ch.jalu.injector.handlers.instantiation

Class StandardInjectionProvider

java.lang.Object

ch.jalu.injector.handlers.instantiation.DirectInstantiationProvider

ch.jalu.injector.handlers.instantiation.StandardInjectionProvider

All Implemented Interfaces:

Handler

Direct Known Subclasses:

DefaultInjectionProvider

public class StandardInjectionProvider
extends DirectInstantiationProvider

Provider of Resolution objects that roughly follows the documentation as given in Inject. The following is a summary of the instantiation's behavior and its deviations.

If available, the constructor with @Inject is used. Multiple @Inject constructors results in an exception being thrown. Otherwise, if there is only one constructor, of public visibility taking no arguments, it is taken. For private classes (inner classes), a sole no-args constructor is also considered. Finally, the no-args constructor of any visibility is taken if it belongs to a class that has @Inject fields. In this case, the no-args constructor is not required to be the only constructor of the class.

Fields with @Inject are injected. They may be static (not recommended). If a final field is annotated with @Inject, an exception is thrown.

Method injection is not supported. Consequently, if a method with @Inject is found on the class or any of its parents, an exception is thrown.

NoMethodScan and NoFieldScan are respected.

Constructor Summary

Constructors

Constructor and Description
StandardInjectionProvider()

Method Summary

Modifier and Type	Method and Description
protected List<Field>	getFieldsToInject(Class<?> clazz) Returns the fields in the class and its parents that should be injected.
protected <T> Constructor<T>	getInjectionConstructor(Class<T> clazz) Returns the constructor to be used for injection.
<T> Resolution<T>	safeGet(Class<T> clazz) Gets the instantiation for the class or null if unavailable.
protected void	validateInjection(Class<?> clazz, Constructor<?> constructor, List<Field> fields) Assures that the class and the members relevant for the instantiation form a valid combination.

Methods inherited from class ch.jalu.injector.handlers.instantiation.DirectInstantiationProvider

resolve

Methods inherited from class java.lang.Object

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

Methods inherited from interface ch.jalu.injector.handlers.Handler

onAnnotation, onProvider, onProviderClass, postProcess

Constructor Detail

StandardInjectionProvider

public StandardInjectionProvider()

Method Detail

safeGet

public <T> Resolution<T> safeGet(Class<T> clazz)

Description copied from class: DirectInstantiationProvider

Gets the instantiation for the class or null if unavailable. This method is only called with classes which can be instantiated.

Specified by:

safeGet in class DirectInstantiationProvider

Type Parameters:

T - the class' type

Parameters:

clazz - the class to process

Returns:

the instantiation, or null if not applicable

getInjectionConstructor

@Nullable
protected <T> Constructor<T> getInjectionConstructor(Class<T> clazz)

Returns the constructor to be used for injection. Throws an exception if there are multiple @Inject constructors.

Type Parameters:

T - the class' type

Parameters:

clazz - the class to process

Returns:

the constructor, or null if there is no constructor suitable for injection

getFieldsToInject

protected List<Field> getFieldsToInject(Class<?> clazz)

Returns the fields in the class and its parents that should be injected.

Parameters:

clazz - the class to process

Returns:

the fields to inject

validateInjection

protected void validateInjection(Class<?> clazz,
                                 Constructor<?> constructor,
                                 List<Field> fields)

Assures that the class and the members relevant for the instantiation form a valid combination.

Parameters:

clazz - the class to instantiate

constructor - the constructor to instantiate with

fields - the fields to inject