1. URL:(Uniform Resource Locator) 统一资源定位符 他标识Internet上某一资源的地址
    2. URL的基本结构由5个部分组成

    传输协议://主机名称:端口号/文件名#片段名?参数列表
    例:https://yazhouse8.com/article.php?cate=1
    片段名: 锚点

    2. /**
    3.  * @author:LYY 创建时间:2022/5/11
    4.  */
    5. public class URLTest {
    8.     /**
    9.      * 下载资源
    10.      * 从指定的url下载资源
    11.      */
    12.     @Test
    13.     void test01() {
    14.         FileOutputStream fileOutputStream = null;
    15.         InputStream inputStream = null;
    16.         HttpURLConnection urlConnection = null;
    17.         try {
    18.             // url对象 相当于在内存中记录的信息
    19.             URL url = new URL("https://i.17173cdn.com/9ih5jd/YWxqaGBf/forum/202204/27/hFMSfNbqbuAcayq.gif");
    20.             // 获取链接对象
    21.             urlConnection = (HttpURLConnection) url.openConnection();
    22.             // 打开链接
    23.             urlConnection.connect();
    24.             // 获取输入流
    25.             inputStream = urlConnection.getInputStream();
    26.             // 获取输出流 将文件保存到本地硬盘
    27.             fileOutputStream = new FileOutputStream("hFMSfNbqbuAcayq.gif");
    28.             byte[] bytes = new byte[1024];
    29.             int len;
    30.             while ((len = inputStream.read(bytes)) != -1) {
    31.                 fileOutputStream.write(bytes, 0, len);
    32.             }
    34.         } catch (MalformedURLException e) {
    35.             e.printStackTrace();
    36.         } catch (IOException e) {
    37.             e.printStackTrace();
    38.         } finally {
    39.             // 释放资源
    40.             if (fileOutputStream != null) {
    41.                 try {
    42.                     fileOutputStream.close();
    43.                 } catch (IOException e) {
    44.                     e.printStackTrace();
    45.                 }
    46.             }
    47.             if (inputStream != null) {
    48.                 try {
    49.                     inputStream.close();
    50.                 } catch (IOException e) {
    51.                     e.printStackTrace();
    52.                 }
    53.             }
    54.             if (urlConnection != null) {
    55.                 urlConnection.disconnect();
    56.             }
    57.         }
    58.     }
    60.     @Test
    61.     void test() {
    62.         try {
    63.             URL url = new URL("https://yazhouse8.com/article.php?cate=1");
    64.             // 输出url协议
    65.             System.out.println(url.getProtocol());
    66.             // 输出url ip
    67.             System.out.println(url.getHost());
    68.             // 输出url 端口号
    69.             System.out.println(url.getPort());
    70.             // 输出文件路径
    71.             System.out.println(url.getPath());
    72.             // 输出url查询条件
    73.             System.out.println(url.getQuery());
    74.             // 输出资源路径
    75.             System.out.println(url.getFile());
    77.         } catch (MalformedURLException e) {
    78.             e.printStackTrace();
    79.         }
    80.     }
    81. }