net.bytebuddy.dynamic.loading

Class ClassLoadingStrategy.UsingLookup

java.lang.Object

net.bytebuddy.dynamic.loading.ClassLoadingStrategy.UsingLookup

All Implemented Interfaces:

ClassLoadingStrategy<ClassLoader>

Enclosing interface:

ClassLoadingStrategy<T extends ClassLoader>

@HashCodeAndEqualsPlugin.Enhance
public static class ClassLoadingStrategy.UsingLookup
extends Object
implements ClassLoadingStrategy<ClassLoader>

A class loading strategy that uses a java.lang.invoke.MethodHandles$Lookup instance for defining types. A lookup instance can define types only in the same class loader and in the same package as the type within which it was created. The supplied lookup must have package privileges, i.e. it must not be a public lookup.

Nested Class Summary

Nested classes/interfaces inherited from interface net.bytebuddy.dynamic.loading.ClassLoadingStrategy

ClassLoadingStrategy.Configurable<S extends ClassLoader>, ClassLoadingStrategy.Default, ClassLoadingStrategy.ForBootstrapInjection, ClassLoadingStrategy.ForJnaInjection, ClassLoadingStrategy.ForUnsafeInjection, ClassLoadingStrategy.UsingLookup

Field Summary

Fields inherited from interface net.bytebuddy.dynamic.loading.ClassLoadingStrategy

BOOTSTRAP_LOADER, NO_PROTECTION_DOMAIN

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	UsingLookup(ClassInjector classInjector) Creates a new class loading strategy that uses a lookup type.

Method Summary

Modifier and Type	Method and Description
Map<TypeDescription,Class<?>>	load(ClassLoader classLoader, Map<TypeDescription,byte[]> types) Loads a given collection of classes given their binary representation.
static ClassLoadingStrategy<ClassLoader>	of(Object lookup) Creates a new class loading strategy that uses a java.lang.invoke.MethodHandles$Lookup instance.
static ClassLoadingStrategy<ClassLoader>	withFallback(Callable<?> lookup) Resolves a class loading strategy using a lookup if available on the current JVM.
static ClassLoadingStrategy<ClassLoader>	withFallback(Callable<?> lookup, boolean wrapper) Resolves a class loading strategy using a lookup if available on the current JVM.

Methods inherited from class java.lang.Object

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

Constructor Detail

UsingLookup

protected UsingLookup(ClassInjector classInjector)

Creates a new class loading strategy that uses a lookup type.

Parameters:

classInjector - The class injector to use.

Method Detail

of

public static ClassLoadingStrategy<ClassLoader> of(Object lookup)

Creates a new class loading strategy that uses a java.lang.invoke.MethodHandles$Lookup instance.

Parameters:

lookup - The lookup instance to use for defining new types.

Returns:

A suitable class loading strategy.

withFallback

public static ClassLoadingStrategy<ClassLoader> withFallback(Callable<?> lookup)

Resolves a class loading strategy using a lookup if available on the current JVM. If the current JVM supports method handles lookups, a lookup instance will be used. Alternatively, unsafe class definition is used, if supported. If neither strategy is supported, an exception is thrown. A common use case would be calling this method as in ClassLoadingStrategy.UsingLookup.withFallback(MethodHandles::lookup). Note that the invocation of MethodHandles.lookup() is call site sensitive such that it cannot be invoked within Byte Buddy what requires this external invocation.

Parameters:

lookup - A resolver for a lookup instance if the current JVM allows for lookup-based class injection.

Returns:

An appropriate class loading strategy for the current JVM that uses a method handles lookup if available.

withFallback

public static ClassLoadingStrategy<ClassLoader> withFallback(Callable<?> lookup,
                                                             boolean wrapper)

Resolves a class loading strategy using a lookup if available on the current JVM. If the current JVM supports method handles lookups, a lookup instance will be used. Alternatively, unsafe class definition is used, if supported. If neither strategy is supported, an exception is thrown. A common use case would be calling this method as in ClassLoadingStrategy.UsingLookup.withFallback(MethodHandles::lookup). Note that the invocation of MethodHandles.lookup() is call site sensitive such that it cannot be invoked within Byte Buddy what requires this external invocation.

Parameters:

lookup - A resolver for a lookup instance if the current JVM allows for lookup-based class injection.

wrapper - true if a ClassLoadingStrategy.Default.WRAPPER strategy should be used as a fallback in case that no injection strategy is available.

Returns:

An appropriate class loading strategy for the current JVM that uses a method handles lookup if available.

load

public Map<TypeDescription,Class<?>> load(@MaybeNull
                                          ClassLoader classLoader,
                                          Map<TypeDescription,byte[]> types)

Loads a given collection of classes given their binary representation.

Specified by:

load in interface ClassLoadingStrategy<ClassLoader>

Parameters:

classLoader - The class loader to used for loading the classes.

types - Byte array representations of the types to be loaded mapped by their descriptions, where an iteration order defines an order in which they are supposed to be loaded, if relevant.

Returns:

A collection of the loaded classes which will be initialized in the iteration order of the returned collection.