org.springframework.expression

Interface OperatorOverloader

All Known Implementing Classes:

StandardOperatorOverloader

public interface OperatorOverloader

By default the mathematical operators Operation support simple types like numbers. By providing an implementation of OperatorOverloader, a user of the expression language can support these operations on other types.

Since:

3.0

Author:

Andy Clement

Method Summary

Modifier and Type	Method and Description
Object	operate(Operation operation, Object leftOperand, Object rightOperand) Execute the specified operation on two operands, returning a result.
boolean	overridesOperation(Operation operation, Object leftOperand, Object rightOperand) Return true if the operator overloader supports the specified operation between the two operands and so should be invoked to handle it.

Method Detail

overridesOperation

boolean overridesOperation(Operation operation,
                           @Nullable
                           Object leftOperand,
                           @Nullable
                           Object rightOperand)
                    throws EvaluationException

Return true if the operator overloader supports the specified operation between the two operands and so should be invoked to handle it.

Parameters:

operation - the operation to be performed

leftOperand - the left operand

rightOperand - the right operand

Returns:

true if the OperatorOverloader supports the specified operation between the two operands

Throws:

EvaluationException - if there is a problem performing the operation

operate

Object operate(Operation operation,
               @Nullable
               Object leftOperand,
               @Nullable
               Object rightOperand)
        throws EvaluationException

Execute the specified operation on two operands, returning a result. See Operation for supported operations.

Parameters:

operation - the operation to be performed

leftOperand - the left operand

rightOperand - the right operand

Returns:

the result of performing the operation on the two operands

Throws:

EvaluationException - if there is a problem performing the operation