最近需要把一个url的根域名找出来,看着挺简单的需求,结果写出来的代码 却有bug:
public String getSourceDomain(String sourceLink) { if (sourceLink == null) { return null; } try { URI url = new URI(sourceLink); String host = url.getHost(); int split = host.indexOf('.'); return "www" + host.substring(split, host.length()); } catch (URISyntaxException e) { return null; } }
这段代码的问题在于,如果只能处理movie.douban.com这种情况,如果是douban.com,或者test.movie.douban.com则无法处理,正确的做法
public String getSourceDomain() { if (sourceLink == null) { return null; } try { URI url = new URI(sourceLink); String host = url.getHost(); String[] hostStr = host.split("\\."); int length = hostStr.length; if (hostStr.length >= 2) { return "www." + hostStr[length - 2] + "." + hostStr[length - 1]; } else { return host; } } catch (URISyntaxException e) { return null; } }