Converting a char to uppercase in Java

You can use Character#toUpperCase() for this.

char fUpper = Character.toUpperCase(f);
char lUpper = Character.toUpperCase(l);

It has however some limitations since the world is aware of many more characters than can ever fit in 16bit char range. See also the following excerpt of the javadoc:

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toUpperCase(int) method.