org.dynalang.dynalink.support

Class Lookup

java.lang.Object

org.dynalang.dynalink.support.Lookup

public class Lookup
extends Object

A wrapper around MethodHandles.Lookup that masks checked exceptions in those cases when you're looking up methods within your own codebase (therefore it is an error if they are not present).

Author:

Attila Szegedi

Field Summary

Fields

Modifier and Type	Field and Description
static Lookup	PUBLIC A canonical Lookup object that wraps MethodHandles.publicLookup().

Constructor Summary

Constructors

Constructor and Description
Lookup(java.lang.invoke.MethodHandles.Lookup lookup) Creates a new instance, bound to an instance of MethodHandles.Lookup.

Method Summary

Modifier and Type	Method and Description
java.lang.invoke.MethodHandle	findGetter(Class<?> refc, String name, Class<?> type) Performs a MethodHandles.Lookup.findGetter(Class, String, Class), converting any encountered IllegalAccessException into an IllegalAccessError and NoSuchFieldException into a NoSuchFieldError.
static java.lang.invoke.MethodHandle	findOwnSpecial(java.lang.invoke.MethodHandles.Lookup lookup, String name, Class<?> rtype, Class<?>... ptypes) Given a lookup, finds using findSpecial(Class, String, MethodType) a method on that lookup's class.
java.lang.invoke.MethodHandle	findOwnSpecial(String name, Class<?> rtype, Class<?>... ptypes) Finds using findSpecial(Class, String, MethodType) a method on that lookup's class.
static java.lang.invoke.MethodHandle	findOwnStatic(java.lang.invoke.MethodHandles.Lookup lookup, String name, Class<?> rtype, Class<?>... ptypes) Given a lookup, finds using findStatic(Class, String, MethodType) a method on that lookup's class.
java.lang.invoke.MethodHandle	findOwnStatic(String name, Class<?> rtype, Class<?>... ptypes) Finds using findStatic(Class, String, MethodType) a method on that lookup's class.
java.lang.invoke.MethodHandle	findSpecial(Class<?> declaringClass, String name, java.lang.invoke.MethodType type) Performs a findSpecial on the underlying lookup, except for the backport where it rather uses unreflect.
java.lang.invoke.MethodHandle	findStatic(Class<?> declaringClass, String name, java.lang.invoke.MethodType type) Performs a findStatic on the underlying lookup.
java.lang.invoke.MethodHandle	findVirtual(Class<?> declaringClass, String name, java.lang.invoke.MethodType type) Performs a findVirtual on the underlying lookup.
java.lang.invoke.MethodHandle	unreflect(Method m) Performs a MethodHandles.Lookup.unreflect(Method), converting any encountered IllegalAccessException into an IllegalAccessError.
java.lang.invoke.MethodHandle	unreflectConstructor(Constructor<?> c) Performs a MethodHandles.Lookup.unreflectConstructor(Constructor), converting any encountered IllegalAccessException into an IllegalAccessError.
java.lang.invoke.MethodHandle	unreflectGetter(Field f) Performs a MethodHandles.Lookup.unreflectGetter(Field), converting any encountered IllegalAccessException into an IllegalAccessError.
java.lang.invoke.MethodHandle	unreflectSetter(Field f) Performs a MethodHandles.Lookup.unreflectSetter(Field), converting any encountered IllegalAccessException into an IllegalAccessError.

Methods inherited from class java.lang.Object

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

Field Detail

PUBLIC

public static final Lookup PUBLIC

A canonical Lookup object that wraps MethodHandles.publicLookup().

Constructor Detail

Lookup

public Lookup(java.lang.invoke.MethodHandles.Lookup lookup)

Creates a new instance, bound to an instance of MethodHandles.Lookup.

Parameters:

lookup - the MethodHandles.Lookup it delegates to.

Method Detail

unreflect

public java.lang.invoke.MethodHandle unreflect(Method m)

Performs a MethodHandles.Lookup.unreflect(Method), converting any encountered IllegalAccessException into an IllegalAccessError.

Parameters:

m - the method to unreflect

Returns:

the unreflected method handle.

unreflectGetter

public java.lang.invoke.MethodHandle unreflectGetter(Field f)

Performs a MethodHandles.Lookup.unreflectGetter(Field), converting any encountered IllegalAccessException into an IllegalAccessError.

Parameters:

f - the field for which a getter is unreflected

Returns:

the unreflected field getter handle.

findGetter

public java.lang.invoke.MethodHandle findGetter(Class<?> refc,
                                       String name,
                                       Class<?> type)

Performs a MethodHandles.Lookup.findGetter(Class, String, Class), converting any encountered IllegalAccessException into an IllegalAccessError and NoSuchFieldException into a NoSuchFieldError.

