使用正则表达式从复杂的字符串中获取项目

Question

I'm new to regex and I am trying to get the string tumblr_nk8j5bEGc01u59obp (dynamic, not static) from below. I don't really know where to begin, could somebody please help me? (Java)

<embed type="application/x-shockwave-flash" src="https://secure.assets.tumblr.com/swf/audio_player.swf?audio_file=https%3A%2F%2Fwww.tumblr.com%2Faudio_file%2F80stmntsoundthingies%2F111871866039%2Ftumblr_nk8j5bEGc01u59obp&color=FFFFFF" height="27" width="207" quality="best" wmode="opaque"></embed>

Answer 1

I agree with Mathemats that I wouldn't use regex for this particular purpose.

I'd do something like the following:

public static String isolateTumblrCodeFromURL(String url) {
    int start = url.indexOf("tumblr_");
    if (start == -1) return null;
    int end = url.indexOf('&', start);
    if (end == -1) return null;
    return url.substring(start, end);
}

Of course, you could use regex too, but this seems simpler and faster.

In addition, this only works if there is only a single instance of the "tumblr_" String that you're looking for. If you need multiple, just wrap that logic in a loop controlled by int start = url.indexOf("tumblr_"); start>=0; start = url.indexOf("tumblr_", start) int start = url.indexOf("tumblr_"); start>=0; start = url.indexOf("tumblr_", start) int start = url.indexOf("tumblr_"); start>=0; start = url.indexOf("tumblr_", start) , and replace the return s with add s to your datastructure of choice.