java使用UDP来进行客户端和服务器端通信的简单例子
1：客户端程序
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packagecom.pb.udp;
importjava.io.ioexception;
importjava.net.datagrampacket;
importjava.net.inetaddress;
importjava.net.unknownhostexception;
importjava.net.datagramsocket;
/**
*使用sender类来代表客户端程序，
*@authorccna_zhang
*
*/
publicclasssender{
publicstaticvoidmain(string[]args){
stringmsg="hello,world";
byte[]buf=msg.getbytes();
try{
inetaddressaddress=inetaddress.getbyname("192.168.1.80");//服务器地址
intport=8080;//服务器的端口号
//创建发送方的数据报信息
datagrampacketdatagrampacket=newdatagrampacket(buf,buf.length,address,port);
datagramsocketsocket=newdatagramsocket();//创建套接字
socket.send(datagrampacket);//通过套接字发送数据
//接收服务器反馈数据
byte[]backbuf=newbyte[1024];
datagrampacketbackpacket=newdatagrampacket(backbuf,backbuf.length);
socket.receive(backpacket);//接收返回数据
stringbackmsg=newstring(backbuf,0,backpacket.getlength());
system.out.println("服务器返回的数据为:"+backmsg);
socket.close();
}catch(unknownhostexceptione){
e.printstacktrace();
}catch(ioexceptione){
e.printstacktrace();
}
}
}
2：服务器端程序
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packagecom.pb.udp;
importjava.io.ioexception;
importjava.net.datagrampacket;
importjava.net.datagramsocket;
importjava.net.inetaddress;
importjava.net.socketaddress;
importjava.net.unknownhostexception;
/**
*服务器端程序
*@authorccna_zhang
*
*/
publicclassreceiver{
publicstaticvoidmain(string[]args){
try{
inetaddressaddress=inetaddress.getlocalhost();
intport=8080;
//创建datagramsocket对象
datagramsocketsocket=newdatagramsocket(port,address);
byte[]buf=newbyte[1024];//定义byte数组
datagrampacketpacket=newdatagrampacket(buf,buf.length);//创建datagrampacket对象
socket.receive(packet);//通过套接字接收数据
stringgetmsg=newstring(buf,0,packet.getlength());
system.out.println("客户端发送的数据为："+getmsg);
//从服务器返回给客户端数据
inetaddressclientaddress=packet.getaddress();//获得客户端的ip地址
intclientport=packet.getport();//获得客户端的端口号
socketaddresssendaddress=packet.getsocketaddress();
stringfeedback="received";
byte[]backbuf=feedback.getbytes();
datagrampacketsendpacket=newdatagrampacket(backbuf,backbuf.length,sendaddress);//封装返回给客户端的数据
socket.send(sendpacket);//通过套接字反馈服务器数据
socket.close();//关闭套接字
}catch(unknownhostexceptione){
e.printstacktrace();
}catch(ioexceptione){
e.printstacktrace();
}
}
}
3：程序运行结果
服务器端：
客户端发送的数据为：hello,world
客户端：
服务器返回的数据为:received