Java compact3 javax.lang.model.util Interface Types（JDK8）

Method Detail

• asElement

  Element asElement(TypeMirror t)

  Returns the element corresponding to a type. The type may be a DeclaredType or TypeVariable. Returns null if the type is not one with a corresponding element.

  Parameters:

  t - the type to map to an element

  Returns:

  the element corresponding to the given type

• isSameType

  boolean isSameType(TypeMirror t1,
                     TypeMirror t2)

  Tests whether two TypeMirror objects represent the same type.

  Caveat: if either of the arguments to this method represents a wildcard, this method will return false. As a consequence, a wildcard is not the same type as itself. This might be surprising at first, but makes sense once you consider that an example like this must be rejected by the compiler:

      List<?> list = new ArrayList<Object>();
      list.add(list.get(0));
   

  Since annotations are only meta-data associated with a type, the set of annotations on either argument is not taken into account when computing whether or not two TypeMirror objects are the same type. In particular, two TypeMirror objects can have different annotations and still be considered the same.

  Parameters:

  t1 - the first type

  t2 - the second type

  Returns:

  true if and only if the two types are the same

• isSubtype

  boolean isSubtype(TypeMirror t1,
                    TypeMirror t2)

  Tests whether one type is a subtype of another. Any type is considered to be a subtype of itself.

  Parameters:

  t1 - the first type

  t2 - the second type

  Returns:

  true if and only if the first type is a subtype of the second

  Throws:

  IllegalArgumentException - if given an executable or package type

  See The Java™ Language Specification:

  4.10 Subtyping

• isAssignable

  boolean isAssignable(TypeMirror t1,
                       TypeMirror t2)

  Tests whether one type is assignable to another.

  Parameters:

  t1 - the first type

  t2 - the second type

  Returns:

  true if and only if the first type is assignable to the second

  Throws:

  IllegalArgumentException - if given an executable or package type

  See The Java™ Language Specification:

  5.2 Assignment Conversion

• contains

  boolean contains(TypeMirror t1,
                   TypeMirror t2)

  Tests whether one type argument contains another.

  Parameters:

  t1 - the first type

  t2 - the second type

  Returns:

  true if and only if the first type contains the second

  Throws:

  IllegalArgumentException - if given an executable or package type

  See The Java™ Language Specification:

  4.5.1.1 Type Argument Containment and Equivalence

• isSubsignature

  boolean isSubsignature(ExecutableType m1,
                         ExecutableType m2)

  Tests whether the signature of one method is a subsignature of another.

  Parameters:

  m1 - the first method

  m2 - the second method

  Returns:

  true if and only if the first signature is a subsignature of the second

  See The Java™ Language Specification:

  8.4.2 Method Signature

• directSupertypes

  List<? extends TypeMirror> directSupertypes(TypeMirror t)

  Returns the direct supertypes of a type. The interface types, if any, will appear last in the list.

  Parameters:

  t - the type being examined

  Returns:

  the direct supertypes, or an empty list if none

  Throws:

  IllegalArgumentException - if given an executable or package type

• erasure

  TypeMirror erasure(TypeMirror t)

  Returns the erasure of a type.

  Parameters:

  t - the type to be erased

  Returns:

  the erasure of the given type

  Throws:

  IllegalArgumentException - if given a package type

  See The Java™ Language Specification:

  4.6 Type Erasure

• boxedClass

  TypeElement boxedClass(PrimitiveType p)

  Returns the class of a boxed value of a given primitive type. That is, boxing conversion is applied.

  Parameters:

  p - the primitive type to be converted

  Returns:

  the class of a boxed value of type p

  See The Java™ Language Specification:

  5.1.7 Boxing Conversion

• unboxedType

  PrimitiveType unboxedType(TypeMirror t)

  Returns the type (a primitive type) of unboxed values of a given type. That is, unboxing conversion is applied.

  Parameters:

  t - the type to be unboxed

  Returns:

  the type of an unboxed value of type t

  Throws:

  IllegalArgumentException - if the given type has no unboxing conversion

  See The Java™ Language Specification:

  5.1.8 Unboxing Conversion

• capture

  TypeMirror capture(TypeMirror t)

  Applies capture conversion to a type.

