从包含 <img src> 标签的 Java 字符串中提取 url

Extract url from Java String containing <img src> tag

提问by wawanopoulos

I would like to extract the folowing String:

我想提取以下字符串：

http://www.01net.com/images/article/mea/150.100.790233.jpg

This string is the url of the first element tag in the following Java string :

此字符串是以下 Java 字符串中第一个元素标记的 url：

<img src="http://www.01net.com/images/article/mea/150.100.790233.jpg" width="150" height="100" border=0 alt="" align=left style="margin-right:10px;margin-bottom:5px;">A en crtheitroade CNet US, le gouvernement américain aurait cherché à obtenir les master keys de plusieurs acteurs du Web pour pouvtheitroad déchiffrer les communications de leurs utilisateurs, protégées par le protocole SSL.<img width='1' height='1' src='http://rss.feedsportal.com/c/629/f/502199/s/2f34155b/mf.gif' border='0'/><div class='mf-viral'><table border='0'><tr><td valign='middle'><a href="http://share.feedsportal.com/share/twitter/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net" target="_blank"><img src="http://res3.feedsportal.com/social/twitter.png" border="0" /></a> <a href="http://share.feedsportal.com/share/facebook/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net" target="_blank"><img src="http://res3.feedsportal.com/social/facebook.png" border="0" /></a> <a href="http://share.feedsportal.com/share/linkedin/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net" target="_blank"><img src="http://res3.feedsportal.com/social/linkedin.png" border="0" /></a> <a href="http://share.feedsportal.com/share/gplus/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net" target="_blank"><img src="http://res3.feedsportal.com/social/googleplus.png" border="0" /></a> <a href="http://share.feedsportal.com/share/email/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net" target="_blank"><img src="http://res3.feedsportal.com/social/email.png" border="0" /></a></td><td valign='middle'></td></tr></table></div><br/><br/><a href="http://da.feedsportal.com/r/172449334514/u/218/f/502199/c/629/s/2f34155b/kg/342/a2.htm"><img src="http://da.feedsportal.com/r/172449334514/u/218/f/502199/c/629/s/2f34155b/kg/342/a2.img" border="0"/></a><img width="1" height="1" src="http://pi.feedsportal.com/r/172449334514/u/218/f/502199/c/629/s/2f34155b/kg/342/a2t.img" border="0"/>

回答by micha

You can use a regular expressionfor this:

您可以为此使用正则表达式：

    String str = "<img src=\"http://www.01net.com/images/article/mea/150.100.790233.jpg\" width=\"150\" height=\"100\" border=0 alt=\"\" align=left style=\"margin-right:10px;margin-bottom:5px;\">A en crtheitroade CNet US, le gouvernement américain aurait cherché à obtenir les master keys de plusieurs acteurs du Web pour pouvtheitroad déchiffrer les communications de leurs utilisateurs, protégées par le protocole SSL.<img width='1' height='1' src='http://rss.feedsportal.com/c/629/f/502199/s/2f34155b/mf.gif' border='0'/><div class='mf-viral'><table border='0'><tr><td valign='middle'><a href=\"http://share.feedsportal.com/share/twitter/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net\" target=\"_blank\"><img src=\"http://res3.feedsportal.com/social/twitter.png\" border=\"0\" /></a> <a href=\"http://share.feedsportal.com/share/facebook/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net\" target=\"_blank\"><img src=\"http://res3.feedsportal.com/social/facebook.png\" border=\"0\" /></a> <a href=\"http://share.feedsportal.com/share/linkedin/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net\" target=\"_blank\"><img src=\"http://res3.feedsportal.com/social/linkedin.png\" border=\"0\" /></a> <a href=\"http://share.feedsportal.com/share/gplus/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net\" target=\"_blank\"><img src=\"http://res3.feedsportal.com/social/googleplus.png\" border=\"0\" /></a> <a href=\"http://share.feedsportal.com/share/email/?u=http%3A%2F%2Fwww.01net.com%2Feditorial%2F600625%2Fchiffrement-sur-le-web-fbi-et-nsa-voulaient-obtenir-les-cles-ssl-de-geants-du-net%2F%23%3Fxtor%3DRSS-16&t=Chiffrement+sur+le+Web%2C+FBI+et+NSA+voulaient+obtenir+les+cl%C3%A9s+SSL+de+g%C3%A9ants+du+Net\" target=\"_blank\"><img src=\"http://res3.feedsportal.com/social/email.png\" border=\"0\" /></a></td><td valign='middle'></td></tr></table></div><br/><br/><a href=\"http://da.feedsportal.com/r/172449334514/u/218/f/502199/c/629/s/2f34155b/kg/342/a2.htm\"><img src=\"http://da.feedsportal.com/r/172449334514/u/218/f/502199/c/629/s/2f34155b/kg/342/a2.img\" border=\"0\"/></a><img width=\"1\" height=\"1\" src=\"http://pi.feedsportal.com/r/172449334514/u/218/f/502199/c/629/s/2f34155b/kg/342/a2t.img\" border=\"0\"/>";
    Pattern p = Pattern.compile("src=\"(.*?)\"");
    Matcher m = p.matcher(str);
    if (m.find()) {
        System.out.println(m.group(1)); // prints http://www.01net.com/images/article/mea/150.100.790233.jpg
    }

回答by bluewhile

Instead of wasting ressources with Patterns, simply use this:
How it works:

不要用模式浪费资源，只需使用这个：
它是如何工作的：

1. allis the whole text you want to search for
2. sis the start pattern to look for, in this case it will be the first
3. ixis the position of the URL in all

4. the last line gets the String from allstarting at ixto the next "it finds

   String all = "<img src=\"http://www.01net.com/images/article/mea/150.100.790233.jpg\""; // shortened it 
   String s = "<img src=\"";
   int ix = all.indexOf(s)+s.length();
   System.out.println(all.substring(ix, all.indexOf("\"", ix+1)));
   

1. all是您要搜索的整个文本
2. s是要查找的开始模式，在这种情况下它将是第一个
3. ix是 URL 在其中的位置 all

4. 最后一行获取字符串从all开始ix到"它找到的下一个

   String all = "<img src=\"http://www.01net.com/images/article/mea/150.100.790233.jpg\""; // shortened it 
   String s = "<img src=\"";
   int ix = all.indexOf(s)+s.length();
   System.out.println(all.substring(ix, all.indexOf("\"", ix+1)));