网络程序设计代码.docx

通过 getLocalHost()方法获得本地信息import .*; import java.util.*; class Exp13_2 public static void main (String args) throws UnknownHostException InetAddress localAddress = InetAddress.getLocalHost(); System.out.println(localAddress); System.out.println(localAddress.getHostName(); /获得主机名称 该例程使用InetAddress类，用于获得指定的计算机名称和IP地址，在该程序示例中，需要将各注释程序段一一测试运行。import .*;import java.util.*;class InetAddressDemopublic static void main (String args) throws UnknownHostException/获得本地主机信息/*InetAddress localAddress = InetAddress.getLocalHost();System.out.println(localAddress);*/获得本地hosts文件中的纪录主机/*String host = ;InetAddress address = InetAddress.getByName(host);System.out.println(address);*/根据指定域名获得IP/*String host = ;InetAddress addresses = InetAddress.getAllByName(host);for(InetAddress address : addresses)System.out.println(address);*/获得指定主机信息String host = localhost;if (args.length = 1)host = args 0;InetAddress ia = InetAddress.getByName (host);System.out.println (Canonical Host Name = + ia.getCanonicalHostName ();System.out.println (Host Address = + ia.getHostAddress ();System.out.println (Host Name = + ia.getHostName ();System.out.println (Is Loopback Address = + ia.isLoopbackAddress ();/获得本地主机所有IP地址/* Enumeration netInterfaces = null; try netInterfaces = NetworkInterface.getNetworkInterfaces(); while (netInterfaces.hasMoreElements() NetworkInterface ni = netInterfaces.nextElement(); System.out.println(DisplayName: + ni.getDisplayName(); System.out.println(Name: + ni.getName(); Enumeration ips = ni.getInetAddresses(); while (ips.hasMoreElements() System.out.println(IP: + ips.nextElement().getHostAddress(); catch (Exception e) e.printStackTrace(); */ /根据IP地址构造InetAddress /*byte ip = new byte (byte) 202, (byte) 117, (byte)128 , 7;InetAddress address1 = InetAddress.getByAddress(ip);InetAddress address2 = InetAddress.getByAddress(, ip);System.out.println(address1);System.out.println(address2);*/ 1）UDP时钟校对，该程序实例中包括2段程序，分别运行在2个不同的进程上，如果在一台计算机上运行，注意为服务器端和客户端设置不同的UDP端口以免冲突。1）UDP时钟校对服务端点程序import java.io.*;import .*;import java.util.*;/ 引入工具库， 提供日期和时间类public class DatagramServerpublic static void main(String args ) throws IOException/ 新建立一个服务器线程对象new QuoteServerThread().start();class QuoteServerThread extends Thread/ 定义一个服务器线程/ 新建一个DatagramSocket对象， 通信连接private DatagramSocket socket = null;/ 新建数据输入对象， 向网络输入private DataInputStream in = null;/ 循环控制，保证时间服务器长期运行private boolean moreQuotes = true;public QuoteServerThread() throws IOException/ 时间服务器构造方法super(QuoteServerThread);/ 在1080端口建立监听socket = new DatagramSocket(1080);public void run()/ 线程运行主方法while(moreQuotes)/ 无限循环发送时间信息trybyte buf = new byte256; /开辟数据缓冲区 ，256 byte 用于接收和发送数据/ 建立一个DatagramPacket,指向buf缓冲区，容量256， 用于接收数据DatagramPacket packet = new DatagramPacket(buf, buf.length);socket.receive(packet);/ 接收数据System.out.println(当前的数据： + new String(packet.getData();/获取时间日期String dString = new String( + Calendar.HOUR + Calendar.MINUTE); / 将string数据转换为bytedString.getBytes(0, dString.length(), buf, 0); / 目标IP, 已收到数据报的发送IP InetAddress address = packet.getAddress();int port = packet.getPort();/ 目标PORT/ 形成待发送数据报packet = new DatagramPacket(buf, buf.length, address, port);socket.send(packet);/ 发送数据报catch(IOException e)e.printStackTrace();socket.close(); / 关闭连接2）UDP时钟校对客户端程序import java.io.*;import .*;import java.util.*;import java.awt.*;import java.awt.event.*public class DatagramClient extends FrameLabel showTime,l1;TextField serverName;Button b1;Boolean showSwitch;Panel p1;String hostName;Font myFont = new Font(Dialog, Font.BOLD, 24);public static void main(String args)DatagramClient dc = new DatagramClient();public DatagramClient()super(时钟客户段);setFont(myFont);setLayout(new BorderLayout();serverName = new TextField(localhost);b1 = new Button(连接);l1 = new Label(服务器名称);showTime = new Label();showSwitch = true;p1 = new Panel();p1.add(l1);p1.add(serverName);add(p1,BorderLayout.NORTH);add(showTime,BorderLayout.CENTER);add(b1,BorderLayout.SOUTH);b1.addActionListener(new Listener();serverName.addActionListener(new Listener();pack();show();class Listener implements ActionListenerpublic void actionPerformed(ActionEvent e)if(e.getSource() = serverName) /连接制定的服务器hostName = serverName.getText();else if(e.getSource() = b1) /改变接受服务器时间的BOOL开关hostName = serverName.getText();if(showSwitch = false)showSwitch = true;b1.setLabel(断开);elseshowSwitch = false;b1.setLabel(连接);showTime();public void showTime()DatagramSocket socket;InetAddress address;DatagramPacket packet;String received;byte buf = new byte256;trysocket = new DatagramSocket();address = InetAddress.getByName(hostName);/将字符串转换为字节数组buf = UDP client Data Transfer.getBytes();packet = new DatagramPacket(buf, buf.length, address, 1080);socket.send(packet);packet = new DatagramPacket(buf, buf.length);socket.receive(packet);received = new String(packet.getData(), 0);showTime.setText(received);socket.close();catch(Exception e) 文件读写1. import java.io.