org.hibernate.util

Class ReflectHelper

java.lang.Object

org.hibernate.util.ReflectHelper

public final class ReflectHelper
extends java.lang.Object

Utility class for various reflection operations.

Author:

Gavin King, Steve Ebersole

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.Class[]	NO_PARAM_SIGNATURE
static java.lang.Object[]	NO_PARAMS
static java.lang.Class[]	SINGLE_OBJECT_PARAM_SIGNATURE

Method Summary

Methods

Modifier and Type	Method and Description
static java.lang.Class	classForName(java.lang.String name) Perform resolution of a class name.
static java.lang.Class	classForName(java.lang.String name, java.lang.Class caller) Perform resolution of a class name.
static java.lang.reflect.Method	extractEqualsMethod(java.lang.Class clazz) Encapsulation of getting hold of a class's equals method.
static java.lang.reflect.Method	extractHashCodeMethod(java.lang.Class clazz) Encapsulation of getting hold of a class's hashCode method.
static java.lang.Object	getConstantValue(java.lang.String name) Resolve a constant to its actual value.
static java.lang.reflect.Constructor	getConstructor(java.lang.Class clazz, Type[] types) Retrieve a constructor for the given class, with arguments matching the specified Hibernate mapping types.
static java.lang.reflect.Constructor	getDefaultConstructor(java.lang.Class clazz) Retrieve the default (no arg) constructor from the given class.
static Getter	getGetter(java.lang.Class theClass, java.lang.String name) Directly retrieve the Getter reference via the BasicPropertyAccessor.
static java.lang.reflect.Method	getMethod(java.lang.Class clazz, java.lang.reflect.Method method)
static boolean	implementsInterface(java.lang.Class clazz, java.lang.Class intf) Determine if the given class implements the given interface.
static boolean	isAbstractClass(java.lang.Class clazz) Determine if the given class is declared abstract.
static boolean	isFinalClass(java.lang.Class clazz) Determine is the given class is declared final.
static boolean	isPublic(java.lang.Class clazz, java.lang.reflect.Member member) Is this member publicly accessible.
static boolean	isPublic(java.lang.reflect.Member member) Is this member publicly accessible.
static boolean	overridesEquals(java.lang.Class clazz) Determine if the given class defines an Object.equals(java.lang.Object) override.
static boolean	overridesHashCode(java.lang.Class clazz) Determine if the given class defines a Object.hashCode() override.
static java.lang.Class	reflectedPropertyClass(java.lang.String className, java.lang.String name) Attempt to resolve the specified property type through reflection.

Methods inherited from class java.lang.Object

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

Field Detail

NO_PARAM_SIGNATURE

public static final java.lang.Class[] NO_PARAM_SIGNATURE

NO_PARAMS

public static final java.lang.Object[] NO_PARAMS

SINGLE_OBJECT_PARAM_SIGNATURE

public static final java.lang.Class[] SINGLE_OBJECT_PARAM_SIGNATURE

Method Detail

extractEqualsMethod

public static java.lang.reflect.Method extractEqualsMethod(java.lang.Class clazz)
                                                    throws java.lang.NoSuchMethodException

Encapsulation of getting hold of a class's equals method.

Parameters:

clazz - The class from which to extract the equals method.

Returns:

The equals method reference

Throws:

java.lang.NoSuchMethodException - Should indicate an attempt to extract equals method from interface.

extractHashCodeMethod

public static java.lang.reflect.Method extractHashCodeMethod(java.lang.Class clazz)
                                                      throws java.lang.NoSuchMethodException

Encapsulation of getting hold of a class's hashCode method.

Parameters:

clazz - The class from which to extract the hashCode method.

Returns:

The hashCode method reference

Throws:

java.lang.NoSuchMethodException - Should indicate an attempt to extract hashCode method from interface.

overridesEquals

public static boolean overridesEquals(java.lang.Class clazz)

Determine if the given class defines an Object.equals(java.lang.Object) override.

Parameters:

clazz - The class to check

Returns:

True if clazz defines an equals override.

overridesHashCode

public static boolean overridesHashCode(java.lang.Class clazz)

Determine if the given class defines a Object.hashCode() override.

