Package org.jvnet.tiger_types

Class Types

java.lang.Object

org.jvnet.tiger_types.Types

public class Types
extends Object

Type arithmetic functions.

Author:

Kohsuke Kawaguchi

Constructor Summary

Constructors

Constructor	Description
Types()

Method Summary

Modifier and Type	Method	Description
static Type	bind(Type t, GenericDeclaration decl, ParameterizedType args)	Replaces the type variables in t by its actual values.
static ParameterizedType	createParameterizedType(Class rawType, Type... arguments)	Returns the Type object that represents clazz<T1,T2,T3>.
static <T> Class<T>	erasure(Type t)	Returns the Class representation of the given type.
static Type	getBaseClass(Type type, Class baseType)	Gets the parameterization of the given base type.
static Type	getComponentType(Type t)	Gets the component type of the array.
static Type	getTypeArgument(Type type, int i)	Gets the i-th type argument from a parameterized type.
static Type	getTypeArgument(Type type, int i, Type defaultValue)	Gets the i-th type argument from a parameterized type.
static String	getTypeName(Type type)	Gets the display name of the type object
static boolean	isArray(Type t)	Checks if the type is an array type.
static boolean	isArrayButNotByteArray(Type t)	Checks if the type is an array type but not byte[].
static boolean	isOverriding(Method method, Class base)	Tests if the given method overrides another method defined in 'base' (or its super types.)
static boolean	isPrimitive(Type type)	Checks if the given type is a primitive type.
static boolean	isSubClassOf(Type sub, Type sup)	Checks if sub is a sub-type of sup.

Methods inherited from class java.lang.Object

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

Constructor Detail

Types

public Types()

Method Detail

bind

public static Type bind(Type t,
                        GenericDeclaration decl,
                        ParameterizedType args)

Replaces the type variables in t by its actual values.

This is primarily used to resolve a method of a generic type to a concrete signature.

For example, binding Collection<T> with T=List<String> results in Collection<List<String>>.

Parameters:

decl - provides a list of type variables. See GenericDeclaration.getTypeParameters()

args - actual arguments. See ParameterizedType.getActualTypeArguments()

getBaseClass

public static Type getBaseClass(Type type,
                                Class baseType)

Gets the parameterization of the given base type.

For example, given the following

 interface Foo<T> extends List<List<T>> {}
 interface Bar extends Foo<String> {}
 

This method works like this:

 getBaseClass( Bar, List ) = List<List<String>
 getBaseClass( Bar, Foo  ) = Foo<String>
 getBaseClass( Foo<? extends Number>, Collection ) = Collection<List<? extends Number>>
 getBaseClass( ArrayList<? extends BigInteger>, List ) = List<? extends BigInteger>
 

Parameters:

type - The type that derives from baseType

baseType - The class whose parameterization we are interested in.

Returns:

The use of baseType in type. or null if the type is not assignable to the base type.

getTypeName

public static String getTypeName(Type type)

Gets the display name of the type object

Returns:

a human-readable name that the type represents.

isSubClassOf

public static boolean isSubClassOf(Type sub,
                                   Type sup)

Checks if sub is a sub-type of sup.

erasure

public static <T> Class<T> erasure(Type t)

Returns the Class representation of the given type. This corresponds to the notion of the erasure in JSR-14.

It made me realize how difficult it is to define the common navigation layer for two different underlying reflection library. The other way is to throw away the entire parameterization and go to the wrapper approach.

createParameterizedType

public static ParameterizedType createParameterizedType(Class rawType,
                                                        Type... arguments)

Returns the Type object that represents clazz<T1,T2,T3>.

isArray

public static boolean isArray(Type t)

Checks if the type is an array type.

isArrayButNotByteArray

public static boolean isArrayButNotByteArray(Type t)

Checks if the type is an array type but not byte[].

getComponentType

public static Type getComponentType(Type t)

Gets the component type of the array.

Parameters:

t - must be an array.

getTypeArgument

public static Type getTypeArgument(Type type,
                                   int i)

Gets the i-th type argument from a parameterized type.

Unlike getTypeArgument(Type, int, Type), this method throws IllegalArgumentException if the given type is not parameterized.

getTypeArgument

public static Type getTypeArgument(Type type,
                                   int i,
                                   Type defaultValue)

Gets the i-th type argument from a parameterized type.

For example, getTypeArgument([Map<Integer,String>],0)=Integer If the given type is not a parameterized type, returns the specified default value.

This is convenient for handling raw types and parameterized types uniformly.

Throws:

IndexOutOfBoundsException - If i is out of range.

isPrimitive

public static boolean isPrimitive(Type type)

Checks if the given type is a primitive type.

isOverriding

public static boolean isOverriding(Method method,
                                   Class base)

Tests if the given method overrides another method defined in 'base' (or its super types.)