网络与通信 实验报告2.docVIP

网络与通信课程实验报告实验2：Socket通信编程姓名 院系计算机学院学号 任课教师钱权指导教师钱权实验地点行健楼603实验时间一3-4实验课表现出勤、表现得分(10)实验报告得分(40)实验总分操作结果得分(50)实验目的：1. 掌握Socket编程过程；2. 编写简单的网络应用程序。实验内容：利用你选择的任何一个编程语言，分别基于TCP 和UDP 编写一个简单的Client/Server 网络应用程序。具体程序要求参见实验指导书。要求以附件形式给出：l 系统概述：运行环境、编译、使用方法、实现环境、程序文件列表等；l 主要数据结构；l 主要算法描述； l 用户使用手册；l 程序源代码；实验要求：（学生对预习要求的回答）（10分）得分：l Socket编程客户端的主要步骤l Socket编程服务器端的主要步骤实验过程中遇到的问题如何解决的？（10分）得分：问题1：在编写Socket程序时如何使客户端与服务端建立连接？在Socket的服务器端口，建立一个死循环，不断的监听客户端所发送的connect()请求，当有相应的请求到来时，建立连接，退出死循环。问题2：连接简历后如何传送字符传？通过Socket自带的send()和receive()函数，实现客户端与服务器的信息交流发送。在设置相应的一对发送函数时，要注意相对应的函数循序，否则可能导致死锁。问题3：在已成功发送数据之后，出现receive()函数返回值为0。在完成发送之后，如果调用close()函数，则相关的发送字节数将被清零。本次实验的体会（结论）（10分）得分：通过这次对Socket 的编程，我对Socket的工作原理有了更深入的认识与理解，并提高了自身的编程水平，同时在学习能力上有了更大的进步。通过这次的学习与认知，基本已经掌握并能较为熟练的编写socket程序，虽然过程中遇到了不少问题，但是，对自身的提高还是益处良多的。思考题：（10分）思考题1：（4分）得分：你所用的编程语言在Socket通信中用到的主要类及其主要作用。在这次的编写Socket程序中，主要用到了java语言，实现了对Socket的定义到连接再到通信的全过程。思考题2：（6分）得分：说明TCP和UDP编程的主要差异和特点。TCP是有连接传送方式，在进行通信之前，需要先建立连接，相关信息交流函数为send()和receive()，其中不用给出相应的发送或接收地址。UDP是无连接传送方式，在通信之前无需建立连接，相关的交流函数为sendto()和receivefrom()，其中需要给出相应的发送或接收地址。指导教师评语：日期： 程序源代码：TCP：package tcp;import .*;import java.io.*;import java.util.*;public class Client public static void main(String args) throws IOException Socket s = new Socket(localhost, 30000); String flag = ; Scanner scan = new Scanner(s.getInputStream(); if (scan.hasNextLine() flag = scan.nextLine().trim(); if (ok.equals(flag) File file = new File(d:a.txt); if (!file.exists() | !file.isFile() System.out.println(File + args2 + does not exist or is not a normal file.); System.exit(0); DataOutputStream out = new DataOutputStream(s.getOutputStream(); out.writeUTF(aaaaaaaaaaaaaa); out.writeLong(file.length(); FileInputStream in = null; try in = new FileInputStream(file); byte buffer = new byte1024 * 8; int len = -1; System.out.println(File tansfer start.); while (len = in.read(buffer) != -1) out.write(buffer, 0, len); System.out.println(File tansfer complete.); catch (Exception e) System.out.println(Error: + e.getMessage(); System.exit(1); finally try if (in != null) in.close(); catch (Exception e) out.writeUTF(bbbbbbbbbb); if (out != null) out.close(); if (scan != null) scan.close(); if (s != null) s.close();package tcp;import java.io.DataInputStream;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.PrintStream;import .ServerSocket;import .Socket;public class Server extends Thread public static void main(String args) throws IOException boolean isStop = false; ServerSocket ss = null; try ss = new ServerSocket(30000); while (!isStop) Socket socket = ss.accept(); PrintStream ps1 = new PrintStream(socket.getOutputStream(); ps1.println(ok); ps1.flush(); InputStream in = socket.getInputStream(); DataInputStream dis = new DataInputStream(in); String head = dis.readUTF(); Long length = dis.readLong(); System.out.println(head); System.out.println(length); File file = new File(e:a.txt); if (!file.exists() file.createNewFile(); try FileOutputStream out = new FileOutputStream(file); byte buffer = new byte1024 * 8; int len = -1; Long n = 0l; while (len = dis.read(buffer) != -1) out.write(buffer, 0, len); n += len; if (n + 1024 * 8) length) int lastLen = (int) (length - n); len = dis.read(buffer, 0, lastLen); out.write(buffer, 0, len); break; catch (Exception e) System.out.println(Error: + e.getMessage(); String anotherhead = dis.readUTF(); System.out.println(anotherhead); try if (in != null) in.close(); catch (Exception e) socket.close(); catch (Exception e) UDP：package udp;import java.io.