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Regex to match a fixed sub string in a String

I am trying to write a regular expression to verify the presence of a specific number in a fixed position in a String.
String: 109300300330066611111111100000000017000656052086116020170111Name 1
Number to find: 111111111 (Staring from position 17)
I have written the following regular expression:
^.{16}(?<Ones>111111111)(.*)
My understanding is:
Let first 16 characters be whatever they are
Use the Named Capturing Group to grab the specific word
Let the rest of the characters be whatever they are
I am new to regex, is there any issue with the above approach?
Can it be done in other/better way?
I am using Java 8.

Without more details of why you're doing what you're doing, there's just one possible improvement I can see. You repeated any character 16 times at the beginning of the string rather than writing out 16 .s, which is nice and readable, but then, it would be nice to do the same for the repeated 1s:
^.{16}(?<Ones>1{9})(.*)
Otherwise, the string of 1s is hard to understand without the coder manually counting how many there are in the regex.

If you want to hard-code the ones and you know the starting position and you just wnat to know if it is there, using a regex seems unnecessary. you can use this:
String s = "109300300330066611111111100000000017000656052086116020170111Name 1";
if (s.indexOf("111111111").equals(16) doSomething();
Another possible solution without regex:
if(s.substring(16,25).equals("111111111") doSomething();
Otherwise your regex looks good.

String.split() returns an array with an additional empty value

I'm working on a piece of code where I've to split a string into individual parts. The basic logic flow of my code is, the numbers below on the LHS, i.e 1, 2 and 3 are ids of an object. Once I split them, I'd use these ids, get the respective value and replace the ids in the below String with its respective values. The string that I have is as follow -
String str = "(1+2+3)>100";
I've used the following code for splitting the string -
String[] arraySplit = str.split("\\>|\\<|\\=");
String[] finalArray = arraySplit[0].split("\\(|\\)|\\+|\\-|\\*");
Now the arrays that I get are as such -
arraySplit = [(1+2+3), >100];
finalArray = [, 1, 2, 3];
So, after the string is split, I'd replace the string with the values, i.e the string would now be, (20+45+50)>100 where 20, 45 and 50 are the respective values. (this string would then be used in SpEL to evaluate the formula)
I'm almost there, just that I'm getting an empty element at the first position. Is there a way to not get the empty element in the second array, i.e finalArray? Doing some research on this, I'm guessing it is splitting the string (1+2+3) and taking an empty element as a part of the string.
If this is the thing, then is there any other method apart from String.split() that would give me the same result?
Edit -
Here, (1+2+3)>100 is just an example. The round braces are part of a formula, and the string could also be as ((1+2+3)*(5-2))>100.
Edit 2 -
After splitting this String and doing some code over it, I'm goind to use this string in SpEL. So if there's a better solution by directly using SpEL then also it would be great.
Also, currently I'm using the syntax of the formula as such - (1+2+3) * 4>100 but if there's a way out by changing the formula syntax a bit then that would also be helpful, e.g replacing the formula by - ({#1}+{#2}+{#3}) *
{#4}>100, in this case I'd get the variable using {# as the variable and get the numbers.
I hope this part is clear.
Edit 3 -
Just in case, SpEL is also there in my project although I don't have much idea on it, so if there's a better solution using SpEL then its more than welcome. The basic logic of the question is written at the starting of the question in bold.

If you take a look at the split(String regex, int limit)(emphasis is mine):
When there is a positive-width match at the beginning of this string then an empty leading substring is included at the beginning of the resulting array.
Thus, you can specify 0 as limit param:
If n is zero then the pattern will be applied as many times as possible, the array can have any length, and trailing empty strings will be discarded.

If you keep things really simple, you may be able to get away with using a combination of regular expressions and string operations like split and replace.
However, it looks to me like you'd be better off writing a simple parser using ANTLR.
Take a look at Parsing an arithmetic expression and building a tree from it in Java and https://theantlrguy.atlassian.net/wiki/display/ANTLR3/Five+minute+introduction+to+ANTLR+3
Edit: I haven't used ANTLR in a while - it's now up to version 4, and there may be some significant differences, so make sure that you check the documentation for that version.

Regex to extract value from link

I have a String like file:///android_asset/GwyXUyisyq. I want to extract the GwyXUyisyq from the rest of the string. The value will change in every instance, but the file:///android_asset/ will always remain fixed. What regex can I use to achieve the same?

You don't need a regex here :
Just find the last index of / and replace everything before it :)
String s = "file:///android_asset/GwyXUyisyq";
System.out.println(s.replace(s.substring(0,s.lastIndexOf("/")+1), ""));
O/P :GwyXUyisyq

Regular expression to retreieve integer

Hi I have an URL like "/yyyyyy/xm", where x can be an integer denoting the number of minutes. I need to parse and get this value. Any idea of how this can be using regex or String.split() method? The pattern of the URL is always the same like for example:
/magnetic/20m should give me the value 20
/temperature/500m should give me the value 500
Thanks in advance!

The following should work:
/.*?/(\d+)
You just need to access to the 1st group of the match, and you'll get the numbers there.
Edit:
In the future, finding the regex by yourself. That's a pretty straightforward regex question.

And if you don't like regexp...
String txt = "/magnetic/20m";
String[] components = txt.split("/");
String lastComponent = components[components.length - 1];
int result = Integer.parseInt(lastComponent.replace("m", ""));

How to get last few characters of varying length from a string ..?

I have a multiple string urls, from which i have to pick last few characters, which are id's infact. But the problem is that, the length of id's is not consistent, i.e., if one id is of length 6 then, other may be of length 5 or 4 and so on. The sample urls are like:
www.abc.com/xyz-123456
www.abc.com/pqr-5432
www.abc.com/lmn/opqr-25647
it could have been a lot easier if the length of the particular id portion would have been same, i could have used:
String abc = "www.abc.com/xyz-123456";
String id = abc.substring(abc.length()-6);
But now the scenario is different as length of id portion in the selected url is not the same always, How can i cater this varying id..???? please any help is appreciated.

There is a lastIndexOf method on the String object that will let you find the position of the '-' (I take it that is your separator). From there you can do the substring.

You can use something like this.
String id=abc.subString(abc.lastIndexOf('\'),abc.length()-1);
Hope it will help you. :)

String url1 = "www.abc.com/xyz-123456";
String[] url1Split = url1.split("-");
What you're looking for can be found in url1split[1]

Use regex to remove all characters upto -.
String id = url.replaceAll("^.*-","");
or
String id = url.replaceAll("^.*-(\\w+)$","$1");

You can use LastIndexOf or create the regular expression.