08_正则表达式
4/29/2021 java-basic
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# 推荐阅读
# 常见用法
# 1.获取网站域名
（1）工具类
public class DomainHelper {
public static final String REG_DOMAIN_FULL = "(?<=//)(.*?)((?=/)|(?=$))";
public static String getFullDomain(String url) {
return getDomain(url, REG_DOMAIN_FULL);
}
public static String getTopDomain(String url) {
String fullDomain = getDomain(url, REG_DOMAIN_FULL);
String[] split = fullDomain.split("\\.");
String topDomain = null;
if(split.length >= 2){
topDomain = split[split.length-2] + "."+split[split.length-1];
}else{
topDomain = fullDomain;
}
return topDomain;
}
public static String getDomain(String url, String reg) {
Pattern p = Pattern.compile(reg);
Matcher m = p.matcher(url);
String domain = null;
while (m.find()) {
domain = m.group();
}
return domain;
}
}
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（2）测试用例
@Test
public void getDoamin() {
String url1 = "https://tool.oschina.net/uploads/apidocs/jquery/regexp.html";
String fullDomain1 = DomainHelper.getFullDomain(url1);
String topDomain1 = DomainHelper.getTopDomain(url1);
System.out.println("fullDomain1: "+fullDomain1);
System.out.println("topDomain1: "+topDomain1);
String url2 = "http://localhost:8080/";
String fullDomain2 = DomainHelper.getFullDomain(url2);
String topDomain2 = DomainHelper.getTopDomain(url2);
System.out.println("fullDomain2: "+fullDomain2);
System.out.println("topDomai2n: "+topDomain2);
}
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输出：
fullDomain1: tool.oschina.net
topDomain1: oschina.net
fullDomain2: localhost:8080
topDomai2n: localhost:8080
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