com.google.inject.spi.ModuleAnnotatedMethodScanner Maven / Gradle / Ivy
/*
* Copyright (C) 2015 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.inject.spi;
import com.google.inject.Binder;
import com.google.inject.Key;
import java.lang.annotation.Annotation;
import java.util.Set;
/**
* Allows extensions to scan modules for annotated methods and bind those methods as providers,
* similar to {@code @Provides} methods.
*
* @since 4.0
*/
public abstract class ModuleAnnotatedMethodScanner {
/**
* Returns the annotations this should scan for. Every method in the module that has one of these
* annotations will create a Provider binding, with the return value of the binding being what's
* provided and the parameters of the method being dependencies of the provider.
*/
public abstract Set> annotationClasses();
/**
* Prepares a method for binding. This {@code key} parameter is the key discovered from looking at
* the binding annotation and return value of the method. Implementations can modify the key to
* instead bind to another key. For example, Multibinder may want to change
* {@code @ProvidesIntoSet String provideFoo()} to bind into a unique Key within the multibinder
* instead of binding {@code String}.
*
* The injection point and annotation are provided in case the implementation wants to set the
* key based on the property of the annotation or if any additional preparation is needed for any
* of the dependencies. The annotation is guaranteed to be an instance of one the classes returned
* by {@link #annotationClasses}.
*
*
Returning null will cause Guice to skip this method, so that it is not bound to any key.
*
*
If {@code injectionPoint} represents an {@code abstract} method, {@code null} must be
* returned from this method. This scanner can use {@code binder} to bind alternative bindings in
* place of the abstract method.
*/
public abstract Key prepareMethod(
Binder binder, Annotation annotation, Key key, InjectionPoint injectionPoint);
}