网络相关API

InetAddress

// 获取本机的InetAddress实例 InetAddress address = InetAddress.getLocalHost(); System.out.println("计算机名：" + address.getHostName()); System.out.println("IP地址：" + address.getHostAddress()); byte[] bytes = address.getAddress(); // 获取字节数组形式的IP地址 System.out.println("字节数组形式的IP：" + Arrays.toString(bytes)); System.out.println(address); // 直接输出InetAddress对象 // 根据机器名获取InetAddress实例 // InetAddress address2 = InetAddress.getByName("DESKTOP-3IJJFP3"); InetAddress address2 = InetAddress.getByName("110.64.91.161"); System.out.println("计算机名：" + address2.getHostName()); System.out.println("IP地址：" + address2.getHostAddress()); URL常用方法

// 创建一个URL实例 URL imooc = new URL("http://www.imooc.com"); // ?后面表示参数，#后面表示锚点 URL url = new URL(imooc, "/index.html?username=tom#test"); System.out.println("协议：" + url.getProtocol()); System.out.println("主机：" + url.getHost()); // 如果未指定端口号，则使用默认的端口号,此时getPort()方法返回值为-1 System.out.println("端口：" + url.getPort()); System.out.println("文件路径：" + url.getPath()); System.out.println("文件名：" + url.getFile()); System.out.println("相对路径：" + url.getRef()); System.out.println("查询字符串：" + url.getQuery()); 使用URL读取页面内容

// 创建一个URL实例 URL url = new URL("http://www.baidu.com"); // 通过URL的oepnStream方法获取URL对象所表示的资源的字节 InputStream is = url.openStream(); // 将字节输入流转换为字符输入流 InputStreamReader isr = new InputStreamReader(is, "utf-8"); // 为字符输入流添加缓冲 BufferedReader br = new BufferedReader(isr); String data = br.readLine(); // 循环读取数据 while (data != null) { System.out.println(data); // 输出数据 data = br.readLine(); } br.close(); isr.close(); is.close();