All expressions must implement the equals() and
hashCode() methods so that two expressions can be compared
for equality. They are redefined abstract in this class to force their
implementation in subclasses.
All expressions must also be Serializable so that they
can be saved and restored.
Expressions are also designed to be immutable so
that only one instance needs to be created for any given expression
String / FunctionMapper . This allows a container to pre-create
expressions and not have to re-parse them each time they are evaluated.
All expressions must implement the
equals()andhashCode()methods so that two expressions can be compared for equality. They are redefined abstract in this class to force their implementation in subclasses.All expressions must also be
Serializableso that they can be saved and restored.Expressions are also designed to be immutable so that only one instance needs to be created for any given expression String / FunctionMapper . This allows a container to pre-create expressions and not have to re-parse them each time they are evaluated.