io.micronaut.core.reflect

Class ReflectionUtils

java.lang.Object

io.micronaut.core.reflect.ReflectionUtils

@Internal
public class ReflectionUtils
extends Object

Utility methods for reflection related tasks. Micronaut tries to avoid using reflection wherever possible, this class is therefore considered an internal class and covers edge cases needed by Micronaut, often at compile time. Do not use in application code.

Since:

1.0

Author:

Graeme Rocher

Field Summary

Fields

Modifier and Type	Field and Description
static Class[]	EMPTY_CLASS_ARRAY Constant for empty class array.

Constructor Summary

Constructors

Constructor and Description
ReflectionUtils()

Method Summary

Modifier and Type	Method and Description
static <T> Optional<Constructor<T>>	findConstructor(Class<T> type, Class... argTypes) Obtains a declared method.
static Optional<Field>	findDeclaredField(Class type, String name)
static Optional<Field>	findField(Class type, String name) Finds a field in the type or super type.
static Optional<Method>	findMethod(Class type, String name, Class... argumentTypes) Finds a method on the given type for the given name.
static Stream<Method>	findMethodsByName(Class type, String name) Finds a method on the given type for the given name.
static Set<Class>	getAllInterfaces(Class<?> aClass)
static Optional<Method>	getDeclaredMethod(Class type, String methodName, Class... argTypes) Obtains a declared method.
static Object	getField(Class clazz, String fieldName, Object instance) Gets the value of the given field reflectively.
static Optional<Method>	getMethod(Class type, String methodName, Class... argTypes) Obtains a method.
static Class	getPrimitiveType(Class wrapperType) Obtain the primitive type for the given wrapper type.
static Field	getRequiredField(Class type, String name) Finds a field on the given type for the given name.
static <T> Constructor<T>	getRequiredInternalConstructor(Class<T> type, Class... argumentTypes) Finds an internal constructor defined by the Micronaut API and throws a NoSuchMethodError if it doesn't exist.
static Method	getRequiredInternalMethod(Class type, String name, Class... argumentTypes) Finds an internal method defined by the Micronaut API and throws a NoSuchMethodError if it doesn't exist.
static Method	getRequiredMethod(Class type, String name, Class... argumentTypes) Finds a method on the given type for the given name.
static Class	getWrapperType(Class primitiveType) Obtain the wrapper type for the given primitive.
static <R,T> R	invokeMethod(T instance, Method method, Object... arguments) Invokes a method.
static boolean	isSetter(String name, Class[] args) Is the method a setter.
static NoSuchMethodError	newNoSuchMethodError(Class declaringType, String name, Class[] argumentTypes)
protected static Set<Class>	populateInterfaces(Class<?> aClass, Set<Class> interfaces)
static void	setField(Field field, Object instance, Object value) Sets the value of the given field reflectively.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_CLASS_ARRAY

public static final Class[] EMPTY_CLASS_ARRAY

Constant for empty class array.

Constructor Detail

ReflectionUtils

public ReflectionUtils()

Method Detail

isSetter

public static boolean isSetter(String name,
                               Class[] args)

Is the method a setter.

Parameters:

name - The method name

args - The arguments

Returns:

True if it is

getWrapperType

public static Class getWrapperType(Class primitiveType)

Obtain the wrapper type for the given primitive.

Parameters:

primitiveType - The primitive type

Returns:

The wrapper type

getPrimitiveType

public static Class getPrimitiveType(Class wrapperType)

Obtain the primitive type for the given wrapper type.

Parameters:

wrapperType - The primitive type

Returns:

The wrapper type

getDeclaredMethod

public static Optional<Method> getDeclaredMethod(Class type,
                                                 String methodName,
                                                 Class... argTypes)

Obtains a declared method.

Parameters:

type - The type

methodName - The method name

argTypes - The argument types

Returns:

The method

getMethod

public static Optional<Method> getMethod(Class type,
                                         String methodName,
                                         Class... argTypes)

Obtains a method.

