java网络编程应该怎样在客户端和服务器间实现通信？

以前写的，照贴了。。。服务器端：import java.awt.*\x0d\x0aimport java.awt.event.WindowAdapter\x0d\x0aimport java.awt.event.WindowEvent\x0d\x0aimport java.io.*\x0d\x0aimport java.net.*/*6、 采用UDP协议，编写一个Java网络应用程序，该应用分服务器端程序和客户端程序两部分。\x0d\x0a* 客户端指定一个服务器上的文件名，让服务器发回该文件的内容，或者提示文件不存在。\x0d\x0a* （20分）（服务端程序和客户端程序分别命名为Server.java和Client.java）*/\x0d\x0apublic class N4BT6 extends Frame\x0d\x0a{\x0d\x0aDatagramSocket socket \x0d\x0aDatagramPacket packet byte[] buf \x0d\x0aFile file \x0d\x0aFileInputStream input\x0d\x0aString message = "该文件不存在"\x0d\x0aTextArea text\x0d\x0apublic N4BT6(String title)\x0d\x0a{\x0d\x0asuper(title)\x0d\x0atext = new TextArea(6,4)\x0d\x0aadd(text)\x0d\x0asetSize(400, 300)\x0d\x0asetVisible(true)\x0d\x0aaddWindowListener(new WindowAdapter()\x0d\x0a{\x0d\x0apublic void windowClosing(WindowEvent e)\x0d\x0a{\x0d\x0adispose()\x0d\x0a}\x0d\x0a})\x0d\x0a\x0d\x0abuf = new byte[1024]\x0d\x0atry\x0d\x0a{\x0d\x0asocket = new DatagramSocket(1230)\x0d\x0apacket = new DatagramPacket(buf, buf.length)\x0d\x0asocket.receive(packet)\x0d\x0afile = new File(new String(packet.getData()))\x0d\x0asocket = new DatagramSocket()\x0d\x0a} \x0d\x0acatch (Exception e)\x0d\x0a{e.printStackTrace()\x0d\x0a}\x0d\x0a\x0d\x0aif(file.exists())\x0d\x0a{\x0d\x0atry\x0d\x0a{\x0d\x0abuf = new byte[(int)file.length()]\x0d\x0apacket = new DatagramPacket(buf,buf.length,InetAddress.getLocalHost(),1234)\x0d\x0ainput = new FileInputStream(file)\x0d\x0ainput.read(buf)\x0d\x0asocket.send(packet)\x0d\x0a}\x0d\x0acatch (IOException e) \x0d\x0a{\x0d\x0ae.printStackTrace()\x0d\x0a}\x0d\x0a}\x0d\x0aelse\x0d\x0a{\x0d\x0atry\x0d\x0a{\x0d\x0apacket = new DatagramPacket(message.getBytes(),message.getBytes().length,\x0d\x0aInetAddress.getLocalHost(),1234)\x0d\x0asocket.send(packet)\x0d\x0a}\x0d\x0acatch (Exception e) \x0d\x0a{\x0d\x0ae.printStackTrace()\x0d\x0a}\x0d\x0a}\x0d\x0a\x0d\x0a}\x0d\x0apublic static void main(String[] args)\x0d\x0a{\x0d\x0anew N4BT6("Server")\x0d\x0a}\x0d\x0a}\x0d\x0a客户端：import java.awt.*\x0d\x0aimport java.awt.event.*\x0d\x0aimport java.net.DatagramPacket\x0d\x0aimport java.net.DatagramSocket\x0d\x0aimport java.net.InetAddresspublic class N4BT6_2 extends Frame\x0d\x0a{\x0d\x0aTextArea text\x0d\x0aString message = "Q.txt"\x0d\x0aDatagramSocket socket \x0d\x0aDatagramPacket packet\x0d\x0abyte[] buf\x0d\x0apublic N4BT6_2(String title)\x0d\x0a{\x0d\x0asuper(title)\x0d\x0atext = new TextArea(6,4)\x0d\x0aadd(text)\x0d\x0asetSize(400, 300)\x0d\x0asetVisible(true)\x0d\x0aaddWindowListener(new WindowAdapter()\x0d\x0a{\x0d\x0apublic void windowClosing(WindowEvent e)\x0d\x0a{\x0d\x0adispose()\x0d\x0a}\x0d\x0a})\x0d\x0atry\x0d\x0a{\x0d\x0a\x0d\x0asocket = new DatagramSocket()\x0d\x0apacket = new DatagramPacket(message.getBytes(),message.getBytes().length,\x0d\x0aInetAddress.getLocalHost(),1230)\x0d\x0asocket.send(packet)\x0d\x0a}\x0d\x0acatch (Exception e) \x0d\x0a{\x0d\x0ae.printStackTrace()\x0d\x0a}\x0d\x0a\x0d\x0atry\x0d\x0a{\x0d\x0abuf = new byte[1024]\x0d\x0asocket = new DatagramSocket(1234)\x0d\x0apacket = new DatagramPacket(buf,buf.length)\x0d\x0asocket.receive(packet)\x0d\x0atext.append(new String(buf))\x0d\x0a}\x0d\x0acatch (Exception e) \x0d\x0a{\x0d\x0ae.printStackTrace()\x0d\x0a}\x0d\x0a}\x0d\x0apublic static void main(String[] args)\x0d\x0a{\x0d\x0anew N4BT6_2("Client")\x0d\x0a}\x0d\x0a}

