java - What is the alternative for String.contains method that is case insensitive?

While reading the line as a string from a file and string.contains("someexamplestring") will return the output of the case sensitive string.

If there is "someExampleString" in line, it's not returning.

How to identify a string in a case-insensitive manner?

Answer

Actually, this is a duplicate of How to check if a String contains another String in a case insensitive manner in Java?

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If you've simpler requirements and are dealing with English letters only, you can follow the below answer.

You should do string.toLowerCase().contains("someExampleString".toLowerCase());.

Read more about public String toLowerCase() from Java SE Documentation.

Also, as hinted by Artur Biesiadowski in the comment section of the question, re-iterating it here :

Regarding all the answers suggesting toLowerCase/toUpperCase - be
careful if you go outside of ASCII space. There are some languages
where going lower to upper and back (or other way around) is not
consistent. Turkish with its dotless 'i' comes to mind : Dotted and
dotless I

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Also, to make it safer, you may use another method toLowerCase(Locale.English) and override the locale to English always. But, the limitation being you are not internationalized any longer.

string.toLowerCase(Locale.English).contains("someExampleString".toLowerCase(Locale.English));