net.bytebuddy.instrumentation

Interface Instrumentation

All Known Subinterfaces:

FieldAccessor.AssignerConfigurable, FieldAccessor.FieldDefinable, FieldAccessor.OwnerTypeLocatable, FixedValue.AssignerConfigurable

All Known Implementing Classes:

ExceptionMethod, FieldAccessor, FieldAccessor.ForBeanProperty, FieldAccessor.ForNamedField, FixedValue, FixedValue.ForPoolValue, FixedValue.ForStaticField, Instrumentation.Compound, Instrumentation.ForAbstractMethod, InvocationHandlerAdapter, MethodDelegation, StubMethod, SuperMethodCall

public interface Instrumentation

An instrumentation is responsible for implementing (or not implementing) methods of a dynamically created type. An instrumentation is applied in two stages:

1. The instrumentation is able to prepare an instrumented type by adding fields and/or helper methods that are required for the methods implemented by this instrumentation. Furthermore, TypeInitializers can be registered for an instrumented type.
2. An instrumentation is required to supply a byte code appender that is responsible for providing the byte code to the instrumented methods that were delegated to this instrumentation. This byte code appender will also be responsible for providing implementations for the methods added in step 1.

An instrumentation implementation should provide meaningful implementations Object.equals(Object) and Object.hashCode() if it wants to avoid to be used twice within the creation of a dynamic type. For two equal instrumentation implementations only one will be applied on the creation of a dynamic type.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Instrumentation.Compound A compound instrumentation that allows to combine several instrumentations.
static interface	Instrumentation.Context The context for an instrumentation application.
static class	Instrumentation.ForAbstractMethod An instrumentation for an abstract method that does not append any code and will throw an exception if it is attempted to be composed with other methods that do provide an implementation.

Method Summary

Modifier and Type	Method and Description
ByteCodeAppender	appender(TypeDescription instrumentedType) Creates a byte code appender that determines the implementation of the instrumented type's methods.
InstrumentedType	prepare(InstrumentedType instrumentedType) During the preparation phase of an instrumentation, implementations are eligible to adding fields or methods to the currently instrumented type.

Method Detail

prepare

InstrumentedType prepare(InstrumentedType instrumentedType)

During the preparation phase of an instrumentation, implementations are eligible to adding fields or methods to the currently instrumented type. All methods that are added by this instrumentation are required to be implemented by the ByteCodeAppender that is emitted on the call to appender(net.bytebuddy.instrumentation.type.TypeDescription) call. On this method call, type initializers can also be added to the instrumented type.

Parameters:

instrumentedType - The instrumented type that is the basis of the ongoing instrumentation.

Returns:

The instrumented type with any applied changes, if any.

appender

ByteCodeAppender appender(TypeDescription instrumentedType)

Creates a byte code appender that determines the implementation of the instrumented type's methods.

Parameters:

instrumentedType - The instrumented type that is to be created.

Returns:

A byte code appender for implementing methods delegated to this instrumentation. This byte code appender is also responsible for handling methods that were added by this instrumentation on the call to prepare(net.bytebuddy.instrumentation.type.InstrumentedType).