用JAVA 编写简单网络聊天程序

/**

* 基于UDP协议的聊天程序

*

*2007.9.18

* */

//导入包

import java.awt.*

import java.awt.event.*

import java.awt.event.ActionEvent

import java.awt.event.ActionListener

import javax.swing.*

import java.net.*

public class Chat extends JFrame implements ActionListener

{

//广播地址或者对方的地址

public static final String sendIP = "172.18.8.255"

//发送端口9527

public static final int sendPort = 9527

JPanel p = new JPanel()

List lst = new List() //消息显示

JTextField txtIP = new JTextField(18)//填写IP地址

JTextField txtMSG = new JTextField(20)//填写发送消息

JLabel lblIP = new JLabel("IP地址:")

JLabel lblMSG = new JLabel("消息:")

JButton btnSend = new JButton("发送")

byte [] buf

//定义DatagramSocket的对象必须进行异常处理

//发送和接收数据报包的套接字

DatagramSocket ds = null

//=============构造函数=====================

public Chat()

{

CreateInterFace()

//注册消息框监听器

txtMSG.addActionListener(this)

btnSend.addActionListener(this)

try

{

//端口:9527

ds =new DatagramSocket(sendPort)

}

catch(Exception ex)

{

ex.printStackTrace()

}

//============接受消息============

//匿名类

new Thread(new Runnable()

{

public void run()

{

byte buf[] = new byte[1024]

//表示接受数据报包

while(true)

{

try

{

DatagramPacket dp = new DatagramPacket(buf,1024,InetAddress.getByName(txtIP.getText()),sendPort)

ds.receive(dp)

lst.add("【消息来自】◆" + dp.getAddress().getHostAddress() + "◆"+"【说】:" + new String (buf,0,dp.getLength()) /*+ dp.getPort()*/,0)

}

catch(Exception e)

{

if(ds.isClosed())

{

e.printStackTrace()

}

}

}

}

}).start()

//关闭窗体事件

this.addWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent w)

{

System.out.println("test")

int n=JOptionPane.showConfirmDialog(null,"是否要退出?","退出",JOptionPane.YES_NO_OPTION)

if(n==JOptionPane.YES_OPTION)

{

dispose()

System.exit(0)

ds.close()//关闭ds对象//关闭数据报套接字

}

}

})

}

//界面设计布局

public void CreateInterFace()

{

this.add(lst,BorderLayout.CENTER)

this.add(p,BorderLayout.SOUTH)

p.add(lblIP)

p.add(txtIP)

p.add(lblMSG)

p.add(txtMSG)

p.add(btnSend)

txtIP.setText(sendIP)

//背景颜色

lst.setBackground(Color.yellow)

//JAVA默认风格

this.setUndecorated(true)

this.getRootPane().setWindowDecorationStyle(JRootPane.FRAME)

this.setSize(600,500)

this.setTitle("〓聊天室〓")

this.setResizable(false)//不能改变窗体大小

this.setLocationRelativeTo(null)//窗体居中

this.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE)

this.setVisible(true)

txtMSG.requestFocus()//消息框得到焦点

}

//===============================Main函数===============================

public static void main(String[]args)

{

new Chat()

}

//================================发送消息===============================

//消息框回车发送消息事件

public void actionPerformed(ActionEvent e)

{

//得到文本内容

buf = txtMSG.getText().getBytes()

//判断消息框是否为空

if (txtMSG.getText().length()==0)

{

JOptionPane.showMessageDialog(null,"发送消息不能为空","提示",JOptionPane.WARNING_MESSAGE)

}

else{

try

{

InetAddress address = InetAddress.getByName(sendIP)

DatagramPacket dp = new DatagramPacket(buf,buf.length,InetAddress.getByName(txtIP.getText()),sendPort)

ds.send(dp)

}

catch(Exception ex)

{

ex.printStackTrace()

}

}

txtMSG.setText("")//清空消息框

//点发送按钮发送消息事件

if(e.getSource()==btnSend)

{

buf = txtMSG.getText().getBytes()

try

{

DatagramPacket dp = new DatagramPacket(buf,buf.length,InetAddress.getByName(txtIP.getText()),sendPort)

}

catch(Exception ex)

{

ex.printStackTrace()

}

txtMSG.setText("")//清空消息框

txtMSG.requestFocus()

}

}

}

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

#include<errno.h>

#include<sys/socket.h>

#include<arpa/inet.h>

#include<netinet/in.h>

#include<sys/types.h>

#include<unistd.h>

#include<sys/time.h>

#defineBUFLEN1024

#definePORT6666

#defineLISTNUM20

intmain()

{

intsockfd,newfd

structsockaddr_ins_addr,c_addr

charbuf[BUFLEN]

socklen_tlen

unsignedintport,listnum

fd_setrfds

structtimevaltv

intretval,maxfd

/*建立socket*/

if((sockfd=socket(PF_INET,SOCK_STREAM,0))==-1){

perror("socket")

exit(errno)

