Module org.elasticsearch.server

Package org.elasticsearch.injection

Class Injector

java.lang.Object

org.elasticsearch.injection.Injector

public final class Injector
extends Object

The main object for dependency injection.

Allows the user to specify the requirements, then call inject(java.util.Collection<? extends java.lang.Class<?>>) to create an object plus all its dependencies.

Implementation note: this class itself contains logic for specifying the injection requirements; the actual injection operations are performed in other classes like Planner and PlanInterpreter,

Method Summary

Modifier and Type	Method	Description
Injector	addClass(Class<?> classToProcess)	Instructs the injector to instantiate classToProcess in accordance with whatever annotations may be present on that class.
Injector	addClasses(Collection<Class<?>> classesToProcess)	Equivalent to multiple chained calls to addClass(java.lang.Class<?>).
<T> Injector	addInstance(Class<? super T> type, T object)	Indicates that object is to be injected for parameters of type type.
<T> Injector	addInstance(Object object)	Equivalent to addInstance(object.getClass(), object).
Injector	addInstances(Collection<?> objects)	Equivalent to multiple calls to addInstance(Object).
static Injector	create()
Map<Class<?>,Object>	inject(Collection<? extends Class<?>> resultTypes)	Main entry point.

Methods inherited from class java.lang.Object

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

Method Details

create

public static Injector create()

addClass

public Injector addClass(Class<?> classToProcess)

Instructs the injector to instantiate classToProcess in accordance with whatever annotations may be present on that class.

There are only three ways the injector can find out that it must instantiate some class:

1. This method
2. The parameter passed to inject(java.util.Collection<? extends java.lang.Class<?>>)
3. A constructor parameter of some other class being instantiated, having exactly the right class (not a supertype)

Returns:

this

addClasses

public Injector addClasses(Collection<Class<?>> classesToProcess)

Equivalent to multiple chained calls to addClass(java.lang.Class<?>).

addInstance

public <T> Injector addInstance(Object object)

Equivalent to addInstance(object.getClass(), object).

addInstances

public Injector addInstances(Collection<?> objects)

Equivalent to multiple calls to addInstance(Object).

addInstance

public <T> Injector addInstance(Class<? super T> type,
 T object)

Indicates that object is to be injected for parameters of type type. The given object is treated as though it had been instantiated by the injector.

inject

public Map<Class<?>,Object> inject(Collection<? extends Class<?>> resultTypes)

Main entry point. Causes objects to be constructed.

Returns:

Map whose keys are all the requested resultTypes and whose values are all the instances of those types.