JAVA程序设计：第15章 网络编程

1、第十五章网络编程 本章内容使用包中的类在程序中实现网络通信URL类及其用法Socket通信URLURL(Uniform Resource Locator)-统一资源定位器，表示Internet上某一资源的地址。URL组成: 协议名和资源名protocol:resourceNameURL举例:/http:/home/welcome.htmlhttp:/developers/.URL类常用构造方法public URL(String spec);URL u1 = new URL(“/home/”);public URL(URL context, String spec);URL u2 = new U

2、RL(u1, “welcome.html”);public URL(String protocol, String host, String file); URL u3 = new URL(“http”, “”, “developers/index.html” );public URL (String protocol, String host, int port, String file);URL u4 = new URL(“http”, “”, 80, “developers/index.html” );URL类应用举例(1)import java.io.*;import .*;publi

3、c class URLReaderpublic static void main(String args)tryURL tirc = new URL(/);BufferedReader in = new BufferedReader(new InputStreamReader(tirc.openStream();String s;while(s = in.readLine()!=null)System.out.println(s);in.close();catch(MalformedURLException e) System.out.println(e);catch(IOException

4、e)System.out.println(e); URL类应用举例(2)程序URLReader.java输出结果:清华大学网站首页Socket两个Java应用程序可通过一个双向的网络通信连接实现数据交换，这个双向链路的一端称为一个socket。socket通常用来实现client-server连接。包中定义的两个类Socket和ServerSocket，分别用来实现双向连接的client和server端建立连接时所需的寻址信息远程计算机的机器名或IP地址试图连接的端口号(Port number)Socket通信模型ServerServerSocket s (port #)s.accept()/

5、等待连接Socket()OutputStreamInputStreamsocket.close()ClientSocket (host, port #)（Attempt to connect）OutputStreamInputStreamsocket.close()网络编程的四个基本步骤创建socket;打开连接到socket的输入/输出流；按照一定的协议对socket进行读/写操作；关闭socket;创建socketSocket/ServerSocket类的构造方法Socket(InetAddress address, int port);Socket(InetAddress address

6、, int port, boolean stream);Socket(String host, int port);Socket(String host, int port, boolean stream);ServerSocket(int port);ServerSocket(int port, int count);客户端Socket的建立try Socket socket=new Socket(”,2000);catch(IOException e) System.out.println(Error:+e);服务器端Socket的建立ServerSocket server=null;tr

7、y server=new ServerSocket(2000);catch(IOException e) System.out.println(can not listen to :+e);Socket socket=null;try socket=server.accept();catch(IOException e) System.out.println(Error:+e);打开输入/出流PrintStream os=new PrintStream(new BufferedOutputStream(socket.getOutputStream();DataInputStream is=ne

8、w DataInputStream(socket.getInputStream();关闭Socketos.close();is.close();socket.close();简单的client/server程序import .*;import java.io.*;public class TestServer public static void main(String args) ServerSocket s = null;try s = new ServerSocket(8888); catch (IOException e) while (true) try Socket s1 = s.

9、accept();OutputStream os = s1.getOutputStream();DataOutputStream dos = new DataOutputStream(os);dos.writeUTF(Hello,bye-bye!);dos.close();s1.close(); catch (IOException e) 简单的client/server程序import .*;import java.io.*;public class TestClient public static void main(String args) try Socket s1 = new Socket(, 8888);InputStream is = s1.getInputStream();DataInputStream dis = new DataInputStream(is);System.out.println(dis.readUTF