Java URL 计数器不起作用 [英] Java URL counter is not working

问题描述

我正在尝试计算任何给定 Java 字符串中的 URL 数量:

I'm trying to count the number of URLs in any given Java string:

String test = "Hello World!";
String urlRegex = "<\\b(https?|ftp|file)://[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]>";
pattern = Pattern.compile(urlRegex);
matcher = pattern.matcher(test);
numUrls = matcher.groupCount();
System.err.println("numUrls = " + numUrls);

我很惊讶地看到 numUrls 不是零.关于为什么的任何想法?提前致谢！

I am surprised to see that numUrls is not zero. Any ideas as to why? Thanks in advance!

推荐答案

来自 Matcher#groupCount()

返回此匹配器模式中捕获组的数量.

Returns the number of capturing groups in this matcher's pattern.

你的模式有一组 ...(https?|ftp|file)... 所以它返回 1.

Your pattern has one group ...(https?|ftp|file)... so it returns 1.

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