再学习正则表达式之后，可以利用正则表达式进行网络爬虫

首先利用网络编程把网页加载到内存，并且保存到本地

利用正则抽取有用的信息。最终打印输出到控制台

爬取网易首页的所有连接

public class SpiderTest {    public static String getUrlContent(String toUrl){        BufferedReader br =null;        StringBuilder sb = new StringBuilder();        try {            URL url = new URL(toUrl);            try {                br = new BufferedReader(new InputStreamReader(url.openStream()));                String temp = "";                while((temp= br.readLine())!=null){                    sb.append(temp);                }            } catch (IOException e) {                e.printStackTrace();            }        } catch (MalformedURLException e) {            e.printStackTrace();        }        return sb.toString();    }    public static void main(String[] args) {        String str = getUrlContent("https://www.163.com");        //Pattern p = Pattern.compile("
     
      ");//取得超链接的所有内容        Pattern p2 = Pattern.compile("href=\".+?\"");        //Pattern p2 = Pattern.compile("href=\"(.+?)\"");        Matcher m = p2.matcher(str);        while(m.find()){            System.out.println(m.group());            //System.out.println(m.group(1));        }    }}
     

结果显示：

href="https://ent.163.com/19/0628/07/EIOA5VR000038FO9.html"href="https://ent.163.com/19/0628/07/EIO7VG3U00038FO9.html"href="http://fashion.163.com/"href="http://lady.163.com/photoview/00A70026/115916.html#p=EIOGR4FS00A70026NOS"href="http://lady.163.com/photoview/00A70026/115915.html#p=EIOGI7DD00A70026NOS"href="http://dy.163.com/"href="http://dy.163.com/v2/article/detail/EINGAP5J05259Q0E.html"后面还有很多。。。。