如何写信检查 URL？

Question

A friend of mine requested to write a simple code to check whether a URL ends with asp or not. I am thinking about accepting the URL as string and checking the last tree letters if it's as or not. I just want to check is there any ways to write this code. (of course there are plenty of ways but it need to be simple)

Thanks in advance

Answer 1

String url = ... 
if(url.endsWith(".asp")){
    // do your thing
}

Answer 2

You will probably want to use the String.endsWith() method.

if (s.endsWith("asp")) {
    System.out.println("Yes");
} else {
    System.out.println("No");
}

If you really want to do this properly, you can parse the string as a real java.net.URL and extract the path using getPath() .

URL url = new URL(s);
String path = url.getPath();
if (path.endsWith("asp")) {
    System.out.println("Yes");
} else {
    System.out.println("No");
}

Answer 3

Use a regular expression:

.*\.asp(x){0,1}(\?){0,1}.*

This will handle these cases:

• http://example.com/index.asp
• http://example.com/index.asp?id=564
• http://example.com/index.aspx
• http://example.com/index.aspx?id=564&id2=333

Answer 4

A regex would be a solution though I find them extremely ugly in Java.

String url = ....
if (Pattern.compile("\.asp[^\.]*\z").matcher(url).matches()){
  //do your thing
}

Yuk indeed. And i'm not sure if I got the regex right