Java网络编程之IP，端口号，通信协议（UDP，TCP）_Java

1.软件架构

2.网络编程三要素

3.ip

1.ipv4

2.ipv6

        //获取inetaddress的对象
        inetaddress address = inetaddress.getbyname("127.0.0.1");

4.端口号

5.协议

在这里插入图片描述

1.udp协议

udp协议发送数据：

public class send{
    public static void main(string[] args) throws ioexception {
        //创建datagramsocket对象
        datagramsocket ds = new datagramsocket();
        //打包数据
        string str = "你好！！";
        byte[] bytes = str.getbytes();
        inetaddress address = inetaddress.getbyname("127.0.0.1");
        int port = 10006;

        datagrampacket dp = new datagrampacket(bytes, bytes.length, address, port);
        //发送数据
        ds.send(dp);
        //释放资源
        ds.close();
    }
}

udp协议接收数据：

public class receive{
    public static void main(string[] args) throws ioexception {
        //创建datagramsocket对象：接收时绑定的端口号要与发送时的端口保持一致
        datagramsocket ds = new datagramsocket(10086);
        //接收数据包
        byte[] bytes = new byte[1024];
        datagrampacket dp = new datagrampacket(bytes, bytes.length);
        ds.receive(dp);
        //解析数据包
        byte[] data = dp.getdata();
        int length = dp.getlength();
        inetaddress address = dp.getaddress();
        int port = dp.getport();

        system.out.println("接收到数据：" + new string(data, 0, length));
        system.out.println("该数据是从" + address + "这台电脑中的" + port + "这个端口号发出的");
        //释放资源
        ds.close();
    }
}

1.单播

2.组播

3.广播

2.tcp协议

客户端发送数据：

public class client {
    public static void main(string[] args) throws ioexception {
        //发送数据
        //创建socket对象
        socket socket = new socket("127.0.0.1", 10001);
        //从连接通道中获取输出流
        outputstream os = socket.getoutputstream();
        //写出数据
        os.write("你好".getbytes());
        //释放资源
        os.close();
        socket.close();
    }
}

服务器接收数据：

public class server {
    public static void main(string[] args) throws ioexception {
        //接收数据
        //
        serversocket ss = new serversocket(10001);
        //监听用户的连接
        socket socket = ss.accept();
        //从连接通道中获取输入流数据
        inputstream is = socket.getinputstream();
        //解决中文乱码
        inputstreamreader isr = new inputstreamreader(is);
        //使用缓冲流提高读取效率
        bufferedreader br = new bufferedreader(isr);
        int b;
        while ((b = br.read()) != -1) {
            system.out.println((char) b);
        }
        //释放资源
        socket.close();
        ss.close();

    }
}