udpHelper = nil;

    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
            udpHelper = [[self alloc] init];
        
        [udpHelper openUDPServer];
    });

    return udpHelper;
}

- (void)openUDPServer
{
    AsyncUdpSocket* tempSocket = [[AsyncUdpSocket alloc] initWithDelegate:self];
    m_udpSocket = tempSocket;

    NSError* error = nil;
    [m_udpSocket bindToPort:5051 error:&error];
    [m_udpSocket joinMulticastGroup:@"224.0.0.1" error:&error];

    [m_udpSocket receiveWithTimeout:-1 tag:0];
}

- (void)sendMessage:(NSString*)message
{
    NSMutableString* sendString = [NSMutableString stringWithCapacity:100];
    [sendString appendString:message];

    BOOL res = [m_udpSocket sendData:[sendString dataUsingEncoding:NSUTF8StringEncoding]
                              toHost:@"224.0.0.1"
                                port:5050
                         withTimeout:-1
                                 tag:0];

    NSLog(@"%@", sendString);
    if (res) {
        NSLog(@"xxxxffff");
    }
    else {
        NSLog(@"error");
    }
}

- (BOOL)onUdpSocket:(AsyncUdpSocket*)sock didReceiveData:(NSData*)data withTag:(long)tag fromHost:(NSString*)host port:(UInt16)port
{
    NSLog(@"onUdpSocket successful");

    NSString* str = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

    NSLog(@"%@", str);

    return YES;
}

- (void)onUdpSocket:(AsyncUdpSocket*)sock didNotSendDataWithTag:(long)tag dueToError:(NSError*)error
{
    NSLog(@"error1");
}

- (void)onUdpSocket:(AsyncUdpSocket*)sock didNotReceiveDataWithTag:(long)tag dueToError:(NSError*)error
{
    NSLog(@"error2");
}

@end

以上的代码就可以实现两端互发消息通信，代码也主要是借鉴了一些别人的