org.springframework.expression.spel.ast

Class Operator.DescriptorComparison

java.lang.Object

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

Enclosing class:

Operator

protected static class Operator.DescriptorComparison
extends java.lang.Object

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

Field Summary

Fields

Modifier and Type	Field and Description
(package private) boolean	areCompatible
(package private) boolean	areNumbers
(package private) char	compatibleType
(package private) static Operator.DescriptorComparison	INCOMPATIBLE_NUMBERS
(package private) static Operator.DescriptorComparison	NOT_NUMBERS

Constructor Summary

Constructors

Modifier	Constructor and Description
private	DescriptorComparison(boolean areNumbers, boolean areCompatible, char compatibleType)

Method Summary

Modifier and Type	Method and Description
static Operator.DescriptorComparison	checkNumericCompatibility(java.lang.String leftDeclaredDescriptor, java.lang.String rightDeclaredDescriptor, java.lang.String leftActualDescriptor, java.lang.String rightActualDescriptor) Returns 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

Field Detail

NOT_NUMBERS

static Operator.DescriptorComparison NOT_NUMBERS

INCOMPATIBLE_NUMBERS

static Operator.DescriptorComparison INCOMPATIBLE_NUMBERS

areNumbers

final boolean areNumbers

areCompatible

final boolean areCompatible

compatibleType

final char compatibleType

Constructor Detail

DescriptorComparison

private DescriptorComparison(boolean areNumbers,
                             boolean areCompatible,
                             char compatibleType)

Method Detail

checkNumericCompatibility

public static Operator.DescriptorComparison checkNumericCompatibility(java.lang.String leftDeclaredDescriptor,
                                                                      java.lang.String rightDeclaredDescriptor,
                                                                      java.lang.String leftActualDescriptor,
                                                                      java.lang.String rightActualDescriptor)

Returns 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