Editext validation for button click

I have an edittext and when the button is clicked 开发者_如何学编程it allows only Strings.

I do this by using an if statement to show a dialog with this condition: (str.matches("[0-9]*")

but when I enter this ttttt12323 and press the button it allows string and int to go through.

I want to put validation for not allowing string and text together specifically only Strings.

Can this be done. Thanks

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So you want to check if your input consists of characters only, right?

You could try something like (str.matches("[A-Za-z]*")