net.sf.mmm.util.reflect.base

Class SimpleGenericTypeLimited<T>

java.lang.Object

net.sf.mmm.util.reflect.base.SimpleGenericTypeLimited<T>

Type Parameters:

T - is the generic type of the retrieval class.

All Implemented Interfaces:

Type, GenericType<T>

public class SimpleGenericTypeLimited<T>
extends Object
implements GenericType<T>

This is a very simple implementation of GenericType that is GWT compatible and therefore limited to core features.

Since:

3.1.0

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

Field Summary

Fields

Modifier and Type	Field and Description
private GenericType<?>	componentType
private GenericType<?>	keyType
private Class<T>	type
static GenericType<Object>	TYPE_OBJECT The GenericType for Object.
static GenericType<Void>	TYPE_VOID The GenericType for Void.

Fields inherited from interface net.sf.mmm.util.reflect.api.GenericType

NO_TYPES

Constructor Summary

Constructors

Constructor and Description
SimpleGenericTypeLimited(Class<T> type) The constructor.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
Class<T>	getAssignmentClass() This method gets the Class to be used for assignment (as parameter) of a value of this GenericType.
GenericType<?>	getComponentType() This method gets the component-type of this GenericType if it represents an array, Collection or Map.
GenericType<?>	getKeyType() This method gets the key-type of this GenericType if it represents a Map.
Class<T>	getRetrievalClass() This method gets the Class to be used for retrieval (the return-type) of a value of this GenericType.
Type	getType() This method gets the Type represented by this GenericType.
GenericType<?>	getTypeArgument(int index) This method gets the type-argument at the given index.
int	getTypeArgumentCount() This method gets the number of type-arguments .
int	hashCode()
boolean	isAssignableFrom(GenericType<?> subType) This method determines if this GenericType is equal to or a super-type of the given subType.
private boolean	isCollection(Class<?> rawType) This method determines if the given type is a List.
private boolean	isMap(Class<?> rawType) This method determines if the given type is a Map.

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.mmm.util.reflect.api.GenericType

toString

Methods inherited from interface java.lang.reflect.Type

getTypeName

Field Detail

TYPE_OBJECT

public static final GenericType<Object> TYPE_OBJECT

The GenericType for Object.

TYPE_VOID

public static final GenericType<Void> TYPE_VOID

The GenericType for Void.

type

private final Class<T> type

See Also:

getType()

componentType

private GenericType<?> componentType

See Also:

getComponentType()

keyType

private GenericType<?> keyType

See Also:

getKeyType()

Constructor Detail

SimpleGenericTypeLimited

public SimpleGenericTypeLimited(Class<T> type)

The constructor.

Parameters:

type - is the type to represent.

Method Detail

isCollection

private boolean isCollection(Class<?> rawType)

This method determines if the given type is a List.

Parameters:

rawType - is the Class to check.

Returns:

true if the given type is assignable to List.

isMap

private boolean isMap(Class<?> rawType)

This method determines if the given type is a Map.

Parameters:

rawType - is the Class to check.

Returns:

true if the given type is assignable to Map.

getComponentType

public GenericType<?> getComponentType()

This method gets the component-type of this GenericType if it represents an array, Collection or Map.
Here are some examples:

type	GenericType.getComponentType()
List<Map<String, Long>>	Map<String, Long>
List	Object
Foo[]	Foo
Foo<Bar>[]	Foo<Bar>
Foo<Bar>	null
Map<String, Long>	Long

Specified by:

getComponentType in interface GenericType<T>

Returns:

the component-type of this GenericType or null if this GenericType does NOT represent an array, Collection or Map.

getKeyType

public GenericType<?> getKeyType()

This method gets the key-type of this GenericType if it represents a Map.
Here are some examples:

type	GenericType.getComponentType()
List<Map<String, Long>>	null
Map	Object
Foo[]	null
Foo<K,V>	null
Map<String, Long>	String

Specified by:

getKeyType in interface GenericType<T>

Returns:

the key-type of this GenericType or null if this GenericType does NOT represent a Map.

getType

public Type getType()

This method gets the Type represented by this GenericType.

Specified by:

getType in interface GenericType<T>

Returns:

the value-type.

See Also:

Class.getGenericSuperclass(), Class.getGenericInterfaces(), Method.getGenericReturnType(), Method.getGenericParameterTypes(), Field.getGenericType(), Constructor.getGenericParameterTypes()

getAssignmentClass

public Class<T> getAssignmentClass()

This method gets the Class to be used for assignment (as parameter) of a value of this GenericType.
It will only differ from the retrieval-class if this GenericType is a WildcardType.
Unlike the lower-bound, the assignment-class is never null. If there is no lower-bound, the assignment-class is the same as the retrieval-class. Therefore the assignment-class is always equal or more specific to the retrieval-class.
Here are some examples:

Type	GenericType.getAssignmentClass()
<? super Integer>	Integer
<? extends CharSequence>	CharSequence
String	String

Specified by:

getAssignmentClass in interface GenericType<T>

Returns:

the Class that is the lower bound.

getRetrievalClass

public Class<T> getRetrievalClass()

This method gets the Class to be used for retrieval (the return-type) of a value of this GenericType.
It will only differ from the assignment-class if this GenericType is a WildcardType.
The retrieval-class is the upper-bound, however for usability and simplicity only one bound is supported.
Here are some examples:

Type	GenericType.getAssignmentClass()
<? super Integer>	Object
<? extends CharSequence>	CharSequence
String	String

Specified by:

getRetrievalClass in interface GenericType<T>

Returns:

the Class that is the upper bound.

getTypeArgument

public GenericType<?> getTypeArgument(int index)

This method gets the type-argument at the given index.
E.g. for the GenericType representing Map<String, List<Integer>> this method would return String for an index of 0 and List<Integer> for an index of 1.

Specified by:

getTypeArgument in interface GenericType<T>

Parameters:

index - is the position of the requested type-argument. It has to be in the range from 0 to GenericType.getTypeArgumentCount() - 1.

Returns:

the type-argument at the given index.

See Also:

GenericType.getTypeArgumentCount(), ParameterizedType.getActualTypeArguments()

getTypeArgumentCount

public int getTypeArgumentCount()

This method gets the number of type-arguments .

Specified by:

getTypeArgumentCount in interface GenericType<T>

Returns:

the type-argument count.

isAssignableFrom

public boolean isAssignableFrom(GenericType<?> subType)

This method determines if this GenericType is equal to or a super-type of the given subType.
If X.isAssignableFrom(Y) is true, then an instance of Y can be casted to X.
NOTE:
In case of strange and deeply cascaded generic constructs this can be an expensive operation with many recursive invocations.

Specified by:

isAssignableFrom in interface GenericType<T>

Parameters:

subType - is the potential sub-type of this GenericType.

Returns:

true if objects of the type subType can be assigned to this GenericType.

See Also:

Class.isAssignableFrom(Class)

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object