org.springframework.beans.factory.support
Class ConstructorResolver

java.lang.Object
  org.springframework.beans.factory.support.ConstructorResolver

 class ConstructorResolver
extends java.lang.Object

Helper class for resolving constructors and factory methods. Performs constructor resolution through argument matching.

Operates on an AbstractBeanFactory and an InstantiationStrategy. Used by AbstractAutowireCapableBeanFactory.

Since:

2.0

Author:

Juergen Hoeller, Rob Harrop, Mark Fisher, Costin Leau

See Also:

autowireConstructor(java.lang.String, org.springframework.beans.factory.support.RootBeanDefinition, java.lang.reflect.Constructor[], java.lang.Object[]), instantiateUsingFactoryMethod(java.lang.String, org.springframework.beans.factory.support.RootBeanDefinition, java.lang.Object[]), AbstractAutowireCapableBeanFactory

Nested Class Summary

private static class	ConstructorResolver.ArgumentsHolder Private inner class for holding argument combinations.
private static class	ConstructorResolver.AutowiredArgumentMarker Marker for autowired arguments in a cached argument array.
private static class	ConstructorResolver.ConstructorPropertiesChecker Inner class to avoid a Java 6 dependency.

Field Summary

private AbstractAutowireCapableBeanFactory	beanFactory
private static java.lang.String	CONSTRUCTOR_PROPERTIES_CLASS_NAME
private static boolean	constructorPropertiesAnnotationAvailable

Constructor Summary

ConstructorResolver(AbstractAutowireCapableBeanFactory beanFactory)
Create a new ConstructorResolver for the given factory and instantiation strategy.

Method Summary

BeanWrapper	autowireConstructor(java.lang.String beanName, RootBeanDefinition mbd, java.lang.reflect.Constructor[] chosenCtors, java.lang.Object[] explicitArgs) "autowire constructor" (with constructor arguments by type) behavior.
private ConstructorResolver.ArgumentsHolder	createArgumentArray(java.lang.String beanName, RootBeanDefinition mbd, ConstructorArgumentValues resolvedValues, BeanWrapper bw, java.lang.Class[] paramTypes, java.lang.String[] paramNames, java.lang.Object methodOrCtor, boolean autowiring) Create an array of arguments to invoke a constructor or factory method, given the resolved constructor argument values.
BeanWrapper	instantiateUsingFactoryMethod(java.lang.String beanName, RootBeanDefinition mbd, java.lang.Object[] explicitArgs) Instantiate the bean using a named factory method.
protected java.lang.Object	resolveAutowiredArgument(MethodParameter param, java.lang.String beanName, java.util.Set<java.lang.String> autowiredBeanNames, TypeConverter typeConverter) Template method for resolving the specified argument which is supposed to be autowired.
private int	resolveConstructorArguments(java.lang.String beanName, RootBeanDefinition mbd, BeanWrapper bw, ConstructorArgumentValues cargs, ConstructorArgumentValues resolvedValues) Resolve the constructor arguments for this bean into the resolvedValues object.
void	resolveFactoryMethodIfPossible(RootBeanDefinition mbd) Resolve the factory method in the specified bean definition, if possible.
private java.lang.Object[]	resolvePreparedArguments(java.lang.String beanName, RootBeanDefinition mbd, BeanWrapper bw, java.lang.reflect.Member methodOrCtor, java.lang.Object[] argsToResolve) Resolve the prepared arguments stored in the given bean definition.

Methods inherited from class java.lang.Object

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

Field Detail

CONSTRUCTOR_PROPERTIES_CLASS_NAME

private static final java.lang.String CONSTRUCTOR_PROPERTIES_CLASS_NAME

See Also:

Constant Field Values

constructorPropertiesAnnotationAvailable

private static final boolean constructorPropertiesAnnotationAvailable

beanFactory

private final AbstractAutowireCapableBeanFactory beanFactory

Constructor Detail

ConstructorResolver

public ConstructorResolver(AbstractAutowireCapableBeanFactory beanFactory)

Create a new ConstructorResolver for the given factory and instantiation strategy.

