org.springframework.data.util

Class ReflectionUtils

java.lang.Object

org.springframework.data.util.ReflectionUtils

public class ReflectionUtils
extends Object

Spring Data specific reflection utility methods and classes.

Since:

1.5

Author:

Oliver Gierke, Thomas Darimont, Christoph Strobl

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ReflectionUtils.AnnotationFieldFilter A ReflectionUtils.FieldFilter for a given annotation.
static interface	ReflectionUtils.DescribedFieldFilter A ReflectionUtils.FieldFilter that has a description.

Constructor Summary

Constructors

Constructor and Description
ReflectionUtils()

Method Summary

Modifier and Type	Method and Description
static <T> T	createInstanceIfPresent(String classname, T defaultInstance) Creates an instance of the class with the given fully qualified name or returns the given default instance if the class cannot be loaded or instantiated.
static Optional<Constructor<?>>	findConstructor(Class<?> type, Object... constructorArguments) Finds a constructor on the given type that matches the given constructor arguments.
static Field	findField(Class<?> type, ReflectionUtils.DescribedFieldFilter filter) Finds the field matching the given ReflectionUtils.DescribedFieldFilter.
static Field	findField(Class<?> type, ReflectionUtils.DescribedFieldFilter filter, boolean enforceUniqueness) Finds the field matching the given ReflectionUtils.DescribedFieldFilter.
static Field	findField(Class<?> type, ReflectionUtils.FieldFilter filter) Finds the first field on the given class matching the given ReflectionUtils.FieldFilter.
static Optional<Method>	getMethod(Class<?> type, String name, ResolvableType... parameterTypes) Returns the Method with the given name and parameters declared on the given type, if available.
static Stream<Class<?>>	returnTypeAndParameters(Method method) Returns a Stream of the return and parameters types of the given Method.
static void	setField(Field field, Object target, Object value) Sets the given field on the given object to the given value.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReflectionUtils

public ReflectionUtils()

Method Detail

createInstanceIfPresent

public static <T> T createInstanceIfPresent(String classname,
                                            T defaultInstance)

Creates an instance of the class with the given fully qualified name or returns the given default instance if the class cannot be loaded or instantiated.

Parameters:

classname - the fully qualified class name to create an instance for.

defaultInstance - the instance to fall back to in case the given class cannot be loaded or instantiated.

Returns:

findField

public static Field findField(Class<?> type,
                              ReflectionUtils.FieldFilter filter)

Finds the first field on the given class matching the given ReflectionUtils.FieldFilter.

Parameters:

type - must not be null.

filter - must not be null.

Returns:

the field matching the filter or null in case no field could be found.

findField

public static Field findField(Class<?> type,
                              ReflectionUtils.DescribedFieldFilter filter)

Finds the field matching the given ReflectionUtils.DescribedFieldFilter. Will make sure there's only one field matching the filter.

Parameters:

type - must not be null.

filter - must not be null.

Returns:

the field matching the given ReflectionUtils.DescribedFieldFilter or null if none found.

Throws:

IllegalStateException - in case more than one matching field is found

See Also:

findField(Class, DescribedFieldFilter, boolean)

findField

public static Field findField(Class<?> type,
                              ReflectionUtils.DescribedFieldFilter filter,
                              boolean enforceUniqueness)

Finds the field matching the given ReflectionUtils.DescribedFieldFilter. Will make sure there's only one field matching the filter in case enforceUniqueness is true.

Parameters:

type - must not be null.

filter - must not be null.

enforceUniqueness - whether to enforce uniqueness of the field

Returns:

the field matching the given ReflectionUtils.DescribedFieldFilter or null if none found.

Throws:

IllegalStateException - if enforceUniqueness is true and more than one matching field is found

setField

public static void setField(Field field,
                            Object target,
                            Object value)

Sets the given field on the given object to the given value. Will make sure the given field is accessible.

Parameters:

field - must not be null.

target - must not be null.

value -

findConstructor

public static Optional<Constructor<?>> findConstructor(Class<?> type,
                                                       Object... constructorArguments)

Finds a constructor on the given type that matches the given constructor arguments.

Parameters:

type - must not be null.

constructorArguments - must not be null.

Returns:

a Constructor that is compatible with the given arguments.

returnTypeAndParameters

public static Stream<Class<?>> returnTypeAndParameters(Method method)

Returns a Stream of the return and parameters types of the given Method.

Parameters:

method - must not be null.

Returns:

Since:

2.0

getMethod

public static Optional<Method> getMethod(Class<?> type,
                                         String name,
                                         ResolvableType... parameterTypes)

Returns the Method with the given name and parameters declared on the given type, if available.

Parameters:

type - must not be null.

name - must not be null or empty.

parameterTypes - must not be null.

Returns:

Since:

2.0