先发服务端的（Server)完整代码如下：

引入命名空间：

[csharp] view plain copy print?

using System.Net.Sockets

using System.Net

using System.Threading

完整代码如下：

[csharp] view plain copy print?

namespace SocketServer

{

class Program

{

private static byte[] result = new byte[1024]

private static int myProt = 8885 //端口

static Socket serverSocket

static void Main(string[] args)

{

//服务器IP地址

IPAddress ip = IPAddress.Parse("127.0.0.1")

serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)

serverSocket.Bind(new IPEndPoint(ip, myProt)) //绑定IP地址：端口

serverSocket.Listen(10) //设定最多10个排队连接请求

Console.WriteLine("启动监听{0}成功", serverSocket.LocalEndPoint.ToString())

//通过Clientsoket发送数据

Thread myThread = new Thread(ListenClientConnect)

myThread.Start()

Console.ReadLine()

}

/// <summary>

/// 监听客户端连接

/// </summary>

private static void ListenClientConnect()

{

while (true)

{

Socket clientSocket = serverSocket.Accept()

clientSocket.Send(Encoding.ASCII.GetBytes("Server Say Hello"))

Thread receiveThread = new Thread(ReceiveMessage)

receiveThread.Start(clientSocket)

}

}

/// <summary>

/// 接收消息

/// </summary>

/// <param name="clientSocket"></param>

private static void ReceiveMessage(object clientSocket)

{

Socket myClientSocket = (Socket)clientSocket

while (true)

{

try

{

//通过clientSocket接收数据

int receiveNumber = myClientSocket.Receive(result)

Console.WriteLine("接收客户端{0}消息{1}", myClientSocket.RemoteEndPoint.ToString(), Encoding.ASCII.GetString(result, 0, receiveNumber))

}

catch(Exception ex)

{

Console.WriteLine(ex.Message)

myClientSocket.Shutdown(SocketShutdown.Both)

myClientSocket.Close()

break

}

}

}

}

}

以上是服务端（server）的完整代码。

客户端（Client）的完整代码如下：

引入命名空间：

[csharp] view plain copy print?

using System.Net

using System.Net.Sockets

using System.Threading

完整代码：

[csharp] view plain copy print?

namespace SocketClient

{

class Program

{

private static byte[] result = new byte[1024]

static void Main(string[] args)

{

//设定服务器IP地址

IPAddress ip = IPAddress.Parse("127.0.0.1")

Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)

try

{

clientSocket.Connect(new IPEndPoint(ip, 8885))//配置服务器IP与端口

Console.WriteLine("连接服务器成功")

}

catch

{

Console.WriteLine("连接服务器失败，请按回车键退出！")

return

}

//通过clientSocket接收数据

int receiveLength = clientSocket.Receive(result)

Console.WriteLine("接收服务器消息：{0}",Encoding.ASCII.GetString(result,0,receiveLength))

//通过 clientSocket 发送数据

for (int i = 0i <10i++)

{

try

{

Thread.Sleep(1000) //等待1秒钟

string sendMessage = "client send Message Hellp" + DateTime.Now

clientSocket.Send(Encoding.ASCII.GetBytes(sendMessage))

Console.WriteLine("向服务器发送消息：{0}" + sendMessage)

}

catch

{

clientSocket.Shutdown(SocketShutdown.Both)

clientSocket.Close()

break

}

}

Console.WriteLine("发送完毕，按回车键退出")

Console.ReadLine()

}

}

}

编译成功后，先运行 服务端（server），再运行客户端（client）即可达到通信效果。

效果如下图：

该程序已在局域网测试通过。（192.168.X.X）

Socket通信：

作为服务器端:

//生成服务器端,监听服务器设定的端口

ServerSocket

socketServer

=

new

ServerSocket(端口号)

//建立客户端和服务器端的链接，这时再看客户端

Socket

socket

=

socketServer.accept()

作为客户端:

//新建一个Socket，包含服务器端的IP和端口号，这样在服务器启动情况下可以建立和服务器的链接.

Socket

socket

=

new

Socket（"IP地址","端口号"）

这时,服务器端和客户端的连接已经建立,如果需要通信和传输数据的话分别在服务器端、客户端新建流对象，可以通过流对象实现双方之间的互通.

有关流的内容自己看书体会下就能写出B/S结构的通信了。

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