Package com.ultikits.ultitools.context

Class SimpleContainer

java.lang.Object

com.ultikits.ultitools.context.SimpleContainer

@Internal
public class SimpleContainer
extends Object

Simple dependency injection container to replace Spring ApplicationContext.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	SimpleContainer.BeanScope

Field Summary

Fields

Modifier and Type	Field	Description
private AopProxyResolver	aopProxyResolver	Resolves which class to instantiate for a bean.
private final Map<String,BeanDefinition>	beanDefinitions
private final List<BeanPostProcessor>	beanPostProcessors
private final Map<String,SimpleContainer.BeanScope>	beanScopes
private final Map<String,Class<?>>	beanTypes
private ClassLoader	classLoader
private final Set<String>	currentlyCreating
private String	displayName
private final Map<String,Object>	earlySingletonObjects
private boolean	isStarted
private static final Logger	LOGGER
private SimpleContainer	parent
private final Map<Class<?>,Object>	resolvedTypeCache
private final Map<String,Supplier<Object>>	singletonFactories
private final Map<String,Object>	singletonObjects
private final Map<String,Object>	singletons
private final Map<String,Supplier<Object>>	suppliers
private final Map<String,Class<?>>	supplierTypes
private final Map<Class<?>,Object>	typeMappings
private final Map<Class<?>,Supplier<Object>>	typeSuppliers
private final Map<String,Throwable>	unresolvableBeans

Constructor Summary

Constructors

Constructor	Description
SimpleContainer()
SimpleContainer(SimpleContainer parent)

Method Summary

Modifier and Type	Method	Description
void	addBeanPostProcessor(BeanPostProcessor processor)	Add bean post processor.
protected void	addSingleton(String beanName, Object singletonObject)	Add a fully initialized singleton to level 1 cache.
protected void	addSingletonFactory(String beanName, Supplier<Object> singletonFactory)	Add a singleton factory to level 3 cache for early reference support.
void	close()	Close the container.
boolean	containsBean(String name)	Check if container contains bean.
private Object	createBean(String name, BeanDefinition definition)	Create bean from definition.
private Object	createBeanWithConstructorInjection(Class<?> beanClass)	Create bean using constructor auto-wiring.
private boolean	declaresOwnBeanName(Class<?> type)	True iff type itself carries an explicit @Component(value = ...) or @Service(value = ...) name -- the same condition getBeanName(Class) checks before falling back to a decapitalized-simple-name guess.
private Constructor<?>	findMatchingConstructor(Class<?> beanClass, Object[] args)	Find a matching constructor for the given arguments.
AopProxyResolver	getAopProxyResolver()	Gets the AOP proxy resolver for this container.
AutowireFactory	getAutowireCapableBeanFactory()	Get autowire capable bean factory.
<T> T	getBean(Class<T> type)	Get bean by type.
Object	getBean(String name)	Get bean by name.
<T> T	getBean(String name, Class<T> type)	Get bean by name and type.
String[]	getBeanDefinitionNames()	Get all bean names.
BeanFactory	getBeanFactory()	Get bean factory.
private <T> String	getBeanName(Class<T> type)	Generate bean name for class.
String[]	getBeanNamesForType(Class<?> type)	Get bean names for type.
<T> Map<String,T>	getBeansOfType(Class<T> type)	Get beans of type.
ClassLoader	getClassLoader()	Get class loader.
<T> T	getHighestPriorityBean(Class<T> type)	Get the highest priority bean of the given type.
<T> List<T>	getOrderedBeansOfType(Class<T> type)	Get beans of type ordered by @Service priority.
private int	getServicePriority(Class<?> clazz)	Get service priority from @Service annotation.
protected Object	getSingleton(String beanName, boolean allowEarlyReference)	Get singleton from three-level cache.
Collection<Object>	getSingletonValues()	Get all singleton bean instances registered in this container (not including parent).
Class<?>	getType(String name)	Get bean type.
boolean	hasConstructedInstanceOfType(Class<?> type)	Report whether a constructed instance assignable to type already exists in this container or any parent, without constructing anything.
private void	invalidateResolvedTypeCache()	Invalidates the by-type assignability resolution cache (resolvedTypeCache).
private void	invokePostConstructMethods(Object bean)	Invoke methods annotated with @PostConstruct.
private void	invokePreDestroyMethods(Object bean)	Invoke methods annotated with @PreDestroy on a bean.
private boolean	isAssignable(Class<?> paramType, Object value)	Check if a value can be assigned to a parameter type.
private boolean	isPrimitiveWrapperOf(Class<?> primitive, Class<?> wrapper)	Check if wrapper is the wrapper class for primitive type.
boolean	isPrototype(String name)	Check if bean is prototype.
boolean	isRunning()	Check if container is running.
boolean	isSingleton(String name)	Check if bean is singleton.
void	preInstantiateSingletons()	Initialize all singletons.
void	processConfigurationClass(Class<?> configClass)	Process configuration class.
void	refresh()	Refresh the container.
private void	refuseIfAopAnnotated(Object instance)	Refuses instance when its class carries an AOP annotation (@Transactional/@ExceptionCatch) it can never honour (D-15).
<T> void	registerBean(Class<T> type, Object... constructorArgs)	Register bean with constructor arguments.
void	registerBeanDefinition(String name, BeanDefinition definition)	Register bean definition.
void	registerShutdownHook()	Register shutdown hook.
void	registerSingleton(String name, Object instance)	Registers a singleton instance, fully assembling it before storage.
void	registerSupplier(String name, Supplier<Object> supplier)	Register a supplier for lazy initialization.
void	registerSupplier(String name, Supplier<Object> supplier, Class<?> type)	Register a supplier for lazy initialization with type information.
<T> void	registerType(Class<T> type, T instance)	Register a type mapping.
<T> void	registerTypeSupplier(Class<T> type, Supplier<T> supplier)	Register a type supplier.
void	scanComponents(String... basePackages)	Scan components in packages.
void	setAopProxyResolver(AopProxyResolver resolver)	Sets the AOP proxy resolver for this container.
void	setClassLoader(ClassLoader classLoader)	Set class loader.
void	setDisplayName(String displayName)	Set display name.
void	setParent(SimpleContainer parent)	Set parent container.
void	start()	Start the container.
void	stop()	Stop the container.

