Find String that contains a given substring ignoring case

[Udaya Wijenayake]

How to find a string that contains given substring ignoring case?
I have used following code. But it considers the case.

 file.getName().contains("abc")   

[Vinoth Kumar Kannan]

A possible option would be, to first convert your base String to lowercase(or uppercase) and then use substring on it.

[Udaya Wijenayake]

Thanks vinoth, I got it

[Seetharaman Venkatasamy]

String str = "javaranch";   
Pattern myPattern = Pattern.compile("ran",Pattern.CASE_INSENSITIVE);
Matcher matcher = myPattern.matcher(str);
System.out.println(matcher.find());

[Darryl Burke]

Using regex is overkill for such a simple requirement.

file.getName().toUpperCase().contains("abc".toUpperCase())

[Seetharaman Venkatasamy]

Darryl Burke wrote:Using regex is overkill for such a simple requirement.

file.getName().toUpperCase().contains("abc".toUpperCase())

but it is flexible . what could you do if the string needs to be lowercase? you need to apply one more condition right?

[David Newton]

But that isn't the requirement. Using a regex *is* overkill for the requirement as stated.

[Rob Spoor]

But calling toUpperCase() on a large String (several thousands characters) may have a negative impact on memory usage. This is one of those cases where you must make a trade off between better speed (toUpperCase(), contains()) and less memory (Pattern). If this operation is needed many times reusing a Pattern object may even be better.

[David Newton]

Meh--if the file name has thousands of characters I'd suggest there's a different problem waiting in the wings.