PERFORMANCE – String Equals Empty String

Instead of calling .equals() on an empty String we should test the
String for emptiness by comparing it’s .length() to zero (can use
.isEmpty()). This is more efficient 9/10 of the time.
PERFORMANCE – String to Char

Changed MANY single character strings to chars. Although minimal, this
requires less computation.
JAVADOC – Use of <code>

Since JDK1.5 these constructs can be replaced to give additional
functionality.
NullPointerException – Calling .equals() with String Literal Arguments

String literals generally should be the target of .equals(), rather than
argument. This helps minimize NullPointerExceptions. Fixed 394 instances
of this. See
http://www.javacodegeeks.com/2012/06/avoid-null-pointer-exception-in-java.html
for more detail.
FORMATTING - Long ending in ‘l’ instead of ‘L’

Replaced lowercase with uppercase to prevent confusion.