*; import java.awt.*; import java.awt.event.*; import .*; public class chata extends Frame implements ActionListener Label label = new Label(发言); Panel panel = new Panel(); TextField tf = new TextField(10); TextArea ta = new TextArea(); public chata() super(A方); setSize(250,250); panel.add(label); panel.add(tf); tf.addActionListener(this); add(North,panel); add(Center,ta); addWindowListener(new WindowAdapter() public void windowClosing(WindowEvent e)System.exit(0);); show(); /startup listener Listener listener = new Listener(); Thread thread = new Thread(listener); thread.start(); public void actionPerformed(ActionEvent e) /把要说的话发出去 String str = tf.getText(); byte buf = str.getBytes(); tf.setText(null); ta.append(我说:+str); ta.append(n); try DatagramSocket socket = new DatagramSocket(); DatagramPacket packet = new DatagramPacket(buf,buf.length); InetAddress remote_addr = InetAddress.getByName(localhost); packet.setAddress(remote_addr); /send to remote port 8877 packet.setPort(8877); socket.send(packet); catch (UnknownHostException uhe) System.out.println(Unknown Host!); catch (IOException ioe) System.out.println(IO Error!); class Listener implements Runnable public void run() try for(;) /监听本地端口8888 DatagramSocket socket = new DatagramSocket(8888); DatagramPacket packet = new DatagramPacket(new byte256, 256); socket.receive(packet); ByteArrayInputStream bin = new ByteArrayInputStream(packet.getData(); DataInputStream din = new DataInputStream(bin); String str = din.readLine(); ta.append(对方说：+str); ta.append(n); socket.close(); catch (IOException ioe) System.out.println(IO Error!); public static void main(String args) chata a = new chata(); package udp;import java.io.*; import java.awt.*; import java.awt.event.*; import .*; public class chatb extends Frame implements ActionListener Label label = new Label(发言); Panel panel = new Panel(); TextField tf = new TextField(10); TextArea ta = new TextArea(); public chatb() super(B方); setSize(250,250); panel.add(label); panel.add(tf); tf.addActionListener(this); add(North,panel); add(Center,ta); addWindowListener(new WindowAdapter() public void windowClosing(WindowEvent e)System.exit(0);); show(); /startup listener Listener listener = new Listener(); Thread thread = new Thread(listener); thread.start(); public void actionPerformed(ActionEvent e) /把要说的话发出去 String str = tf.getText(); byte buf = str.getBytes(); tf.setText(null); ta.append(我说:+str); ta.append(n); try DatagramSocket socket = new DatagramSocket(); DatagramPacket packet = new DatagramPacket(buf,buf.length); InetAddress remote_addr = InetAddress.getByName(localhost); packet.setAddress(remote_addr); /send to remote port