Parameters:

clazz - The class to check

Returns:

True if clazz defines an hashCode override.

implementsInterface

public static boolean implementsInterface(java.lang.Class clazz,
                          java.lang.Class intf)

Determine if the given class implements the given interface.

Parameters:

clazz - The class to check

intf - The interface to check it against.

Returns:

True if the class does implement the interface, false otherwise.

classForName

public static java.lang.Class classForName(java.lang.String name,
                           java.lang.Class caller)
                                    throws java.lang.ClassNotFoundException

Perform resolution of a class name.

Here we first check the context classloader, if one, before delegating to Class.forName(String, boolean, ClassLoader) using the caller's classloader

Parameters:

name - The class name

caller - The class from which this call originated (in order to access that class's loader).

Returns:

The class reference.

Throws:

java.lang.ClassNotFoundException - From Class.forName(String, boolean, ClassLoader).

classForName

public static java.lang.Class classForName(java.lang.String name)
                                    throws java.lang.ClassNotFoundException

Perform resolution of a class name.

Same as classForName(String, Class) except that here we delegate to Class.forName(String) if the context classloader lookup is unsuccessful.

Parameters:

name - The class name

Returns:

The class reference.

Throws:

java.lang.ClassNotFoundException - From Class.forName(String).

isPublic

public static boolean isPublic(java.lang.reflect.Member member)

Is this member publicly accessible.

Short-hand for isPublic(Class, Member) passing the member + Member.getDeclaringClass()

Parameters:

member - The member to check

Returns:

True if the member is publicly accessible.

isPublic

public static boolean isPublic(java.lang.Class clazz,
               java.lang.reflect.Member member)

Is this member publicly accessible.

Parameters:

clazz - The class which defines the member

member - The memeber.

Returns:

True if the member is publicly accessible, false otherwise.

reflectedPropertyClass

public static java.lang.Class reflectedPropertyClass(java.lang.String className,
                                     java.lang.String name)
                                              throws MappingException

Attempt to resolve the specified property type through reflection.

Parameters:

className - The name of the class owning the property.

name - The name of the property.

Returns:

The type of the property.

Throws:

MappingException - Indicates we were unable to locate the property.

getGetter

public static Getter getGetter(java.lang.Class theClass,
               java.lang.String name)
                        throws MappingException

Directly retrieve the Getter reference via the BasicPropertyAccessor.

Parameters:

theClass - The class owning the property

name - The name of the property

Returns:

The getter.

Throws:

MappingException - Indicates we were unable to locate the property.

getConstantValue

public static java.lang.Object getConstantValue(java.lang.String name)

Resolve a constant to its actual value.

Parameters:

name - The name

Returns:

The value

getDefaultConstructor

public static java.lang.reflect.Constructor getDefaultConstructor(java.lang.Class clazz)
                                                           throws PropertyNotFoundException

Retrieve the default (no arg) constructor from the given class.

Parameters:

clazz - The class for which to retrieve the default ctor.

Returns:

The default constructor.

Throws:

PropertyNotFoundException - Indicates there was not publicly accessible, no-arg constructor (todo : why PropertyNotFoundException???)

isAbstractClass

public static boolean isAbstractClass(java.lang.Class clazz)

Determine if the given class is declared abstract.

Parameters:

clazz - The class to check.

Returns:

True if the class is abstract, false otherwise.

isFinalClass

public static boolean isFinalClass(java.lang.Class clazz)

Determine is the given class is declared final.

Parameters:

clazz - The class to check.

Returns:

True if the class is final, flase otherwise.

getConstructor

public static java.lang.reflect.Constructor getConstructor(java.lang.Class clazz,
                                           Type[] types)
                                                    throws PropertyNotFoundException

Retrieve a constructor for the given class, with arguments matching the specified Hibernate mapping types.

Parameters:

clazz - The class needing instantiation

types - The types representing the required ctor param signature

Returns:

The matching constructor.

Throws:

PropertyNotFoundException - Indicates we could not locate an appropriate constructor (todo : again with PropertyNotFoundException???)

getMethod

public static java.lang.reflect.Method getMethod(java.lang.Class clazz,
                                 java.lang.reflect.Method method)