You need to look into doing standard IO with java.
please read about them here: Java IO: System.in, System.out, and System.err
I found this bit on SO where it says in one solution that in android System.out and System.err are redirected to /dev/null, effectively sending all your output into nirvana. Please read the details on SO: Is there a way to print to the console in an Android app?
There is also an promising link sending you to this site: http://developer.android.com/tools/help/adb.html#logcat