转自：https://www.cnblogs.com/akiradunn/p/5855073.html

1 import java.io.BufferedReader;  2   3 import java.io.FileInputStream;  4   5 import java.io.FileNotFoundException;  6   7 import java.io.FileOutputStream;  8   9 import java.io.IOException; 10  11 import java.io.InputStreamReader; 12  13 import java.net.HttpURLConnection; 14  15 import java.net.MalformedURLException; 16  17 import java.net.URL; 18  19 import java.util.regex.Matcher; 20  21 import java.util.regex.Pattern; 22  23 //正则表达式抓取网页数据 24  25 public class HtmlAddressCatch { 26  27  28 public static void main(String[] args) { 29  30   String webaddress = "https://www.zhihu.com/people/Akira_Dunn"; 31   HtmlAddressCatch.getWebTextContent(webaddress); 32   /*String localaddress = "D:\\test\\test.html"; 33   String targetaddress = "D:\\test\\http.txt"; 34   HtmlAddressCatch.getLocalTextContent(localaddress , targetaddress);*/ 35      36 } 37  38 //给定http链接抓取地址 39  40 public static void getWebTextContent(String webaddress){ 41  42 try { 43  44 URL url = new URL(webaddress); 45  46 HttpURLConnection con = (HttpURLConnection)url.openConnection(); 47  48 FileOutputStream file = new FileOutputStream("D:\text.txt"); 49  50 InputStreamReader read = new InputStreamReader(con.getInputStream());//使用InputStreamReader是为了将InputStream字节流转换成为字符流，一次读取更多的字节 51  52 BufferedReader packetreader = new BufferedReader(read);//使用BufferedReader是为了在InputStreamReader的基础上一次读取更多的字节 53  54 int i=0; 55  56 String regex = "https?://\w+\.\w+\.\w+"; 57  58 Pattern p = Pattern.compile(regex); 59  60 while((i=packetreader.read())!=-1) 61  62 { 63  64 String str = packetreader.readLine(); 65  66 Matcher m = p.matcher(str); 67  68 while(m.find()) 69  70 { 71  72 file.write((m.group()+"\r\n").getBytes()); 73  74 } 75  76 } 77  78 } catch (MalformedURLException e) { 79  80 // TODO Auto-generated catch block 81  82 e.printStackTrace(); 83  84 } catch (FileNotFoundException e) { 85  86 // TODO Auto-generated catch block 87  88 e.printStackTrace(); 89  90 } catch (IOException e) { 91  92 // TODO Auto-generated catch block 93  94 e.printStackTrace(); 95  96 } 97  98  99 }100 101 102 // 从本地test.html文件抓取http链接和邮箱地址103 104 public static void getLocalTextContent(String localaddress,String targetaddress){105 106 try {107 108 FileInputStream reader = new FileInputStream(localaddress);109 110 FileOutputStream writer = new FileOutputStream(targetaddress);111 112 byte[] buf = new byte[200];113 114 int point = 0;115 116 //String regex = "https?://\w+\.\w+\.\w+";http链接抓取117 118 String regex = "\w+@\w+\.\w+";//邮箱地址抓取119 120 Pattern p = Pattern.compile(regex);121 122 while((point=reader.read(buf))>0)123 124 {125 126 Matcher m = p.matcher(new String(buf));127 128 while(m.find())129 130 {131 132 writer.write((m.group()+"\r\n").getBytes());133 134 }135 136 }137 138 } catch (FileNotFoundException e) {139 140 // TODO Auto-generated catch block141 142 e.printStackTrace();143 144 } catch (IOException e) {145 146 // TODO Auto-generated catch block147 148 e.printStackTrace();149 150 }151 152 }153 154 }