Parameters:

beanFactory - the BeanFactory to work with

Method Detail

autowireConstructor

public BeanWrapper autowireConstructor(java.lang.String beanName,
                                       RootBeanDefinition mbd,
                                       java.lang.reflect.Constructor[] chosenCtors,
                                       java.lang.Object[] explicitArgs)

"autowire constructor" (with constructor arguments by type) behavior. Also applied if explicit constructor argument values are specified, matching all remaining arguments with beans from the bean factory.

This corresponds to constructor injection: In this mode, a Spring bean factory is able to host components that expect constructor-based dependency resolution.

Parameters:

beanName - the name of the bean

mbd - the merged bean definition for the bean

chosenCtors - chosen candidate constructors (or null if none)

explicitArgs - argument values passed in programmatically via the getBean method, or null if none (-> use constructor argument values from bean definition)

Returns:

a BeanWrapper for the new instance

resolveFactoryMethodIfPossible

public void resolveFactoryMethodIfPossible(RootBeanDefinition mbd)

Resolve the factory method in the specified bean definition, if possible. RootBeanDefinition.getResolvedFactoryMethod() can be checked for the result.

Parameters:

mbd - the bean definition to check

instantiateUsingFactoryMethod

public BeanWrapper instantiateUsingFactoryMethod(java.lang.String beanName,
                                                 RootBeanDefinition mbd,
                                                 java.lang.Object[] explicitArgs)

Instantiate the bean using a named factory method. The method may be static, if the bean definition parameter specifies a class, rather than a "factory-bean", or an instance variable on a factory object itself configured using Dependency Injection.

Implementation requires iterating over the static or instance methods with the name specified in the RootBeanDefinition (the method may be overloaded) and trying to match with the parameters. We don't have the types attached to constructor args, so trial and error is the only way to go here. The explicitArgs array may contain argument values passed in programmatically via the corresponding getBean method.

Parameters:

beanName - the name of the bean

mbd - the merged bean definition for the bean

explicitArgs - argument values passed in programmatically via the getBean method, or null if none (-> use constructor argument values from bean definition)

Returns:

a BeanWrapper for the new instance

resolveConstructorArguments

private int resolveConstructorArguments(java.lang.String beanName,
                                        RootBeanDefinition mbd,
                                        BeanWrapper bw,
                                        ConstructorArgumentValues cargs,
                                        ConstructorArgumentValues resolvedValues)

Resolve the constructor arguments for this bean into the resolvedValues object. This may involve looking up other beans. This method is also used for handling invocations of static factory methods.

createArgumentArray

private ConstructorResolver.ArgumentsHolder createArgumentArray(java.lang.String beanName,
                                                                RootBeanDefinition mbd,
                                                                ConstructorArgumentValues resolvedValues,
                                                                BeanWrapper bw,
                                                                java.lang.Class[] paramTypes,
                                                                java.lang.String[] paramNames,
                                                                java.lang.Object methodOrCtor,
                                                                boolean autowiring)
                                                         throws UnsatisfiedDependencyException

Create an array of arguments to invoke a constructor or factory method, given the resolved constructor argument values.

Throws:

UnsatisfiedDependencyException

resolvePreparedArguments

private java.lang.Object[] resolvePreparedArguments(java.lang.String beanName,
                                                    RootBeanDefinition mbd,
                                                    BeanWrapper bw,
                                                    java.lang.reflect.Member methodOrCtor,
                                                    java.lang.Object[] argsToResolve)

Resolve the prepared arguments stored in the given bean definition.

resolveAutowiredArgument

protected java.lang.Object resolveAutowiredArgument(MethodParameter param,
                                                    java.lang.String beanName,
                                                    java.util.Set<java.lang.String> autowiredBeanNames,
                                                    TypeConverter typeConverter)

Template method for resolving the specified argument which is supposed to be autowired.