Module java.base

Package java.lang.constant

Interface MethodTypeDesc

All Superinterfaces:

ConstantDesc, TypeDescriptor, TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

public interface MethodTypeDesc
extends ConstantDesc, TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

A nominal descriptor for a MethodType constant.

API Note:

In the future, if the Java language permits, MethodTypeDesc may become a sealed interface, which would prohibit subclassing except by explicitly permitted types. Non-platform classes should not implement MethodTypeDesc directly.

Since:

12

Nested Class Summary

Nested classes/interfaces declared in interface java.lang.invoke.TypeDescriptor

TypeDescriptor.OfField<F extends TypeDescriptor.OfField<F>>, TypeDescriptor.OfMethod<F extends TypeDescriptor.OfField<F>,M extends TypeDescriptor.OfMethod<F,M>>

Method Summary

Modifier and Type	Method	Description
MethodTypeDesc	changeParameterType(int index, ClassDesc paramType)	Returns a MethodTypeDesc that is identical to this one, except that a single parameter type has been changed to the specified type.
MethodTypeDesc	changeReturnType(ClassDesc returnType)	Returns a MethodTypeDesc that is identical to this one, except with the specified return type.
default String	descriptorString()	Returns the method type descriptor string.
default String	displayDescriptor()	Returns a human-readable descriptor for this method type, using the canonical names for parameter and return types.
MethodTypeDesc	dropParameterTypes(int start, int end)	Returns a MethodTypeDesc that is identical to this one, except that a range of parameter types have been removed.
boolean	equals(Object o)	Compares the specified object with this descriptor for equality.
MethodTypeDesc	insertParameterTypes(int pos, ClassDesc... paramTypes)	Returns a MethodTypeDesc that is identical to this one, except that a range of additional parameter types have been inserted.
static MethodTypeDesc	of(ClassDesc returnDesc, ClassDesc... paramDescs)	Returns a MethodTypeDesc given the return type and parameter types.
static MethodTypeDesc	ofDescriptor(String descriptor)	Creates a MethodTypeDesc given a method descriptor string.
ClassDesc[]	parameterArray()	Returns the parameter types as an array.
int	parameterCount()	Returns the number of parameters of the method type described by this MethodTypeDesc.
List<ClassDesc>	parameterList()	Returns the parameter types as an immutable List.
ClassDesc	parameterType(int index)	Returns the parameter type of the index'th parameter of the method type described by this MethodTypeDesc.
ClassDesc	returnType()	Gets the return type of the method type described by this MethodTypeDesc.

Methods declared in interface java.lang.constant.ConstantDesc

resolveConstantDesc

Method Details

ofDescriptor

static MethodTypeDesc ofDescriptor(String descriptor)

Creates a MethodTypeDesc given a method descriptor string.

Parameters:

descriptor - a method descriptor string

Returns:

a MethodTypeDesc describing the desired method type

Throws:

NullPointerException - if the argument is null

IllegalArgumentException - if the descriptor string is not a valid method descriptor

See Java Virtual Machine Specification:

4.3.3 Method Descriptors

of

static MethodTypeDesc of(ClassDesc returnDesc,
 ClassDesc... paramDescs)

Returns a MethodTypeDesc given the return type and parameter types.

Parameters:

returnDesc - a ClassDesc describing the return type

paramDescs - ClassDescs describing the argument types

Returns:

a MethodTypeDesc describing the desired method type

Throws:

NullPointerException - if any argument or its contents are null

IllegalArgumentException - if any element of paramDescs is a ClassDesc for void

returnType

ClassDesc returnType()

Gets the return type of the method type described by this MethodTypeDesc.

Specified by:

returnType in interface TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

Returns:

a ClassDesc describing the return type of the method type

parameterCount

int parameterCount()

Returns the number of parameters of the method type described by this MethodTypeDesc.

Specified by:

parameterCount in interface TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

Returns:

the number of parameters

parameterType

ClassDesc parameterType(int index)

Returns the parameter type of the index'th parameter of the method type described by this MethodTypeDesc.

Specified by:

parameterType in interface TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

Parameters:

index - the index of the parameter to retrieve

Returns:

a ClassDesc describing the desired parameter type

Throws:

IndexOutOfBoundsException - if the index is outside the half-open range {[0, parameterCount())}

parameterList

List<ClassDesc> parameterList()

Returns the parameter types as an immutable List.

Specified by:

parameterList in interface TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

Returns:

a List of ClassDesc describing the parameter types

parameterArray

ClassDesc[] parameterArray()

Returns the parameter types as an array.

Specified by:

parameterArray in interface TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

Returns:

an array of ClassDesc describing the parameter types

changeReturnType

MethodTypeDesc changeReturnType(ClassDesc returnType)

Returns a MethodTypeDesc that is identical to this one, except with the specified return type.

Specified by:

changeReturnType in interface TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

Parameters:

returnType - a ClassDesc describing the new return type

Returns:

a MethodTypeDesc describing the desired method type

Throws:

NullPointerException - if the argument is null

changeParameterType

MethodTypeDesc changeParameterType(int index,
 ClassDesc paramType)

Returns a MethodTypeDesc that is identical to this one, except that a single parameter type has been changed to the specified type.

Specified by:

changeParameterType in interface TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

Parameters:

index - the index of the parameter to change

paramType - a ClassDesc describing the new parameter type

Returns:

a MethodTypeDesc describing the desired method type

Throws:

NullPointerException - if any argument is null

IndexOutOfBoundsException - if the index is outside the half-open range {[0, parameterCount)}

dropParameterTypes

MethodTypeDesc dropParameterTypes(int start,
 int end)

Returns a MethodTypeDesc that is identical to this one, except that a range of parameter types have been removed.

Specified by:

dropParameterTypes in interface TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

Parameters:

start - the index of the first parameter to remove

end - the index after the last parameter to remove

Returns:

a MethodTypeDesc describing the desired method type

Throws:

IndexOutOfBoundsException - if start is outside the half-open range [0, parameterCount), or end is outside the closed range [0, parameterCount], or if start > end

insertParameterTypes

MethodTypeDesc insertParameterTypes(int pos,
 ClassDesc... paramTypes)

Returns a MethodTypeDesc that is identical to this one, except that a range of additional parameter types have been inserted.

Specified by:

insertParameterTypes in interface TypeDescriptor.OfMethod<ClassDesc,MethodTypeDesc>

Parameters:

pos - the index at which to insert the first inserted parameter

paramTypes - ClassDescs describing the new parameter types to insert

Returns:

a MethodTypeDesc describing the desired method type

Throws:

NullPointerException - if any argument or its contents are null

IndexOutOfBoundsException - if pos is outside the closed range {[0, parameterCount]}

IllegalArgumentException - if any element of paramTypes is a ClassDesc for void

descriptorString

default String descriptorString()

Returns the method type descriptor string.

Specified by:

descriptorString in interface TypeDescriptor

Returns:

the method type descriptor string

See Java Virtual Machine Specification:

4.3.3 Method Descriptors

displayDescriptor

default String displayDescriptor()

Returns a human-readable descriptor for this method type, using the canonical names for parameter and return types.

Returns:

the human-readable descriptor for this method type

equals

boolean equals(Object o)

Compares the specified object with this descriptor for equality. Returns true if and only if the specified object is also a MethodTypeDesc both have the same arity, their return types are equal, and each pair of corresponding parameter types are equal.

Overrides:

equals in class Object

Parameters:

o - the other object

Returns:

whether this descriptor is equal to the other object

See Also:

Object.hashCode(), HashMap