org.opencypher.tools

Class Reflection

java.lang.Object

org.opencypher.tools.Reflection

public class Reflection
extends Object

Utilities for working with Java reflection.

Constructor Summary

Constructors

Constructor and Description
Reflection()

Method Summary

Modifier and Type	Method and Description
static MethodHandle	defaultInvoker(Method method) Returns a method handle that invoke a default method of an interface.
static <T> Method	implementation(T instance, Class<T> base, String methodName) Find that method of a given instance that implements the specified abstract method of a given base class.
static Object	invoke(MethodHandle method, Object target) Invoke the given method handle with the specified single argument.
static <T> T	lambda(MethodHandles.Lookup caller, Class<T> type, MethodHandle target, TypedArgument... arguments) Implement a functional interface by a MethodHandle in the same way that a lambda would.
static Class<?>	lambdaClass(Serializable lambda) Get the class where the method of a (serializable) lambda is implemented.
static String	lambdaImplMethodName(Serializable lambda) Get the name of the method used to implement a (serializable) lambda.
static String	lambdaParameterName(Serializable lambda) Get the parameter name of a (serializable) lambda with a single parameter.
static MethodHandle	methodHandle(MethodHandles.Lookup lookup, Serializable lambda) Get a method handle to the underlying method that implements a given (serializable) lambda.
static String	pathOf(Class<?> cls) Get the location in the classpath from where the given class is loaded.

Methods inherited from class java.lang.Object

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

Constructor Detail

Reflection

public Reflection()

Method Detail

lambdaParameterName

public static String lambdaParameterName(Serializable lambda)

Get the parameter name of a (serializable) lambda with a single parameter.

Getting the parameter requires the source to be compiled with the -parameters flag passed to javac and JDK 1.8.0_60 or newer.

Parameters:

lambda - the (serializable) lambda to get the parameter name from.

Returns:

the name of the sole parameter of the lambda.

lambda

public static <T> T lambda(MethodHandles.Lookup caller,
                           Class<T> type,
                           MethodHandle target,
                           TypedArgument... arguments)

Implement a functional interface by a MethodHandle in the same way that a lambda would.

Type Parameters:

T - the type of the functional interface.

Parameters:

caller - the lookup context of the caller.

type - the functional interface to implement.

target - the method handle to implement the method of the functional interface.

arguments - extra arguments to be passed to the target method handle, in addition to the arguments of the implemented method.

Returns:

an implementation of the functional interface based on the supplied method handle.

defaultInvoker

public static MethodHandle defaultInvoker(Method method)

Returns a method handle that invoke a default method of an interface.

Parameters:

method - the (default) method to get a method handle for.

Returns:

a method handle that invokes the specific default method.

invoke

public static Object invoke(MethodHandle method,
                            Object target)

Invoke the given method handle with the specified single argument. Handles the exceptions declared by MethodHandle allowing this method to be used in a context where no checked exceptions may be thrown.

Parameters:

method - the method handle to invoke.

target - the argument to pass to the method.

Returns:

the result of invoking the method.

lambdaClass

public static Class<?> lambdaClass(Serializable lambda)

Get the class where the method of a (serializable) lambda is implemented.

Parameters:

lambda - the (serializable) lambda to get the implementing class of.

Returns:

the class where the (serializable) lambda is implemented.

pathOf

public static String pathOf(Class<?> cls)

Get the location in the classpath from where the given class is loaded.

Parameters:

cls - the class to find the classpath location of.

Returns:

the classpath location of the given class.

lambdaImplMethodName

public static String lambdaImplMethodName(Serializable lambda)

Get the name of the method used to implement a (serializable) lambda. This is mostly useful for lambdas that are implemented by a method reference.

Parameters:

lambda - the lambda to get the implementing method name of.

Returns:

the name of the method that implements the given (serializable) lambda.

methodHandle

public static MethodHandle methodHandle(MethodHandles.Lookup lookup,
                                        Serializable lambda)

Get a method handle to the underlying method that implements a given (serializable) lambda.

Parameters:

lookup - a context that has access to looking up the target method.

lambda - the (serializable) lambda to find the implementing method of.

Returns:

a method handle to the implementing method of the given (serializable) lambda.

implementation

public static <T> Method implementation(T instance,
                                        Class<T> base,
                                        String methodName)

Find that method of a given instance that implements the specified abstract method of a given base class.

This is useful for finding the actual type that implements a type parameter of the base class.

Type Parameters:

T - the base type of the instance (the type of the base class).

Parameters:

instance - the instance to find the implementation method of.

base - the base class that declares the abstract method in question.

methodName - the name of the abstract method.

Returns:

the method that implements the abstract method of the base class.