  Parameters:

  t - the type to be converted

  Returns:

  the result of applying capture conversion

  Throws:

  IllegalArgumentException - if given an executable or package type

  See The Java™ Language Specification:

  5.1.10 Capture Conversion

• getPrimitiveType

  PrimitiveType getPrimitiveType(TypeKind kind)

  Returns a primitive type.

  Parameters:

  kind - the kind of primitive type to return

  Returns:

  a primitive type

  Throws:

  IllegalArgumentException - if kind is not a primitive kind

• getNullType

  NullType getNullType()

  Returns the null type. This is the type of null.

  Returns:

  the null type

• getNoType

  NoType getNoType(TypeKind kind)

  Returns a pseudo-type used where no actual type is appropriate. The kind of type to return may be either VOID or NONE. For packages, use Elements.getPackageElement(CharSequence).asType() instead.

  Parameters:

  kind - the kind of type to return

  Returns:

  a pseudo-type of kind VOID or NONE

  Throws:

  IllegalArgumentException - if kind is not valid

• getArrayType

  ArrayType getArrayType(TypeMirror componentType)

  Returns an array type with the specified component type.

  Parameters:

  componentType - the component type

  Returns:

  an array type with the specified component type.

  Throws:

  IllegalArgumentException - if the component type is not valid for an array

• getWildcardType

  WildcardType getWildcardType(TypeMirror extendsBound,
                               TypeMirror superBound)

  Returns a new wildcard type argument. Either of the wildcard's bounds may be specified, or neither, but not both.

  Parameters:

  extendsBound - the extends (upper) bound, or null if none

  superBound - the super (lower) bound, or null if none

  Returns:

  a new wildcard

  Throws:

  IllegalArgumentException - if bounds are not valid

• getDeclaredType

  DeclaredType getDeclaredType(TypeElement typeElem,
                               TypeMirror... typeArgs)

  Returns the type corresponding to a type element and actual type arguments. Given the type element for Set and the type mirror for String, for example, this method may be used to get the parameterized type Set<String>.

  The number of type arguments must either equal the number of the type element's formal type parameters, or must be zero. If zero, and if the type element is generic, then the type element's raw type is returned.

  If a parameterized type is being returned, its type element must not be contained within a generic outer class. The parameterized type Outer<String>.Inner<Number>, for example, may be constructed by first using this method to get the type Outer<String>, and then invoking getDeclaredType(DeclaredType, TypeElement, TypeMirror...).

  Parameters:

  typeElem - the type element

  typeArgs - the actual type arguments

  Returns:

  the type corresponding to the type element and actual type arguments

  Throws:

  IllegalArgumentException - if too many or too few type arguments are given, or if an inappropriate type argument or type element is provided

• getDeclaredType

  DeclaredType getDeclaredType(DeclaredType containing,
                               TypeElement typeElem,
                               TypeMirror... typeArgs)

  Returns the type corresponding to a type element and actual type arguments, given a containing type of which it is a member. The parameterized type Outer<String>.Inner<Number>, for example, may be constructed by first using getDeclaredType(TypeElement, TypeMirror...) to get the type Outer<String>, and then invoking this method.

  If the containing type is a parameterized type, the number of type arguments must equal the number of typeElem's formal type parameters. If it is not parameterized or if it is null, this method is equivalent to getDeclaredType(typeElem, typeArgs).

  Parameters:

  containing - the containing type, or null if none

  typeElem - the type element

  typeArgs - the actual type arguments

  Returns:

  the type corresponding to the type element and actual type arguments, contained within the given type

  Throws:

  IllegalArgumentException - if too many or too few type arguments are given, or if an inappropriate type argument, type element, or containing type is provided

• asMemberOf

  TypeMirror asMemberOf(DeclaredType containing,
                        Element element)

  Returns the type of an element when that element is viewed as a member of, or otherwise directly contained by, a given type. For example, when viewed as a member of the parameterized type Set<String>, the Set.add method is an ExecutableType whose parameter is of type String.

  Parameters:

  containing - the containing type

  element - the element

  Returns:

  the type of the element as viewed from the containing type

  Throws:

  IllegalArgumentException - if the element is not a valid one for the given type