Parameters:

refc - the class declaring the field

name - the name of the field

type - the type of the field

Returns:

the unreflected field getter handle.

Throws:

IllegalAccessError - if the field is inaccessible.

NoSuchFieldError - if the field does not exist.

unreflectSetter

public java.lang.invoke.MethodHandle unreflectSetter(Field f)

Performs a MethodHandles.Lookup.unreflectSetter(Field), converting any encountered IllegalAccessException into an IllegalAccessError.

Parameters:

f - the field for which a setter is unreflected

Returns:

the unreflected field setter handle.

unreflectConstructor

public java.lang.invoke.MethodHandle unreflectConstructor(Constructor<?> c)

Performs a MethodHandles.Lookup.unreflectConstructor(Constructor), converting any encountered IllegalAccessException into an IllegalAccessError.

Parameters:

c - the constructor to unreflect

Returns:

the unreflected constructor handle.

findSpecial

public java.lang.invoke.MethodHandle findSpecial(Class<?> declaringClass,
                                        String name,
                                        java.lang.invoke.MethodType type)

Performs a findSpecial on the underlying lookup, except for the backport where it rather uses unreflect. Converts any encountered IllegalAccessException into an IllegalAccessError and a NoSuchMethodException into a NoSuchMethodError.

Parameters:

declaringClass - class declaring the method

name - the name of the method

type - the type of the method

Returns:

a method handle for the method

Throws:

IllegalAccessError - if the method is inaccessible.

NoSuchMethodError - if the method does not exist.

findStatic

public java.lang.invoke.MethodHandle findStatic(Class<?> declaringClass,
                                       String name,
                                       java.lang.invoke.MethodType type)

Performs a findStatic on the underlying lookup. Converts any encountered IllegalAccessException into an IllegalAccessError and a NoSuchMethodException into a NoSuchMethodError.

Parameters:

declaringClass - class declaring the method

name - the name of the method

type - the type of the method

Returns:

a method handle for the method

Throws:

IllegalAccessError - if the method is inaccessible.

NoSuchMethodError - if the method does not exist.

findVirtual

public java.lang.invoke.MethodHandle findVirtual(Class<?> declaringClass,
                                        String name,
                                        java.lang.invoke.MethodType type)

Performs a findVirtual on the underlying lookup. Converts any encountered IllegalAccessException into an IllegalAccessError and a NoSuchMethodException into a NoSuchMethodError.

Parameters:

declaringClass - class declaring the method

name - the name of the method

type - the type of the method

Returns:

a method handle for the method

Throws:

IllegalAccessError - if the method is inaccessible.

NoSuchMethodError - if the method does not exist.

findOwnSpecial

public static java.lang.invoke.MethodHandle findOwnSpecial(java.lang.invoke.MethodHandles.Lookup lookup,
                                           String name,
                                           Class<?> rtype,
                                           Class<?>... ptypes)

Given a lookup, finds using findSpecial(Class, String, MethodType) a method on that lookup's class. Useful in classes' code for convenient linking to their own privates.

Parameters:

lookup - the lookup for the class

name - the name of the method

rtype - the return type of the method

ptypes - the parameter types of the method

Returns:

the method handle for the method

findOwnSpecial

public java.lang.invoke.MethodHandle findOwnSpecial(String name,
                                           Class<?> rtype,
                                           Class<?>... ptypes)

Finds using findSpecial(Class, String, MethodType) a method on that lookup's class. Useful in classes' code for convenient linking to their own privates. It's easier to use than findSpecial in that you can just list the parameter types, and don't have to specify lookup class.

Parameters:

name - the name of the method

rtype - the return type of the method

ptypes - the parameter types of the method

Returns:

the method handle for the method

findOwnStatic

public static java.lang.invoke.MethodHandle findOwnStatic(java.lang.invoke.MethodHandles.Lookup lookup,
                                          String name,
                                          Class<?> rtype,
                                          Class<?>... ptypes)

Given a lookup, finds using findStatic(Class, String, MethodType) a method on that lookup's class. Useful in classes' code for convenient linking to their own privates. It's easier to use than findStatic in that you can just list the parameter types, and don't have to specify lookup class.

Parameters:

lookup - the lookup for the class

name - the name of the method

rtype - the return type of the method

ptypes - the parameter types of the method

Returns:

the method handle for the method

findOwnStatic

public java.lang.invoke.MethodHandle findOwnStatic(String name,
                                          Class<?> rtype,
                                          Class<?>... ptypes)

Finds using findStatic(Class, String, MethodType) a method on that lookup's class. Useful in classes' code for convenient linking to their own privates. It's easier to use than findStatic in that you can just list the parameter types, and don't have to specify lookup class.

Parameters:

name - the name of the method

rtype - the return type of the method

ptypes - the parameter types of the method

Returns:

the method handle for the method