查看“正则表达式练习：解析URL”的源代码

https://www.bilibili.com/video/BV1Eq4y1E79W?p=26

对一个URL进行解析 "<nowiki>https://www.sohu.com:8080/abc/index.html</nowiki>"

* 要求得到协议是什么？ http
* 域名是什么? www.sohu.com
* 端口是什么? 8080
* 文件名是什么? index.htm

=== 自己实现 ===
<syntaxhighlight lang="java">
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Homework03 {

    public static void main(String[] args) {

        String content = "https://www.sohu.com:8080/abc/index.html";

        String regex = "^(http[s]?)://((\\w+\\.)+\\w+):(\\d+)(/\\w+)+/(\\w+\\.\\w+)$";

        Matcher matcher = Pattern.compile(regex).matcher(content);


        if (matcher.find()) {

            System.out.println(matcher.group(1));

            System.out.println(matcher.group(2));

            System.out.println(matcher.group(4));

            System.out.println(matcher.group(6));

        }

    }

}
</syntaxhighlight><syntaxhighlight lang="console">
https
www.sohu.com
8080
index.html
</syntaxhighlight>





=== 视频实现 ===
<syntaxhighlight lang="java">
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Homework03 {

    public static void main(String[] args) {

        String content = "http://www.sohu.com:8080/abc/index.html";

        String regStr = "^([a-zA-Z]+)://([a-zA-Z.]+):(\\d+)[\\w-/]*/([\\w.]+)$";

        Pattern pattern = Pattern.compile(regStr);

        Matcher matcher = pattern.matcher(content);

        if (matcher.matches()) { //整体匹配，如果匹配成功，可以通过group(x)，获取对应分组的内容

            System.out.println("整体匹配=" + matcher.group(0));

            System.out.println("协议：" + matcher.group(1));

            System.out.println("域名：" + matcher.group(2));

            System.out.println("端口：" + matcher.group(3));

            System.out.println("文件：" + matcher.group(4));

        } else {

            System.out.println("没有匹配成功");

        }

    }//end main

}
</syntaxhighlight><syntaxhighlight lang="console">
整体匹配=http://www.sohu.com:8080/abc/index.html
协议：http
域名：www.sohu.com
端口：8080
文件：index.html
</syntaxhighlight>