Affects Version/s: None
Fix Version/s: 2.1
The JexlArithmetic class is currently not thread-safe because of the single field:
/** Whether this JexlArithmetic instance behaves in strict or lenient mode. */
protected boolean strict;
If this field were made final, and the setLenient() method removed, then the class would be immutable and therefore thread-safe.
This would mean that JexlEngine would also have to change.
The class is new to 2.0, so this is the best time to fix this.