Methods inherited from class java.lang.Object

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

Field Details

LOGGER

private static final Logger LOGGER

singletonObjects

private final Map<String,Object> singletonObjects

earlySingletonObjects

private final Map<String,Object> earlySingletonObjects

singletonFactories

private final Map<String,Supplier<Object>> singletonFactories

singletons

private final Map<String,Object> singletons

suppliers

private final Map<String,Supplier<Object>> suppliers

typeMappings

private final Map<Class<?>,Object> typeMappings

typeSuppliers

private final Map<Class<?>,Supplier<Object>> typeSuppliers

resolvedTypeCache

private final Map<Class<?>,Object> resolvedTypeCache

beanScopes

private final Map<String,SimpleContainer.BeanScope> beanScopes

beanTypes

private final Map<String,Class<?>> beanTypes

beanPostProcessors

private final List<BeanPostProcessor> beanPostProcessors

beanDefinitions

private final Map<String,BeanDefinition> beanDefinitions

currentlyCreating

private final Set<String> currentlyCreating

unresolvableBeans

private final Map<String,Throwable> unresolvableBeans

supplierTypes

private final Map<String,Class<?>> supplierTypes

parent

private SimpleContainer parent

classLoader

private ClassLoader classLoader

isStarted

private boolean isStarted

displayName

private String displayName

aopProxyResolver

private AopProxyResolver aopProxyResolver

Resolves which class to instantiate for a bean. Null means AOP is not wired for this container, in which case every bean is instantiated as its declared class.

Constructor Details

SimpleContainer

public SimpleContainer()

SimpleContainer

public SimpleContainer(SimpleContainer parent)

Method Details

getSingleton

protected Object getSingleton(String beanName,
 boolean allowEarlyReference)

Get singleton from three-level cache. This method implements the circular dependency resolution through early singleton exposure.

Parameters:

beanName - bean name

allowEarlyReference - whether to allow early reference (level 2/3 cache)

Returns:

singleton instance or null if not found

addSingletonFactory

protected void addSingletonFactory(String beanName,
 Supplier<Object> singletonFactory)

Add a singleton factory to level 3 cache for early reference support.

Parameters:

beanName - bean name

singletonFactory - factory for creating early reference

addSingleton

protected void addSingleton(String beanName,
 Object singletonObject)

Add a fully initialized singleton to level 1 cache. Clears from level 2 and level 3 caches.

Parameters:

beanName - bean name

singletonObject - fully initialized singleton

registerSingleton

public void registerSingleton(String name,
 Object instance)

Registers a singleton instance, fully assembling it before storage.

