JAVA程序员培训定制课程.ppt

第十五章 网络编程 2 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 3 URL URL UniformResourceLocator 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 4 URL类 常用构造方法publicURL Stringspec URLu1 newURL URLu2 newURL u1 welcome html publicURL Stringprotocol Stringhost Stringfile URLu3 newURL http developers index html publicURL Stringprotocol Stringhost intport Stringfile URLu4 newURL http 80 developers index html 5 URL类应用举例 1 importjava io publicclassURLReader publicstaticvoidmain Stringargs try URLtirc newURL BufferedReaderin newBufferedReader newInputStreamReader tirc openStream Strings while s in readLine null System out println s in close catch MalformedURLExceptione System out println e catch IOExceptione System out println e 6 URL类应用举例 2 程序URLReader java输出结果 清华大学网站首页 7 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 Portnumber 8 Socket通信模型 Server ServerSockets port s accept 等待连接 Socket OutputStream InputStream socket close Client Socket host port Attempttoconnect OutputStream InputStream socket close 9 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 10 创建socket Socket ServerSocket类的构造方法Socket InetAddressaddress intport Socket InetAddressaddress intport booleanstream Socket Stringhost intport Socket Stringhost intport booleanstream ServerSocket intport ServerSocket intport intcount 11 客户端Socket的建立try Socketsocket newSocket 127 0 0 1 2000 catch IOExceptione System out println Error e 12 服务器端Socket的建立ServerSocketserver null try server newServerSocket 2000 catch IOExceptione System out println cannotlistento e Socketsocket null try socket server accept catch IOExceptione System out println Error e 13 打开输入 出流PrintStreamos newPrintStream newBufferedOutputStream socket getOutputStream DataInputStreamis newDataInputStream socket getInputStream 关闭Socketos close is close socket close 14 简单的client server程序 importjava io publicclassTestServer publicstaticvoidmain Stringargs ServerSockets null try s newServerSocket 8888 catch IOExceptione while true try Sockets1 s accept OutputStreamos s1 getOutputStream DataOutputStreamdos newDataOutputStream os dos writeUTF Hello bye bye dos close s1 close catch IOExceptione 15 简单的client server程序 importjava io publicclassTestClient publicstaticvoidmain Stringargs try Sockets1 newSocket 127 0 0 1 8888 InputStreamis s1 getInputStream DataInputStreamdis newDataInputStream is System out println dis readUTF dis close s1 close catch ConnectExceptionconnExc System err println 服务器连接失败 catch IOExceptione 16 Ex1 分析并运行M15 14 15页的client server程序 体会Socket编程原理及其实现机制