java: replace string in url between last 2 slashes /

Question

i have a url like: http://example.com:8080/files/username/oldpassword/12351.png

i need to replace oldpassword with: new password.

oldpassword is not fixed string, it's unknown string.

currently i use this code:

String url = "http://example.com:8080/files/username/oldpassword/12351.png";
String[] split = url.split("/");
String oldPass = split[5];
String newPass = "anyNewRandomPassword";
if( !oldPass.equals(newPass)) {
     url = url.replace(oldPass, newPass);
}

i think it can be done using regex.

any help s much appreciated.

Possible duplicate of [Regex to display a string from the second last occurence of a character](https://stackoverflow.com/questions/22905256/regex-to-display-a-string-from-the-second-last-occurence-of-a-character) — Nicholas K, Oct 28 '18 at 13:57

score 2 · Answer 1 · answered Oct 28 '18 at 18:11

2

Using regex

String out = url.replaceFirst("(.*/)(.*)(/[^/]*)", "$1" + newPass + "$3");
url = out;

answered Oct 28 '18 at 18:11

Joakim Danielson

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how can extract password form this link? String url = "http://example.com:8080/files/username/oldpassword/12351.png"; – Mohammed Ahmed Nov 05 '18 at 10:53
and sometimes the link String url = "http://example.com:8080/username/oldpassword/12351.png"; it has the username after the domain. – Mohammed Ahmed Nov 05 '18 at 10:53
@MohammedAhmed, it works fine for me to replace the old password with the code in my answer for your two new examples as well. – Joakim Danielson Nov 05 '18 at 14:17

Lennart Blom · Answer 2 · 2018-10-28T17:48:59.383

I think the AntPathMatcher is pretty handy for this kind of task and created a Scratch file for you. Hope this helps!

import org.springframework.util.AntPathMatcher;

import java.util.Map;

class Scratch {
    public static void main(String[] args) {
        final String givenUrl = "http://example.com:8080/files/username/oldpassword/12351.png\"";

        AntPathMatcher antPathMatcher = new AntPathMatcher();

        System.out.println("Analyse url '" + givenUrl + "'");
        Map<String, String> stringStringMap = antPathMatcher.extractUriTemplateVariables("**/{username}/{password}/**.**", givenUrl);

        String username = stringStringMap.get("username");
        String oldPassword = stringStringMap.get("password");
        System.out.println("username '" + username + "' + oldPassword '" + oldPassword + "'");

        String newPassword = "myNewSuperSecurePassword";
        System.out.println("Replacing it with new password '" + newPassword + ' ');

        String resultUrl = "";
        if(!newPassword.equals(oldPassword)){
            System.out.println("PASSWORD REPLACEMENT: New Password != old password and will be replaced");
            resultUrl = givenUrl.replace(oldPassword, newPassword);
        }else {
            System.out.println("NO REPLACEMENT: New Password equals old password");
            resultUrl = givenUrl;
        }

        System.out.println("Result URL '" + resultUrl + "'");
    }
}

some times the String url = "http://example.com:8080/username/oldpassword/12351.png"; and String url = "http://example.com:8080/username/oldpassword/12351"; how can i extract the password? — Mohammed Ahmed, Nov 05 '18 at 10:55
Try this new call with a modified pattern: `antPathMatcher.extractUriTemplateVariables("**/{username}/{password}/*", givenUrl);` This works for me! :) — Lennart Blom, Nov 05 '18 at 13:59
i used: String url = "http://example.com:8080/files/user1/password123/12351.png"; String[] split = url.split("/"); System.out.println(split[split.length - 2]); — Mohammed Ahmed, Nov 15 '18 at 23:13

java: replace string in url between last 2 slashes /

2 Answers2