Package org.eclipse.yasson.internal

Class ReflectionUtils

java.lang.Object

org.eclipse.yasson.internal.ReflectionUtils

public class ReflectionUtils
extends Object

Utility class for resolution of generics during unmarshalling.

Author:

Roman Grigoriadi

Constructor Summary

Constructors

Constructor	Description
ReflectionUtils()

Method Summary

Modifier and Type	Method	Description
static <T> T	createNoArgConstructorInstance(Class<T> clazz)	Search for no argument constructor of a class and create instance.
static ParameterizedType	findParameterizedType(Class<?> classToSearch, Class<?> parameterizedInterface)	For generic adapters like:
static Optional<Class<?>>	getOptionalRawType(Type type)	Get raw type by type.
static Class<?>	getRawType(Type type)	Get raw type by type.
static boolean	isResolvedType(Type type)	Check if type needs resolution.
static Type	resolveItemVariableType(RuntimeTypeInfo item, TypeVariable<?> typeVariable)	Resolve a bounded type variable type by its wrapper types.
static Class<?>	resolveRawType(RuntimeTypeInfo item, Type type)	Get a raw type of any type.
static Type	resolveType(RuntimeTypeInfo item, Type type)	Resolve a type by item.
static Type	resolveTypeArguments(ParameterizedType typeToResolve, Type typeToSearch)	Resolves TypeVariable arguments of generic types.

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

getOptionalRawType

public static Optional<Class<?>> getOptionalRawType(Type type)

Get raw type by type. Only for ParametrizedTypes, GenericArrayTypes and Classes. Empty optional is returned if raw type cannot be resolved.

Parameters:

type - Type to get class information from, not null.

Returns:

Class of a type.

getRawType

public static Class<?> getRawType(Type type)

Get raw type by type. Resolves only ParametrizedTypes, GenericArrayTypes and Classes. Exception is thrown if raw type cannot be resolved.

Parameters:

type - Type to get class information from, not null.

Returns:

Class of a raw type.

resolveRawType

public static Class<?> resolveRawType(RuntimeTypeInfo item,
                                      Type type)

Get a raw type of any type. If type is a TypeVariable recursively search AbstractItem for resolution of typevar. If type is a WildcardType find most specific upper / lower bound, which can be used. If most specific bound is a TypeVariable, perform typevar resolution.

Parameters:

item - item containing wrapper class of a type field, not null.

type - type to resolve, typically field type or generic bound, not null.

Returns:

resolved raw class

resolveType

public static Type resolveType(RuntimeTypeInfo item,
                               Type type)

Resolve a type by item. If type is a TypeVariable recursively search AbstractItem for resolution of typevar. If type is a WildcardType find most specific upper / lower bound, which can be used. If most specific bound is a TypeVariable, perform typevar resolution.

Parameters:

item - item containing wrapper class of a type field, not null.

type - type to resolve, typically field type or generic bound, not null.

Returns:

resolved type

resolveItemVariableType

public static Type resolveItemVariableType(RuntimeTypeInfo item,
                                           TypeVariable<?> typeVariable)

Resolve a bounded type variable type by its wrapper types. Resolution could be done only if a compile time generic information is provided, either: by generic field or subclass of a generic class.

Parameters:

item - item to search "runtime" generic type of a TypeVariable.

typeVariable - type to search in item for, not null.

Returns:

Type of a generic "runtime" bound, not null.

resolveTypeArguments

public static Type resolveTypeArguments(ParameterizedType typeToResolve,
                                        Type typeToSearch)

Resolves TypeVariable arguments of generic types.

Parameters:

typeToResolve - type to resolve

typeToSearch - type to search

Returns:

resolved type

createNoArgConstructorInstance

public static <T> T createNoArgConstructorInstance(Class<T> clazz)

Search for no argument constructor of a class and create instance.

Type Parameters:

T - type of instance

Parameters:

clazz - not null

Returns:

instance

findParameterizedType

public static ParameterizedType findParameterizedType(Class<?> classToSearch,
                                                      Class<?> parameterizedInterface)

For generic adapters like:

interface ContainerAdapter<T> extends JsonbAdapter<Box<T>, Crate<T>>...; class IntegerBoxToCrateAdapter implements ContainerAdapter<Integer>...;

We need to find a JsonbAdapter class which will hold basic generic type arguments, and resolve them if they are TypeVariables from there.

Parameters:

classToSearch - class to resolve parameterized interface

parameterizedInterface - interface to search

Returns:

type of JsonbAdapter

isResolvedType

public static boolean isResolvedType(Type type)

Check if type needs resolution. If type is a class or a parametrized type with all type arguments as classes than it is considered resolved. If any of types is type variable or wildcard type is not resolved.

Parameters:

type - Type to check.

Returns:

True if resolved