com.fluxtion.runtime.annotations.builder.Inject Maven / Gradle / Ivy
/*
* Copyright (C) 2018 2024 gregory higgins.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* .
*/
package com.fluxtion.runtime.annotations.builder;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Marks a reference as an injection point for an instance. An injected instance
* is created using a NodeFactory, see Fluxtion builder module.
*
*
* If no NodeFactory is implemented for this type then a zero argument
* constructor will be used to inject the reference. Properties of the injected
* instance will be set using the configuration map, where keys are the member
* properties of the class.
*
* Once an injected instance has been created it will be added to the SEP
* execution graph as if a user had added the node manually. The injected node
* will be inspected for annotations and processed by the Fluxtion Static Event
* Compiler. New injected instances are recursively inspected until no more
* injected instances are added to the execution graph. The recursive addition
* of injected instances allows arbitrarily complex execution graphs be created
* with a single {@literal @}Inject annotation.
*
* Injected references can be configured using {@link ConfigVariable} and
* {@link Config} annotations.
*
* @author Greg Higgins
* @see Config
* @see ConfigVariable
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface Inject {
/**
* Create and inject only a single instance in the generated SEP if true.
*
* @return singleton flag
*/
boolean singleton() default false;
/**
* The name of the singleton if the singleton = true
*
* @return singleton name
*/
String singletonName() default "";
/**
* The name of the NodeFactory.
*
* @return the NodeFactory name that will inject the instance into the graph
*/
String factoryName() default "";
/**
* The name of the NodeFactory read from a variable in the annotated class.
*
* @return the NodeFactory name that will inject the instance into the graph
*/
String factoryVariableName() default "";
/**
* Specify the qualifier of the instance to inject if using runtime instance injection with:
* {@link com.fluxtion.runtime.StaticEventProcessor#injectNamedInstance(Object, String)}
*
* @return the runtime instance qualifer
*/
String instanceName() default "";
/**
* Specify the qualifier of the instance to inject if using runtime instance injection with,
* read from a variable in the annotated class.
*
* {@link com.fluxtion.runtime.StaticEventProcessor#injectNamedInstance(Object, String)}
*
* @return the runtime instance qualifer
*/
String instanceVariableName() default "";
}