Java language level syntactic sugaring

[spannm]

Non-functional change - make use of new Java language features available up to Java 17 LTS

• Use String.repeat()
• Replace statements with enhanced switch
• Use pattern variable
• Convert to enhanced for-loop
• Prefer StringBuilder over StringBuffer
• Remove unnecessary boxing/unboxing
• Use Objects.equals() rather than equals() expression
• Replace explicit types by diamond operator
• Use lambdas for anonymous types
• Use Comparator combinator
• Introduce method references for lambdas
• Change statement to expression lambdas
• Check for null using method call