Parameters:

type - The type

methodName - The method name

argTypes - The argument types

Returns:

An optional Method

findConstructor

public static <T> Optional<Constructor<T>> findConstructor(Class<T> type,
                                                           Class... argTypes)

Obtains a declared method.

Type Parameters:

T - The generic type

Parameters:

type - The type

argTypes - The argument types

Returns:

The method

invokeMethod

public static <R,T> R invokeMethod(T instance,
                                   Method method,
                                   Object... arguments)

Invokes a method.

Type Parameters:

R - The return type

T - The instance type

Parameters:

instance - The instance

method - The method

arguments - The arguments

Returns:

The result

findMethod

@Internal
public static Optional<Method> findMethod(Class type,
                                                    String name,
                                                    Class... argumentTypes)

Finds a method on the given type for the given name.

Parameters:

type - The type

name - The name

argumentTypes - The argument types

Returns:

An Optional contains the method or empty

getRequiredMethod

@Internal
public static Method getRequiredMethod(Class type,
                                                 String name,
                                                 Class... argumentTypes)

Finds a method on the given type for the given name.

Parameters:

type - The type

name - The name

argumentTypes - The argument types

Returns:

An Optional contains the method or empty

getRequiredInternalMethod

@Internal
public static Method getRequiredInternalMethod(Class type,
                                                         String name,
                                                         Class... argumentTypes)

Finds an internal method defined by the Micronaut API and throws a NoSuchMethodError if it doesn't exist.

Parameters:

type - The type

name - The name

argumentTypes - The argument types

Returns:

An Optional contains the method or empty

Throws:

NoSuchMethodError - If the method doesn't exist

getRequiredInternalConstructor

@Internal
public static <T> Constructor<T> getRequiredInternalConstructor(Class<T> type,
                                                                          Class... argumentTypes)

Finds an internal constructor defined by the Micronaut API and throws a NoSuchMethodError if it doesn't exist.

Type Parameters:

T - The type

Parameters:

type - The type

argumentTypes - The argument types

Returns:

An Optional contains the method or empty

Throws:

NoSuchMethodError - If the method doesn't exist

getRequiredField

@Internal
public static Field getRequiredField(Class type,
                                               String name)

Finds a field on the given type for the given name.

Parameters:

type - The type

name - The name

Returns:

An Optional contains the method or empty

findField

@Internal
public static Optional<Field> findField(Class type,
                                                  String name)

Finds a field in the type or super type.

Parameters:

type - The type

name - The field name

Returns:

An Optional of field

findMethodsByName

public static Stream<Method> findMethodsByName(Class type,
                                               String name)

Finds a method on the given type for the given name.

Parameters:

type - The type

name - The name

Returns:

An Optional contains the method or empty

findDeclaredField

public static Optional<Field> findDeclaredField(Class type,
                                                String name)

Parameters:

type - The type

name - The field name

Returns:

An optional with the declared field

getAllInterfaces

public static Set<Class> getAllInterfaces(Class<?> aClass)

Parameters:

aClass - A class

Returns:

All the interfaces

populateInterfaces

protected static Set<Class> populateInterfaces(Class<?> aClass,
                                               Set<Class> interfaces)

Parameters:

aClass - A class

interfaces - The interfaces

Returns:

A set with the interfaces

newNoSuchMethodError

public static NoSuchMethodError newNoSuchMethodError(Class declaringType,
                                                     String name,
                                                     Class[] argumentTypes)

Parameters:

declaringType - The declaring type

name - The method name

argumentTypes - The argument types

Returns:

A NoSuchMethodError

setField

public static void setField(@NonNull
                            Field field,
                            @NonNull
                            Object instance,
                            @Nullable
                            Object value)

Sets the value of the given field reflectively.

Parameters:

field - The field

instance - The instance

value - The value

getField

public static Object getField(@NonNull
                              Class clazz,
                              @NonNull
                              String fieldName,
                              @NonNull
                              Object instance)

Gets the value of the given field reflectively.

Parameters:

clazz - The class

fieldName - The fieldName

instance - The instance

Returns:

field value of instance

Since:

3.7.0