Runs the same postProcessBeforeInitialization -> autowireBean -> @PostConstruct -> postProcessAfterInitialization sequence createBean(java.lang.String, com.ultikits.ultitools.context.BeanDefinition) runs for a container-constructed bean, in that order, before storing -- unconditionally, whether or not refresh() has been called. Before 6.3.0 this method was two lines: addSingleton plus a type-mapping write, with no autowiring, no @PostConstruct invocation, and no BeanPostProcessor chain -- an object handed in through this method reached the container half-initialised. refresh() only pre-instantiates non-lazy singleton definitions and never touches a registerSingleton-path object, so gating assembly on refresh state (as a narrower, window-guard fix would) would have left the config entities, the @Configuration instance, and the @Bean products -- all registered before refresh() runs -- exactly as uninjected as before (D-14).

The bean actually stored, and returned by a later getBean(String), is whichever reference postProcessAfterInitialization last returned -- not necessarily instance itself, if a registered BeanPostProcessor substitutes it.

Refuses instance outright when its class carries @Transactional or @ExceptionCatch -- method-level or class-level -- that it can never honour (D-15). A ByteBuddy proxy is the bean itself in this framework's design; there is no separate delegate target, so a proxy can never be retrofitted onto an object the caller already constructed. Before this refusal existed, the annotation was silently inert: the method ran completely unprotected/untransacted, with no signal anything was wrong. An instance that is already a generated proxy (ProxyFactory.isProxyClass(java.lang.Class<?>)) is exempt -- it already honours its own annotations, copied onto the generated subclass by ProxyFactory itself.

No circular-dependency support between two registerSingleton-registered objects (WR-02). Unlike createBean(java.lang.String, com.ultikits.ultitools.context.BeanDefinition), this method does not add an early reference to singletonFactories/earlySingletonObjects before autowiring -- and, unlike createBean, it structurally cannot benefit from doing so. createBean's early exposure works because the container itself triggers a dependency's construction lazily, recursively, inside the same call stack that is still assembling the bean that depends on it -- so an early, not-yet-autowired self-reference can be handed back partway through. A registerSingleton caller, by contrast, hands in an object the caller already fully constructed outside the container; the container never constructs it and has no hook to trigger construction of a second, not-yet-registered object on the first one's behalf. Concretely: if object A and object B are registered via two separate, sequential registerSingleton calls and each has an @Autowired field pointing at the other, A's autowiring runs while B does not exist in this container in any form yet (no definition, no factory, nothing) -- there is nothing an early-reference mechanism could expose. A's field then either throws (if required = true) or stays null (if required = false); B, registered second, resolves normally since A already exists by then. This is reachable by an ordinary module author writing two @Bean methods (or a @Configuration class and one of its own @Bean products) that reference each other, since both paths register their product via this method. Workarounds: order the two registrations so the one with the required = true field is registered second, use @Autowired(required = false) plus manual post-registration wiring, or -- where possible -- register the pair through component scanning instead (@Service/@Component), where createBean(java.lang.String, com.ultikits.ultitools.context.BeanDefinition)'s three-level cache does apply.

Parameters:

name - instance name

instance - instance object

Throws:

ContainerException - if instance's class carries an AOP annotation it can never honour (D-15), or if a required @Autowired dependency on it cannot be resolved (D-08)

refuseIfAopAnnotated

private void refuseIfAopAnnotated(Object instance)

Refuses instance when its class carries an AOP annotation (@Transactional/@ExceptionCatch) it can never honour (D-15).

A generated proxy (ProxyFactory.isProxyClass(java.lang.Class<?>)) is exempt -- it already honours its own annotations. Otherwise, method-level annotations are read via AopEligibility.findAopAnnotatedMethods(java.lang.Class<?>), which deliberately omits class-level ones (see its own javadoc), so the class-level half is checked separately here -- omitting it would leave a class-level @Transactional silently inert, restating SILENT-10 rather than fixing it.

Parameters:

instance - the instance about to be registered

Throws:

ContainerException - naming the offending class and the annotated method (or "class-level") when a refusal applies

registerSupplier

public void registerSupplier(String name,
 Supplier<Object> supplier)

Register a supplier for lazy initialization.

Parameters:

name - supplier name

supplier - supplier function

registerSupplier

public void registerSupplier(String name,
 Supplier<Object> supplier,
 Class<?> type)

Register a supplier for lazy initialization with type information.

Parameters:

name - supplier name

supplier - supplier function

type - the type of bean this supplier produces

registerType

public <T> void registerType(Class<T> type,
 T instance)

Register a type mapping.

Parameters:

type - class type

instance - instance object

registerTypeSupplier

public <T> void registerTypeSupplier(Class<T> type,
 Supplier<T> supplier)

Register a type supplier.

Parameters:

type - class type

supplier - supplier function

getBean

public Object getBean(String name)

Get bean by name.

