How to extract URLs ending in .com or .cn in Java regular expressions?

Java regular expressions efficiently extract text information

In Java programming, it is often necessary to extract content that conforms to a specific pattern from text. Regular expressions provide an efficient solution for this. This article uses a case to demonstrate how to extract specific information using Java regular expressions.

Problem: Only URLs ending in ".com" or ".cn" are extracted from text that contains multiple URLs.

Solution: Use the regular expression www\.\S*?(com|cn) to match a string that starts with "www." and ends with ".com" or ".cn". www\. .Match "www.", \S*? Match any non-whitespace character (non-greedy mode), (com|cn) matches ".com" or ".cn". The Pattern.CASE_INSENSITIVE flag ensures that the match is case-insensitive.

Java code example:

 String html = " <a>www.baidu.com</a> <a>www.qq.com</a> <a>www.aaa.cn</a> www.eee.cn";
String reg = "www\\.\\S*?(com|cn)";

Pattern pattern = Pattern.compile(reg, Pattern.CASE_INSENSITIVE);
Matcher matcher = pattern.matcher(html);
while (matcher.find()) {
    System.out.println(matcher.group());
}

Output result:

 <code>www.baidu.com www.qq.com www.aaa.cn www.eee.cn</code>

This code demonstrates how to compile regular expressions, use the Matcher class to match, and loop out the matching results. By adjusting regular expressions, text information in different modes can be flexibly extracted to achieve efficient text data processing.

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