URL网络编程
1.URL:统一资源定位符，对应着互联网的某一资源地址
2.格式：
http://localhost:8080/examples/beauty.jpg?username=Tom
协议 主机名 端口号 资源地址 参数列表
示例代码01：
public class UrlTest01 { public static void main(String[] args) { try { URL url = new URL("http://localhost:8080/examples/beauty.jpg?username=Tom"); // public String getProtocol( ) 获取该URL的协议名 System.out.println(url.getProtocol()); // public String getHost( ) 获取该URL的主机名 System.out.println(url.getHost()); // public String getPort( ) 获取该URL的端口号 System.out.println(url.getPort()); // public String getPath( ) 获取该URL的文件路径 System.out.println(url.getPath()); // public String getFile( ) 获取该URL的文件名 System.out.println(url.getFile()); // public String getQuery( ) 获取该URL的查询名 System.out.println(url.getQuery()); } catch (MalformedURLException e) { e.printStackTrace(); } } }
运行结果：
示例代码02：
public class UrlTest02 { public static void main(String[] args) throws Exception { HttpURLConnection urlConnection = null; InputStream is = null; FileOutputStream fos = null; try { URL url = new URL("http://localhost:8080/examples/beauty.jpg"); urlConnection = (HttpURLConnection) url.openConnection(); urlConnection.connect(); is = urlConnection.getInputStream(); fos = new FileOutputStream("day10\\beauty3.jpg"); byte[] buffer = new byte[1024]; int len; while((len = is.read(buffer)) != -1){ fos.write(buffer,0,len); } System.out.println("下载完成"); } catch (IOException e) { e.printStackTrace(); } finally { //关闭资源 if(is != null){ try { is.close(); } catch (IOException e) { e.printStackTrace(); } } if(fos != null){ try { fos.close(); } catch (IOException e) { e.printStackTrace(); } } if(urlConnection != null){ urlConnection.disconnect(); } } } }