Parameters:

name - bean name

Returns:

bean instance

getBean

public <T> T getBean(Class<T> type)

Get bean by type.

Parameters:

type - bean type

Returns:

bean instance

getBean

public <T> T getBean(String name,
 Class<T> type)

Get bean by name and type.

Parameters:

name - bean name

type - bean type

Returns:

bean instance

hasConstructedInstanceOfType

public boolean hasConstructedInstanceOfType(Class<?> type)

Report whether a constructed instance assignable to type already exists in this container or any parent, without constructing anything.

This exists because getBeanNamesForType(Class) answers a different question. That method enumerates names, and it draws them from three of the four places an instance can live: singletons, beanDefinitions and supplierTypes. It does not consult typeMappings, so an instance installed only through registerType(Class, Object) -- which writes to that map and nowhere else -- is invisible to a name-based presence check, even though getBean(Class) returns it. A caller asking "is it here?" rather than "what is it called?" needs both.

Name-derived candidates are additionally type-checked against the retrieved singleton: the definition and supplier sources match on declared metadata, so a definition naming type plus a singleton of something else under the same name would otherwise report a presence that is not there.

Neither branch instantiates: getSingleton(String, boolean) is a Level 1 cache read with no early reference, and typeMappings holds already-constructed objects.

Parameters:

type - the type to look for

Returns:

true if a constructed instance assignable to type is already held

Since:

6.3.0

getBeanNamesForType

public String[] getBeanNamesForType(Class<?> type)

Get bean names for type.

Enumerates names from singletons, beanDefinitions and supplierTypes, plus any parent container. It deliberately answers "what is it called", not "is it here": typeMappings holds instances bound by registerType(Class, Object) under no name at all, so they cannot appear here. For a presence question, use hasConstructedInstanceOfType(Class).

Parameters:

type - bean type

Returns:

bean names

getAutowireCapableBeanFactory

public AutowireFactory getAutowireCapableBeanFactory()

Get autowire capable bean factory.

Returns:

autowire factory

close

public void close()

Close the container.

containsBean

public boolean containsBean(String name)

Check if container contains bean.

Parameters:

name - bean name

Returns:

true if contains

registerBean

public <T> void registerBean(Class<T> type,
 Object... constructorArgs)

Register bean with constructor arguments.

Parameters:

type - bean type

constructorArgs - constructor arguments

getBeanName

private <T> String getBeanName(Class<T> type)

Generate bean name for class.

declaresOwnBeanName

private boolean declaresOwnBeanName(Class<?> type)

True iff type itself carries an explicit @Component(value = ...) or @Service(value = ...) name -- the same condition getBeanName(Class) checks before falling back to a decapitalized-simple-name guess.

Used by getBean(Class)'s by-name shortcut (CR-01) to tell a deliberate, specific request ("type declares this exact name as its own") apart from an accidental collision between an unrelated implementer's explicit bean name and an interface's synthesized default -- only the former is a genuine self-match that should skip the priority/ambiguity adjudication a few lines below.

Parameters:

type - the requested type to check

Returns:

true if type declares its own non-empty @Component/@Service name

refresh

public void refresh()

Refresh the container.

getSingletonValues

public Collection<Object> getSingletonValues()

Get all singleton bean instances registered in this container (not including parent).

Returns:

unmodifiable collection of singleton beans

setDisplayName

public void setDisplayName(String displayName)

Set display name.

Parameters:

displayName - display name

setClassLoader

public void setClassLoader(ClassLoader classLoader)

Set class loader.

Parameters:

classLoader - class loader

registerShutdownHook

public void registerShutdownHook()

Register shutdown hook.

setParent

public void setParent(SimpleContainer parent)

Set parent container.

Parameters:

parent - parent container

getBeanFactory

public BeanFactory getBeanFactory()

Get bean factory.

Returns:

bean factory

getClassLoader

public ClassLoader getClassLoader()

Get class loader.

Returns:

class loader

registerBeanDefinition

public void registerBeanDefinition(String name,
 BeanDefinition definition)

Register bean definition.

Parameters:

name - bean name

definition - bean definition

invalidateResolvedTypeCache

private void invalidateResolvedTypeCache()

Invalidates the by-type assignability resolution cache (resolvedTypeCache).

Called whenever a new bean definition or singleton is registered, so a subsequently registered implementation of an already-resolved type participates in the next adjudication instead of being masked by a resolution cached before it existed (D-12). Never touches typeMappings -- that map holds author-declared bindings (registerType/registerTypeSupplier/registerSingleton's own concrete-class binding), which must survive registration of unrelated beans.

createBean

private Object createBean(String name,
 BeanDefinition definition)

Create bean from definition. Uses three-level cache to support circular dependency resolution for setter injection.