*;2. class fileInfo 3. public static void main(String args) throws IOException 4. File fileToCheck;5. if(args.length0)6. for(int i=0;iargs.length;i+)7. fileToCheck=new File(argsi);8. info(fileToCheck);9. 10. else11. System.out.println(命令行未给出文件！);12. 13. 14. public static void info(File f) throws IOException使用文件类File可以获取文件的各种信息15. File f=new File(“datatemp.dat”);16. f.getName()：返回文件名 temp.dat17. f.getParent()：返回文件所在目录名 data18. f.getPath()：返回文件路径 datatemp.dat19. f.getAbsolutePath()：返回绝对路径 datatemp.dat20. f.exists()：文件是否存在21. f.canWrite(), f.canRead()：文件是否可写、读22. f.isFile(), f.isDirectory()：是否为文件或目录23. f.lastModified(), f.length(), f.delete()：24. 文件的最后修改日期、长度；删除文件25. f.mkdir(), f.list()：创建一个目录；列出目录下所有的文件在生成一个随机文件对象时，除了指明文件对象和文件名之外，还需要指明访问文件的模式。File f = new File(“file.txt”);new RandomAccessFile(f, “r”);new RandomAccessFile(f, “rw”);new RandomAccessFile(“file1.txt”, “r”);new RandomAccessFile(“file2.txt”, “rw”);1. import java.io.*;2. public class randomfile 3. 4. public static void main(String args)5. 6. int data_arr=12,31,56,23,27,1,43,65,4,99;7. try8. RandomAccessFile randf=new RandomAccessFile(“temp.dat“, “RW“);9. for (int i=0;i=0;i-)12. randf.seek(i*4);13. System.out.println(randf.readInt();14. 15. randf.close();16. catch (IOException e)17. System.out.println(“File access error: “+e); 多线程TCP多线程通信import java.io.*;import .*;import java.util.*;SuppressWarnings(value=deprecation,unchecked)public class MultiServer extends ThreadServerSocket serverSocket = null;boolean listening = true;int port = 1080;int count;public MultiServer()tryserverSocket = new ServerSocket(port);System.out.println(The Chat Server is listening on + port);catch(IOException e)System.err.println(Cant listen on Port);System.exit(1);count = 0;while(listening)try/new ClientServiceThread(clients, clientSocket).start();new ClientServiceThread(serverSocket.accept().start();count += 1;System.out.println(The Chat Server get + count + Clients);catch(IOException e)System.err.println(Cant Accept the Client Connection Apply);tryserverSocket.close();catch(IOException e)System.exit(1);this.start();public static void main(String args)MultiServer ms = new MultiServer();class ClientServiceThread extends Threadprivate String name = Client;private Socket socket = null;private Vector clients = null;public ClientServiceThread(Socket socket)super(ClientServiceThread);this.socket = socket;public ClientServiceThread(Vector clients, Socket socket)super(ClientServiceThread);this.socket = socket;this.clients = clients;public void run()tryDataInputStream in = new DataInputStream(new BufferedInputStream(socket.getInputStream();PrintStream out = new PrintStream(new BufferedOutputStream(socket.getOutputStream(), 1024), true);String inputLine, outputLine;GreetingProtocol greeting = new GreetingProtocol();outputLine = cessInput(null);out.println(Welcome to My Chat Server,Please REG your Name, Format: name = yourname);out.flush();while(inputLine = in.readLine() != null)System.out.println( + Say: + inputLine);if(inputLine.startsWith(name) = inputLine.substring(inputLine.indexOf(=) + 1);out.println(Your Name + + is REG);out.flush();elseoutputLine = cessInput(inputLine);out.println(outputLine);out.flush();if(inputLine.equals(bye) break;out.close();in.close();socket.close();catch(IOException e)e.printStackTrace();举例，要进行一组数 1至 30 的累计，分为 3 个线程，每个线程都是从该集合中取 10 个数，分别累加，最后将这些线程的和再加在一起。如代码 4-5 所示。class Sum /共享资源，计数器 count private int count;/共享资源 synchronized public int add() count = count + 1; return count; class SumThread implements Runnable/定义线程 private Sum sd;private int sum = 0; private String name = null; public SumThread(String name, S = name; this.sd = sd; public void run()/必需的重写 try for(int i=0;i10;i+) sum += sd.add(); Thread.sleep(100) Thread.sleep(1000);catch(Exception e) System.out.println(name + 累加和: + sum); public int getSum() return sum; class SumDemo public static void main(String args) throws Exception Thread t = Thread.currentThread();/获得当前主线程 Sum sd = new Sum();/代表共享资源的变量 SumThread st1 = new SumThread(线程 1,sd); /创建子线程 SumThread st2 = n