org.springframework.expression.spel.ast

Class Operator.DescriptorComparison

java.lang.Object

org.springframework.expression.spel.ast.Operator.DescriptorComparison

Enclosing class:

Operator

protected static final class Operator.DescriptorComparison
extends Object

A descriptor comparison encapsulates the result of comparing descriptor for two operands and describes at what level they are compatible.

Method Summary

Modifier and Type	Method and Description
static Operator.DescriptorComparison	checkNumericCompatibility(String leftDeclaredDescriptor, String rightDeclaredDescriptor, String leftActualDescriptor, String rightActualDescriptor) Return an object that indicates whether the input descriptors are compatible.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

checkNumericCompatibility

public static Operator.DescriptorComparison checkNumericCompatibility(@Nullable
                                                                      String leftDeclaredDescriptor,
                                                                      @Nullable
                                                                      String rightDeclaredDescriptor,
                                                                      @Nullable
                                                                      String leftActualDescriptor,
                                                                      @Nullable
                                                                      String rightActualDescriptor)

Return an object that indicates whether the input descriptors are compatible.

A declared descriptor is what could statically be determined (e.g. from looking at the return value of a property accessor method) whilst an actual descriptor is the type of an actual object that was returned, which may differ.

For generic types with unbound type variables, the declared descriptor discovered may be 'Object' but from the actual descriptor it is possible to observe that the objects are really numeric values (e.g. ints).

Parameters:

leftDeclaredDescriptor - the statically determinable left descriptor

rightDeclaredDescriptor - the statically determinable right descriptor

leftActualDescriptor - the dynamic/runtime left object descriptor

rightActualDescriptor - the dynamic/runtime right object descriptor

Returns:

a DescriptorComparison object indicating the type of compatibility, if any