Is java.util.Scanner that slow?

Question

In a Android application I want to use Scanner class to read a list of floats from a text file (it\'s a list of vertex coordinates for OpenGL). Exact code is:

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Answer 1

I got the exactly same problem. It took 10 minutes to read my 18 KB file. In the end I wrote a desktop application that converts those human readable numbers into machine-readable format, using DataOutputStream.

The result was astonishing.

Btw, when I traced it, most of the Scanner method calls involves regular expressions, whose implementation is provided by com.ibm.icu.** packages (IBM ICU project). It's really overkill.

The same goes for String.format. Avoid it in Android!