org.eclipse.sisu.inject

Class TypeArguments

java.lang.Object

org.eclipse.sisu.inject.TypeArguments

public final class TypeArguments
extends java.lang.Object

Utility methods for dealing with generic type arguments.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static interface	TypeArguments.Implicit Qualifier of bindings that should be treated as implicit.

Field Summary

Fields

Modifier and Type	Field and Description
private static com.google.inject.TypeLiteral<?>[]	NO_TYPE_LITERALS
private static com.google.inject.TypeLiteral<java.lang.Object>	OBJECT_TYPE_LITERAL

Constructor Summary

Constructors

Modifier	Constructor and Description
private	TypeArguments()

Method Summary

Modifier and Type	Method and Description
private static com.google.inject.TypeLiteral<?>	expand(java.lang.reflect.Type type) Expands wild-card types where possible, for example Bar from ? extends Bar.
static com.google.inject.TypeLiteral<?>[]	get(com.google.inject.TypeLiteral<?> typeLiteral) Get all type arguments from a generic type, for example [Foo,Bar] from Map<Foo,Bar>.
static com.google.inject.TypeLiteral<?>	get(com.google.inject.TypeLiteral<?> typeLiteral, int index) Get an indexed type argument from a generic type, for example Bar from Map<Foo,Bar>.
static <T> com.google.inject.Key<T>	implicitKey(java.lang.Class<T> clazz) Creates a special binding key for the given implicit type.
private static boolean	isAssignableFrom(java.lang.reflect.Type[] superArgs, java.lang.reflect.Type[] subArgs) Determines whether the resolved sub-type arguments can be assigned to their generic super-type arguments.
static boolean	isAssignableFrom(com.google.inject.TypeLiteral<?> superLiteral, com.google.inject.TypeLiteral<?> subLiteral) Determines if the sub-type can be converted to the generic super-type via an identity or widening conversion.
static boolean	isConcrete(java.lang.Class<?> clazz) Determines if the given raw type represents a concrete type.
static boolean	isConcrete(com.google.inject.TypeLiteral<?> literal) Determines if the given generic type represents a concrete type.
static boolean	isImplicit(java.lang.Class<?> clazz) Determines if the given raw type represents an implicit binding.
static boolean	isImplicit(com.google.inject.TypeLiteral<?> literal) Determines if the given generic type represents an implicit binding.

Methods inherited from class java.lang.Object

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

Field Detail

OBJECT_TYPE_LITERAL

private static final com.google.inject.TypeLiteral<java.lang.Object> OBJECT_TYPE_LITERAL

NO_TYPE_LITERALS

private static final com.google.inject.TypeLiteral<?>[] NO_TYPE_LITERALS

Constructor Detail

TypeArguments

private TypeArguments()

Method Detail

get

public static com.google.inject.TypeLiteral<?>[] get(com.google.inject.TypeLiteral<?> typeLiteral)

Get all type arguments from a generic type, for example [Foo,Bar] from Map<Foo,Bar>.

Parameters:

typeLiteral - The generic type

Returns:

Array of type arguments

get

public static com.google.inject.TypeLiteral<?> get(com.google.inject.TypeLiteral<?> typeLiteral,
                                                   int index)

Get an indexed type argument from a generic type, for example Bar from Map<Foo,Bar>.

Parameters:

typeLiteral - The generic type

index - The argument index

Returns:

Indexed type argument; TypeLiteral<Object> if the given type is a raw class

isAssignableFrom

public static boolean isAssignableFrom(com.google.inject.TypeLiteral<?> superLiteral,
                                       com.google.inject.TypeLiteral<?> subLiteral)

Determines if the sub-type can be converted to the generic super-type via an identity or widening conversion.

Parameters:

superLiteral - The generic super-type

subLiteral - The generic sub-type

Returns:

true if the sub-type can be converted to the generic super-type; otherwise false

See Also:

Class.isAssignableFrom(Class)

isConcrete

public static boolean isConcrete(com.google.inject.TypeLiteral<?> literal)

Determines if the given generic type represents a concrete type.

Parameters:

literal - The generic type

Returns:

true if the generic type is concrete; otherwise false

isConcrete

public static boolean isConcrete(java.lang.Class<?> clazz)

Determines if the given raw type represents a concrete type.

Parameters:

clazz - The raw type

Returns:

true if the raw type is concrete; otherwise false

isImplicit

public static boolean isImplicit(com.google.inject.TypeLiteral<?> literal)

Determines if the given generic type represents an implicit binding.

Parameters:

literal - The generic type

Returns:

true if the generic type is implicit; otherwise false

isImplicit

public static boolean isImplicit(java.lang.Class<?> clazz)

Determines if the given raw type represents an implicit binding.

Parameters:

clazz - The raw type

Returns:

true if the raw type is implicit; otherwise false

implicitKey

public static <T> com.google.inject.Key<T> implicitKey(java.lang.Class<T> clazz)

Creates a special binding key for the given implicit type.

Parameters:

clazz - The implicit type

Returns:

Implicit binding key

expand

private static com.google.inject.TypeLiteral<?> expand(java.lang.reflect.Type type)

Expands wild-card types where possible, for example Bar from ? extends Bar.

Parameters:

type - The generic type

Returns:

Widened type that is still assignment-compatible with the original.

isAssignableFrom

private static boolean isAssignableFrom(java.lang.reflect.Type[] superArgs,
                                        java.lang.reflect.Type[] subArgs)

Determines whether the resolved sub-type arguments can be assigned to their generic super-type arguments.

Parameters:

superArgs - The generic super-arguments

subArgs - The resolved sub-arguments

Returns:

true if all the super-arguments have assignable resolved arguments; otherwise false