写出正则表达式，从一个字符串中提取链接地址

public class Regex {

public static void main(String[] args) {
url();
}

static void url() {

String input = “黑马程序员 “;
Pattern pattern;
Matcher matcher;
pattern = Pattern.compile(“<a(?: [^>]*)+href=([^ >]*)(?: [^>]*)*>”);
matcher = pattern.matcher(input);
while (matcher.find()) {
System.out.println(matcher.group());
}
}

}