org.hibernate.validator.internal.util

Class ReflectionHelper

java.lang.Object

org.hibernate.validator.internal.util.ReflectionHelper

public final class ReflectionHelper
extends java.lang.Object

Some reflection utility methods. Where necessary calls will be performed as PrivilegedAction which is necessary for situations where a security manager is in place.

Author:

Hardy Ferentschik, Gunnar Morling, Kevin Pollet <kevin.pollet@serli.com> (C) 2011 SERLI, Guillaume Smet

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String[]	PROPERTY_ACCESSOR_PREFIXES

Method Summary

Modifier and Type	Method and Description
static java.lang.Class<?>	boxedType(java.lang.Class<?> type) Returns the corresponding auto-boxed type if given a primitive type.
static java.lang.reflect.Type	boxedType(java.lang.reflect.Type type) Returns the corresponding auto-boxed type if given a primitive type.
static java.lang.Class<?>	getClassFromType(java.lang.reflect.Type type) Converts the given Type to a Class.
static java.lang.reflect.Type	getCollectionElementType(java.lang.reflect.Type type) Determines the type of the elements of an Iterable, array or the value of a Map.
static java.lang.Object	getIndexedValue(java.lang.Object value, int index) Tries to retrieve the indexed value from the specified object.
static java.lang.Object	getMappedValue(java.lang.Object value, java.lang.Object key) Tries to retrieve the mapped value from the specified object.
static java.lang.String	getPropertyName(java.lang.reflect.Member member) Returns the JavaBeans property name of the given member.
static java.lang.Object	getValue(java.lang.reflect.Field field, java.lang.Object object)
static java.lang.Object	getValue(java.lang.reflect.Method method, java.lang.Object object)
static boolean	isCollection(java.lang.reflect.Type type) Indicates whether the given type represents a collection of elements or not (i.e.
static boolean	isGetterMethod(java.lang.reflect.Executable executable) Checks whether the given executable is a valid JavaBeans getter method, which is the case if its name starts with "get" and it has a return type but no parameter or its name starts with "is", it has no parameter and is returning boolean or its name starts with "has", it has no parameter and is returning boolean (HV-specific, not mandated by JavaBeans spec).
static boolean	isIndexable(java.lang.reflect.Type type) Indicates if the type is considered indexable (ie is a List, an array or a Map).
static boolean	isIterable(java.lang.reflect.Type type)
static boolean	isList(java.lang.reflect.Type type)
static boolean	isMap(java.lang.reflect.Type type)
static java.lang.reflect.Type	typeOf(java.lang.reflect.Executable executable, int parameterIndex) Returns the type of the parameter of the given method with the given parameter index.
static java.lang.reflect.Type	typeOf(java.lang.reflect.Member member)
static java.lang.Class<?>	unBoxedType(java.lang.Class<?> type) Returns the primitive type for a boxed type.

Methods inherited from class java.lang.Object

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

Field Detail

PROPERTY_ACCESSOR_PREFIXES

public static final java.lang.String[] PROPERTY_ACCESSOR_PREFIXES

Method Detail

getPropertyName

public static java.lang.String getPropertyName(java.lang.reflect.Member member)

Returns the JavaBeans property name of the given member.

For fields, the field name will be returned. For getter methods, the decapitalized property name will be returned, with the "get", "is" or "has" prefix stripped off. Getter methods are methods

• whose name start with "get" and who have a return type but no parameter or
• whose name starts with "is" and who have no parameter and return boolean or
• whose name starts with "has" and who have no parameter and return boolean (HV-specific, not mandated by JavaBeans spec).

Parameters:

member - The member for which to get the property name.

Returns:

The property name for the given member or null if the member is neither a field nor a getter method according to the JavaBeans standard.

isGetterMethod

public static boolean isGetterMethod(java.lang.reflect.Executable executable)

Checks whether the given executable is a valid JavaBeans getter method, which is the case if

• its name starts with "get" and it has a return type but no parameter or
• its name starts with "is", it has no parameter and is returning boolean or
• its name starts with "has", it has no parameter and is returning boolean (HV-specific, not mandated by JavaBeans spec).

