Package com.restfb.util

Class ReflectionUtils

java.lang.Object

com.restfb.util.ReflectionUtils

public final class ReflectionUtils
extends Object

A collection of reflection-related utility methods.

Since:

1.6

Author:

Mark Allen, Igor Kabiljo, Scott Hernandez

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ReflectionUtils.FieldWithAnnotation<T extends Annotation>	A field/annotation pair.

Method Summary

Modifier and Type	Method	Description
static <T> T	createInstance(Class<T> type)	Creates a new instance of the given type.
static boolean	equals(Object object1, Object object2)	Reflection-based implementation of Object.equals(Object).
static <T extends Annotation> List<ReflectionUtils.FieldWithAnnotation<T>>	findFieldsWithAnnotation(Class<?> type, Class<T> annotationType)	Finds fields on the given type and all of its superclasses annotated with annotations of type annotationType.
static <T extends Annotation> List<Method>	findMethodsWithAnnotation(Class<?> type, Class<T> annotationType)	Finds methods on the given type and all of its superclasses annotated with annotations of type annotationType.
static List<Method>	getAccessors(Class<?> clazz)	Gets all accessor methods for the given clazz.
static Class<?>	getFirstParameterizedTypeArgument(Field field)	For a given field, get its first parameterized type argument.
static Class<?>	getSecondParameterizedTypeArgument(Field field)	For a given field, get its second parameterized type argument.
static int	hashCode(Object object)	Reflection-based implementation of Object.hashCode().
static boolean	isPrimitive(Object object)	Is the given object a primitive type or wrapper for a primitive type?
static void	setJson(Object cls, String obj)
static String	toString(Object object)	Reflection-based implementation of Object.toString().

Methods inherited from class java.lang.Object

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

Method Detail

setJson

public static void setJson(Object cls,
                           String obj)

isPrimitive

public static boolean isPrimitive(Object object)

Is the given object a primitive type or wrapper for a primitive type?

Parameters:

object - The object to check for primitive-ness.

Returns:

true if object is a primitive type or wrapper for a primitive type, false otherwise.

findFieldsWithAnnotation

public static <T extends Annotation> List<ReflectionUtils.FieldWithAnnotation<T>> findFieldsWithAnnotation(Class<?> type,
                                                                                                           Class<T> annotationType)

Finds fields on the given type and all of its superclasses annotated with annotations of type annotationType.

Type Parameters:

T - The annotation type.

Parameters:

type - The target type token.

annotationType - The annotation type token.

Returns:

A list of field/annotation pairs.

findMethodsWithAnnotation

public static <T extends Annotation> List<Method> findMethodsWithAnnotation(Class<?> type,
                                                                            Class<T> annotationType)

Finds methods on the given type and all of its superclasses annotated with annotations of type annotationType.

These results are cached to mitigate performance overhead.

Type Parameters:

T - The annotation type.

Parameters:

type - The target type token.

annotationType - The annotation type token.

Returns:

A list of methods with the given annotation.

Since:

1.6.11

getFirstParameterizedTypeArgument

public static Class<?> getFirstParameterizedTypeArgument(Field field)

For a given field, get its first parameterized type argument.

For example, a field of type List<Long> would have a first type argument of Long.class.

If the field has no type arguments, null is returned.

Parameters:

field - The field to check.

Returns:

The field's first parameterized type argument, or null if none exists.

getSecondParameterizedTypeArgument

public static Class<?> getSecondParameterizedTypeArgument(Field field)

For a given field, get its second parameterized type argument. If the field has no type arguments, null is returned.

Parameters:

field - The field to check.

Returns:

The field's second parameterized type argument, or null if none exists.

getAccessors

public static List<Method> getAccessors(Class<?> clazz)

Gets all accessor methods for the given clazz.

Parameters:

clazz - The class for which accessors are extracted.

Returns:

All accessor methods for the given clazz.

toString

public static String toString(Object object)

Reflection-based implementation of Object.toString().

Parameters:

object - The object to convert to a string representation.

Returns:

A string representation of object.

Throws:

IllegalStateException - If an error occurs while performing reflection operations.

hashCode

public static int hashCode(Object object)

Reflection-based implementation of Object.hashCode().

Parameters:

object - The object to hash.

Returns:

A hashcode for object.

Throws:

IllegalStateException - If an error occurs while performing reflection operations.

equals

public static boolean equals(Object object1,
                             Object object2)

Reflection-based implementation of Object.equals(Object).

Parameters:

object1 - One object to compare.

object2 - Another object to compare.

Returns:

true if the objects are equal, false otherwise.

Throws:

IllegalStateException - If an error occurs while performing reflection operations.

createInstance

public static <T> T createInstance(Class<T> type)

Creates a new instance of the given type.

Type Parameters:

T - Java type to map to.

Parameters:

type - Type token.

Returns:

A new instance of type.

Throws:

FacebookJsonMappingException - If an error occurs when creating a new instance (type is inaccessible, doesn't have a no-arg constructor, etc.)