}else

printf("socketcreatesuccess!\n")

memset(&s_addr,0,sizeof(s_addr))

s_addr.sin_family=AF_INET

s_addr.sin_port=htons(PORT)

s_addr.sin_addr.s_addr=htons(INADDR_ANY)

/*把地址和端口帮定到套接字上*/

if((bind(sockfd,(structsockaddr*)&s_addr,sizeof(structsockaddr)))==-1){

perror("bind")

exit(errno)

}else

printf("bindsuccess!\n")

/*侦听本地端口*/

if(listen(sockfd,listnum)==-1){

perror("listen")

exit(errno)

}else

printf("theserverislistening!\n")

while(1){

printf("*****************聊天开始***************\n")

len=sizeof(structsockaddr)

if((newfd=accept(sockfd,(structsockaddr*)&c_addr,&len))==-1){

perror("accept")

exit(errno)

}else

printf("正在与您聊天的客户端是：%s:%d\n",inet_ntoa(c_addr.sin_addr),ntohs(c_addr.sin_port))

while(1){

FD_ZERO(&rfds)

FD_SET(0,&rfds)

maxfd=0

FD_SET(newfd,&rfds)

/*找出文件描述符集合中最大的文件描述符*/

if(maxfd<newfd)

maxfd=newfd

/*设置超时时间*/

tv.tv_sec=6

tv.tv_usec=0

/*等待聊天*/

retval=select(maxfd+1,&rfds,NULL,NULL,&tv)

if(retval==-1){

printf("select出错，与该客户端连接的程序将退出\n")

break

}elseif(retval==0){

printf("waiting...\n")

continue

}else{

/*用户输入信息了*/

if(FD_ISSET(0,&rfds)){

/******发送消息*******/

memset(buf,0,sizeof(buf))

/*fgets函数：从流中读取BUFLEN-1个字符*/

fgets(buf,BUFLEN,stdin)

/*打印发送的消息*/

//fputs(buf,stdout)

if(!strncasecmp(buf,"quit",4)){

printf("server请求终止聊天!\n")

break

}

len=send(newfd,buf,strlen(buf),0)

if(len>0)

printf("\t消息发送成功：%s\n",buf)

else{

printf("消息发送失败!\n")

break

}

}

/*客户端发来了消息*/

if(FD_ISSET(newfd,&rfds)){

/******接收消息*******/

memset(buf,0,sizeof(buf))

/*fgets函数：从流中读取BUFLEN-1个字符*/

len=recv(newfd,buf,BUFLEN,0)

if(len>0)

printf("客户端发来的信息是：%s\n",buf)

else{

if(len<0)

printf("接受消息失败！\n")

else

printf("客户端退出了，聊天终止！\n")

break

}

}

}

}

/*关闭聊天的套接字*/

close(newfd)

/*是否退出服务器*/

printf("服务器是否退出程序：y->是；n->否?")

bzero(buf,BUFLEN)

fgets(buf,BUFLEN,stdin)

if(!strncasecmp(buf,"y",1)){

printf("server退出!\n")

break

}

}

/*关闭服务器的套接字*/

close(sockfd)

return0

}

扩展资料

C语言编写一个简单的ATM系统

#include<stdio.h>

intchoice

intshow_menu()

doubleget_money()

voiddeposit(double)

voidwithdraw(double)

doubleaccount=0.0

intmain(intargc,constchar*argv[])

{

system("COLOR5f")

show_menu()

doubletemp

while(choice!=0)

{

system("cls")

switch(choice)

{

case1:

printf("您的当前余额为:%.2f\n",get_money())

break

case2:

printf("请输入您的存款金额:\n")

scanf("%lf",&temp)

deposit(temp)

printf("您的当前余额为:%.2f\n",get_money())

break

case3:

printf("您的当前余额为:%.2f\n",get_money())

printf("请输入您的取款金额:\n")

scanf("%lf",&temp)

withdraw(temp)

printf("您的当前余额为:%.2f\n",get_money())

break

default:

break

}

getchar()

choice=show_menu()

}

printf("欢迎您下次再来中国银行为您提供的服务，再见！\n")

return0

}

intshow_menu()

{

printf("*****欢迎使用中国银行行为为您提供的服务******\n")

printf("\n1.查询账户余额2.存款3.取款0.退出\n")

printf("\n请选择服务种类：")

scanf("%d",&choice)

returnchoice

}

doubleget_money()

{

returnaccount

}

voiddeposit(doublemoney)

{

account=account+money

}

voidwithdraw(doublemoney)

{

if(account<money)

printf("抱歉，余额不足，不能取%.2f这么多钱!\n",money)

else

account=account-money

}

---