package ChatClient;
import java.net.*;
import java.io.*;
public class ChatClient{
private DatagramSocket s;
private InetAddress hostAddress;
private byte[] buf = new byte[1000];
private DatagramPacket dp = new DatagramPacket(buf,buf.length);
//方法说明：构造器，这里实现接收用户输入和与服务器通讯
public ChatClient(){
try{
//使用构造器，创建使用本机任何可用端口的数据包Socket
s = new DatagramSocket();
//获取本地IP
hostAddress = InetAddress.getByName("localhost");
while(true){
String outMessage ="";
//读取输入
BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
try{
outMessage = stdin.readLine();
}catch(IOException ie){ System.err.println("IO error!"); }
//如果输入“bye”则表示退出程序
if(outMessage.equals("bye")) break;
String outString = "Client say: "+ outMessage;
byte[] buf = outString.getBytes();
//打包数据，发送数据
DatagramPacket out = new DatagramPacket(buf,buf.length,hostAddress,4000);
s.send(out);
//等待服务器返回
s.receive(dp);
String rcvd = "rcvd from "+ dp.getAddress() + ", " + dp.getPort() +
": "+ new String(dp.getData(),0,dp.getLength());
System.out.println(rcvd);
}
}catch(UnknownHostException e){
System.out.println("Can;t open socket");
System.exit(1);
}catch(SocketException e){
System.out.println("Can;t open socket");
e.printStackTrace();
System.exit(1);
}catch(IOException e){
System.err.println("Communication error");
e.printStackTrace();
System.exit(1);
}catch(Exception e){
System.err.println("Communication error");
e.printStackTrace();
System.exit(1);
}
System.out.println("ChatClient over");
}
public static void main(String[] args){ new ChatClient(); }
}
