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Java 8 Get full URL path without last segment (with or without trailing slash)

I have URLs as below and need to trim them as follows without the last segment. There may or may not be a trailing slash.
localhost:8080/myapp -> localhost:8080/
https://myapp-dev.myhost.com/app/ -> https://myapp-dev.myhost.com/
https://myapp-dev.myhost.com/app/app2 -> https://myapp-dev.myhost.com/app/
Of course I could try solutions like
String[] tokens = uri.split("/"); // then concatenate previous ones...
or
Path path = Paths.get(uri.getPath());
String secondToLast = path.getName(path.getNameCount() - 2).toString();
But isn't there some more robust utility or method?

Try passing the url string into a URL object and then pulling out the required segments:
URL someURL = new URL("https://myapp-dev.myhost.com/app/");
System.out.println("PATH = " + someURL.getPath());
System.out.println("HOST = " + someURL.getHost());
System.out.println("PROTOCOL = " + someURL.getProtocol());
System.out.println("PORT = " + someURL.getPort());
output:
PATH = /app/
HOST = myapp-dev.myhost.com
PROTOCOL = https
PORT = 8080

If all you need is to trim everything after the last "/" (or the second last if the string ends with "/") may be a simple function could solve this:
public static void main(String[] args){
Function<String,String> trimUrlString = s -> {
s = s.endsWith("/") ? s.substring(0, s.length()-1) : s;
return s.substring(0, s.lastIndexOf('/')+1);
};
String u1 = "localhost:8080/myapp";
System.out.println(trimUrlString.apply(u1));
String u2 = "https://myapp-dev.myhost.com/app/";
System.out.println(trimUrlString.apply(u2));
}
//output: localhost:8080/ https://myapp-dev.myhost.com/
EDIT
Another aproach which might be shorter is to chain two replaceAll calls :
myString.replaceAll("/$", "").replaceAll("/[^/]+$", "/");
The first call will remove a forward slash at the end if any, if there is no slash at the end myString remains the same. The second call will then replace every char after the last / which is not a /
Some test cases with your examples:
String[] urls = {"localhost:8080/myapp",
"https://myapp-dev.myhost.com/app/test.pdf",
"http://myapp-dev.host.com/app/",
"http://app.host.com:8080/app/app2"};
for(String url : urls){
String s = url.replaceAll("/$", "").replaceAll("/[^/]+$", "/");
System.out.println(url);
System.out.println(s);
System.out.println();
}

You can split the string using a regular expression as I have mentioned in the comment.
I provide below the Regex.
^https?:\/\/\w+(:[0-9]*)?(\.\w+)?
You can try with the following examples.
https://mydomain:8080
http://localhost:8090
You can also verify in https://rubular.com/ by pasting the regular expression and the example strings.

Use String.lastIndexOf and String.substring to strip off last component.
Something like:
private String stripLastComponent(String path) {
int n = path.lastIndexOf('/');
if(n < 0) { // no / in path
return path;
}
String stripped = path.substring(0, n);
if(n == path.length()) { // '/' was last char, so try stripping again
stripped = stripLastComponent(stripped);
}
return stripped;
}

Get the specific value from the last part of a String in Android

I wanted to get the value from the last part of a String, here's my example String
String str="www.mywebsite.com?id=0001&user=myname"
I like to get the word myname from that String, All examples that I'm seeing is like this
String getUser = str.substring(str.length() - 6);
but user value length changes every transaction so I can't fix that to any value. Can anyone please help me in how I will be able to get the user value from that String. Thanks.

String getUser=str.subString(str.lastIndexOf("=")+1,Str.length());
Will return myname.

If your string is going to be a uri, you can use Uri's getQueryParameter:
String str="www.mywebsite.com?id=0001&user=myname";
Uri uri = Uri.parse(str);
return uri.getQueryParameter("user");

Try this
String getUser = str.substring(str.lastIndexOf("=") + 1);

Try this
String foo = "www.mywebsite.com?id=0001&user=myname";
String[] split = foo.split("=");
String name = split[split.length-1];
with String.split(), you can split strings with a delimiter and put the values in an array. It is similar to PHPs' explode method.

String str="www.mywebsite.com?id=0001&user=myname";
String user = getQueryParamValue(str);
public static final String getQueryParam(String url) {
List<NameValuePair> params = URLEncodedUtils.parse(new URI(url), "UTF-8");
for (NameValuePair param : params){
if("user".equalsIgnoreCase(param.getName())) {
return param.getValue();
}
}
return null;
}

Java : how to get text between "http://" and first following "/" occurence ? And after first "/" occurence?

I am still a novice with regular expressions, "regex", etc... in Java.
If I have an url like this : "http://somedomain.someextention/somefolder/.../someotherfolder/somepage"
What is the simplest way to get :
"somedomain.someextention" ?
"somefolder/.../someotherfolder/somepage" ?
"somepage" ?
Thanks !