Parameters:

executable - The executable of interest.

Returns:

true, if the given executable is a JavaBeans getter method, false otherwise.

typeOf

public static java.lang.reflect.Type typeOf(java.lang.reflect.Member member)

Parameters:

member - The Member instance for which to retrieve the type.

Returns:

Returns the Type of the given Field or Method.

Throws:

java.lang.IllegalArgumentException - in case member is not a Field or Method.

typeOf

public static java.lang.reflect.Type typeOf(java.lang.reflect.Executable executable,
                                            int parameterIndex)

Returns the type of the parameter of the given method with the given parameter index.

Parameters:

executable - The executable of interest.

parameterIndex - The index of the parameter for which the type should be returned.

Returns:

The erased type.

getValue

public static java.lang.Object getValue(java.lang.reflect.Field field,
                                        java.lang.Object object)

getValue

public static java.lang.Object getValue(java.lang.reflect.Method method,
                                        java.lang.Object object)

isCollection

public static boolean isCollection(java.lang.reflect.Type type)

Indicates whether the given type represents a collection of elements or not (i.e. whether it is an Iterable, Map or array type).

getCollectionElementType

public static java.lang.reflect.Type getCollectionElementType(java.lang.reflect.Type type)

Determines the type of the elements of an Iterable, array or the value of a Map.

isIndexable

public static boolean isIndexable(java.lang.reflect.Type type)

Indicates if the type is considered indexable (ie is a List, an array or a Map).

Note that it does not include Sets as they are not indexable.

Parameters:

type - the type to inspect.

Returns:

Returns true if the type is indexable.

getClassFromType

public static java.lang.Class<?> getClassFromType(java.lang.reflect.Type type)

Converts the given Type to a Class.

Parameters:

type - the type to convert

Returns:

the class corresponding to the type

isIterable

public static boolean isIterable(java.lang.reflect.Type type)

Parameters:

type - the type to check.

Returns:

Returns true if type is a iterable type, false otherwise.

isMap

public static boolean isMap(java.lang.reflect.Type type)

Parameters:

type - the type to check.

Returns:

Returns true if type is implementing Map, false otherwise.

isList

public static boolean isList(java.lang.reflect.Type type)

Parameters:

type - the type to check.

Returns:

Returns true if type is implementing List, false otherwise.

getIndexedValue

public static java.lang.Object getIndexedValue(java.lang.Object value,
                                               int index)

Tries to retrieve the indexed value from the specified object.

Parameters:

value - The object from which to retrieve the indexed value. The object has to be non null and either a collection or array.

index - The index.

Returns:

The indexed value or null if value is null or not a collection or array. null is also returned in case the index does not exist.

getMappedValue

public static java.lang.Object getMappedValue(java.lang.Object value,
                                              java.lang.Object key)

Tries to retrieve the mapped value from the specified object.

Parameters:

value - The object from which to retrieve the mapped value. The object has to be non null and must implement the @{code Map} interface.

key - The map key. index.

Returns:

The mapped value or null if value is null or not implementing @{code Map}.

boxedType

public static java.lang.reflect.Type boxedType(java.lang.reflect.Type type)

Returns the corresponding auto-boxed type if given a primitive type. Returns the given type itself otherwise.

boxedType

public static java.lang.Class<?> boxedType(java.lang.Class<?> type)

Returns the corresponding auto-boxed type if given a primitive type. Returns the given type itself otherwise.

unBoxedType

public static java.lang.Class<?> unBoxedType(java.lang.Class<?> type)

Returns the primitive type for a boxed type.

Parameters:

type - the boxed type

Returns:

the primitive type for a auto-boxed type. In case Void is passed (which is considered as primitive type by Class.isPrimitive()), Void will be returned.

Throws:

java.lang.IllegalArgumentException - in case the parameter primitiveType does not represent a primitive type.