Parameters:

name - bean name

definition - bean definition

Returns:

created bean

createBeanWithConstructorInjection

private Object createBeanWithConstructorInjection(Class<?> beanClass)

Create bean using constructor auto-wiring. Resolves constructor parameters from the container.

Parameters:

beanClass - the class to instantiate

Returns:

new bean instance

findMatchingConstructor

private Constructor<?> findMatchingConstructor(Class<?> beanClass,
 Object[] args)
                                        throws NoSuchMethodException

Find a matching constructor for the given arguments. Supports interface/superclass parameter types and primitive type boxing.

Parameters:

beanClass - the class to find constructor for

args - constructor arguments

Returns:

matching constructor

Throws:

NoSuchMethodException

isAssignable

private boolean isAssignable(Class<?> paramType,
 Object value)

Check if a value can be assigned to a parameter type. Handles primitive types, interfaces, and inheritance.

Parameters:

paramType - the parameter type

value - the value to check

Returns:

true if assignable

isPrimitiveWrapperOf

private boolean isPrimitiveWrapperOf(Class<?> primitive,
 Class<?> wrapper)

Check if wrapper is the wrapper class for primitive type.

invokePostConstructMethods

private void invokePostConstructMethods(Object bean)

Invoke methods annotated with @PostConstruct.

Parameters:

bean - the bean instance

invokePreDestroyMethods

private void invokePreDestroyMethods(Object bean)

Invoke methods annotated with @PreDestroy on a bean.

Parameters:

bean - the bean instance

addBeanPostProcessor

public void addBeanPostProcessor(BeanPostProcessor processor)

Add bean post processor.

Parameters:

processor - bean post processor

setAopProxyResolver

public void setAopProxyResolver(AopProxyResolver resolver)

Sets the AOP proxy resolver for this container.

Must be called before refresh(): the resolver participates in bean instantiation, not in post-processing, so beans created earlier would not be proxied.

Parameters:

resolver - the resolver, or null to disable AOP for this container

getAopProxyResolver

public AopProxyResolver getAopProxyResolver()

Gets the AOP proxy resolver for this container.

Returns:

the resolver, or null if AOP is not wired

getBeanDefinitionNames

public String[] getBeanDefinitionNames()

Get all bean names.

Returns:

bean names

getBeansOfType

public <T> Map<String,T> getBeansOfType(Class<T> type)

Get beans of type.

Parameters:

type - bean type

Returns:

beans map

getOrderedBeansOfType

public <T> List<T> getOrderedBeansOfType(Class<T> type)

Get beans of type ordered by @Service priority. Higher priority beans come first.

Parameters:

type - bean type

Returns:

ordered list of beans

getHighestPriorityBean

public <T> T getHighestPriorityBean(Class<T> type)

Get the highest priority bean of the given type.

Parameters:

type - bean type

Returns:

highest priority bean or null

getServicePriority

private int getServicePriority(Class<?> clazz)

Get service priority from @Service annotation.

Parameters:

clazz - the class to check

Returns:

priority value (default 0)

isSingleton

public boolean isSingleton(String name)

Check if bean is singleton.

Parameters:

name - bean name

Returns:

true if singleton

isPrototype

public boolean isPrototype(String name)

Check if bean is prototype.

Parameters:

name - bean name

Returns:

true if prototype

getType

public Class<?> getType(String name)

Get bean type.

Parameters:

name - bean name

Returns:

bean type

preInstantiateSingletons

public void preInstantiateSingletons()

Initialize all singletons.

start

public void start()

Start the container.

stop

public void stop()

Stop the container.

isRunning

public boolean isRunning()

Check if container is running.

Returns:

true if running

scanComponents

public void scanComponents(String... basePackages)

Scan components in packages.

Parameters:

basePackages - packages to scan

processConfigurationClass

public void processConfigurationClass(Class<?> configClass)

Process configuration class.

Reads @ComponentScan through MergedAnnotationResolver.find(java.lang.Class<?>, java.lang.Class<A>) rather than a bare configClass.getAnnotation(ComponentScan.class) -- a class meta-annotated with @UltiToolsModule carries its scanBasePackages()/ scanBasePackageClasses() values onto the merged @ComponentScan view via their @AliasFor declarations (D-01), which a bare lookup would miss entirely. The result is additive across value(), basePackages() and the packages named by basePackageClasses() -- in that declaration order, with duplicates collapsed to their first occurrence (GEN-06) -- not a first-match choice among them.

Parameters:

configClass - configuration class