Android ADT 21.0 warning: Implicitly using the default locale

I've updated ADT to v. 21 and new warning appeared in this code:

if (e.getMessage().toLowerCase().contains("blabla"))

Implicitly using the default locale is a common source of bugs: Use toLowerCase(Locale) instead

So I try:

if (e.getMessage().toLowerCase(Locale.ENGLISH).contains("blabla"))

But error still remained! How fix this?

You should use Locale.getDefault() especially if you cant be sure that your text will always be in english. Also lint errors like that one you are having usually disappear after you run lint again or clean your project.

You simply need to clean your project by clicking:

Build > Clean Project or Build > Rebuild Project

Actually, use Locale.getDefault() when the goal is to present text to the user. However, and this is the whole point of the Lint check, you should probably be using Locale.US whenever the goal is for machine readability/usage. Because it is already implicitly using Locale.getDefault() if you don't specify one, and this can cause hard to find bugs when devices have their own default locale specified. It seems that you also need to clean your project either way, as everyone else has suggested.

use Locale.getDefault() and than clean your project.

It's probably a Lint bug. Just try to cut the whole line of code

if (e.getMessage().toLowerCase(Locale.ENGLISH).contains("blabla"))

save, then paste.

Cleaning the project didn't work for me, so I added the default locale on my code:

String.format(Locale.getDefault(), "firstname: %s, lastname: %s", firstName, lastName));

Depending on your project, you might want to take a look at the Locale explanation.

As written in https://stackoverflow.com/questions/16927664/why-does-android-lint-warn-about-string-format-using-default-locale-when-explici/ and https://stackoverflow.com/questions/10336730/which-locale-should-i-specify-when-i-call-stringtolowercase some languages like Turkish have different rules of case converting (the 'I' and 'i' characters are not case-converted to one another).

I suppose, this is a bug of Lint rules. Setting Locale.getDefault() is a good choice. To remove the warning, add before method:

@SuppressLint("DefaultLocale")