You don't have to (and probably shouldn't) use regex here. Instead use classes defined to handle things like this. You can use for example URL, URI, File classes like
String address = "http://somedomain.someextention/somefolder/.../someotherfolder/somepage";
URL url = new URL(address);
File file = new File(url.getPath());
System.out.println(url.getHost());
System.out.println(url.getPath());
System.out.println(file.getName());
Outpit:
somedomain.someextention
/somefolder/.../someotherfolder/somepage
somepage
Now you can need to get rid of / at start of path to your resource. You can use substring(1) here if resource starts with /.
But if you really must use regex you can try with
^https?://([^/]+)/(.*/([^/]+))$
Now
group 1 will contain host name,
group 2 will contain path to resource
group 3 will contain name of resource

The best way to get those components is to use the URI class; e.g.
URI uri = new URI(str);
String domain = uri.getHost();
String path = uri.getPath();
int pos = path.lastIndex("/");
...
// or use File to parse the path string.
You could do it using regexes on the raw url string, but there is a risk that you won't correctly cope with all of the variability that is possible in a URL. (Hint: the regex supplied by #Pchenko doesn't :-)) And you would definitely need to use a decoder to deal with possible percent encoding.

This is not a regexp or URI use but simple substring code as an excersise material. Missing few corner case format validation.
int lastDelim = str.lastIndexOf('/);
if (lastDelim<0) throw new IllegalArgumentException("Invalid url");
int startIdx = str.indexOf("//");
startIdx = startIdx<0 ? 0 : startIdx+2;
int pathDelim = str.indexOf('/', startIdx);
String domain = str.substring(startIdx, pathDelim);
String path = str.substring(pathDelim+1, lastDelim);
String page = str.substring(lastDelim+1);

If you would like to use regex to decode the URL instead of using the URI class, as described in the previous answers, the below link gives a nice tutorial of regex, and it explains decoding a sample URL as well. You could learn it there and try it out.
http://www.beedub.com/book/2nd/regexp.doc.html

It's not regex, or scalable at that, it works though:
public class SomeClass
{
public static void main(String[] args)
{
SomeClass sclass = new SomeClass();
String[] string =
sclass.parseURL("http://somedomain.someextention/somefolder/.../someotherfolder/somepage");
System.out.println(string[0]);
System.out.println(string[1]);
System.out.println(string[2]);
}
private String[] parseURL(String url)
{
String part1 = url.substring("http://".length(), url.indexOf("/", "http://".length()));
String part2 = url.substring("http://".length() + part1.length() + 1, url.lastIndexOf("/"));
String part3 = url = url.substring(url.lastIndexOf("/") + 1);
return new String[] { part1, part2, part3 };
}
}
Output:
somedomain.someextention
somefolder/.../someotherfolder
somepage

String url getting extension

I am trying to get the extension (dk, com, org, eu) or any other domain extension from a String.
for example:
http://www.example.com/siteone/sitetwo/currentpage
From this String i would like to get the .com
I could go the very messy way around and do subString however the problem comes when an url looks like this:
dk.webpage.otherstuff.com/page
So how will i go around this in a way that doesnt require me to check everything every step of the way

Use the getHost() method like this:
public static String getDomainName(String testUrl) throws URISyntaxException {
URI fullUri = new URI(testUrl);
String domainName = fullUri.getHost();
return domainName.startsWith("www.") ? domainName.substring(4) : domainName;
}
After you have done that then just use subString for the .com part of your domain name.

Use Guava's InternetDomainName class. Specifically have a look at the publicSuffix method.

Try this:
String ext = url.replaceAll(".*//[^/]*(\\.\\w+)/.*", "$1");
Some test code:
String url = "http://www.example.com/siteone/sitetwo/currentpage";
String ext = url.replaceAll(".*//[^/]*(\\.\\w+)/.*", "$1");
System.out.println(ext);
Output:
.com

Try this :
private String getExtensionFromDomain(String domainName){
int p = domainName.lastIndexOf(".") +1;
return domainName.substring(p);
}
In case of example.co.ma this will output : .ma

Extracting the file name from the variable dynamically

I have a query a method in which the parameter is coming as a file name that upon debugging I have analyzed, as shown below:
private processfile ( string filePath)
{
}
Now this file path can be like:
C:\abc\file1.txt
or
C:\abc\def\file1.txt
or
C:\ghj\ytr\wer\file1.txt
Now my query is that I have to extract the file name only and have to store in a string parameter. So I have to store the file1.txt in a string, let say in a string parameter s , so finally s will be stored as
String s = file1.txt
How to achieve this?

This should do the trick
String s = new File(filepath).getName()
although I would rename filepath to filePath.
You can find File#getName() documentation here

You can use indexOf and substring for this case:
String s = filepath.substring(filepath.lastIndexOf(File.separator)+1);
File.getName also takes similar approach, see source below:
public String getName() {
int index = path.lastIndexOf(separatorChar);
if (index < prefixLength) return path.substring(prefixLength);
return path.substring(index + 1);
}