org.springframework.context.annotation

Class ClassPathBeanDefinitionScanner

java.lang.Object

org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider

org.springframework.context.annotation.ClassPathBeanDefinitionScanner

All Implemented Interfaces:

Aware, ResourceLoaderAware, EnvironmentCapable

public class ClassPathBeanDefinitionScanner
extends ClassPathScanningCandidateComponentProvider

A bean definition scanner that detects bean candidates on the classpath, registering corresponding bean definitions with a given registry (BeanFactory or ApplicationContext).

Candidate classes are detected through configurable type filters. The default filters include classes that are annotated with Spring's @Component, @Repository, @Service, or @Controller stereotype.

Also supports Java EE 6's ManagedBean and JSR-330's Named annotations, if available.

Since:

2.5

Author:

Mark Fisher, Juergen Hoeller, Chris Beams

See Also:

AnnotationConfigApplicationContext.scan(java.lang.String...), Component, Repository, Service, Controller

Field Summary

Fields inherited from class org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider

logger

Constructor Summary

Constructors

Constructor and Description
ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry) Create a new ClassPathBeanDefinitionScanner for the given bean factory.
ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry, boolean useDefaultFilters) Create a new ClassPathBeanDefinitionScanner for the given bean factory.
ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry, boolean useDefaultFilters, Environment environment) Create a new ClassPathBeanDefinitionScanner for the given bean factory and using the given Environment when evaluating bean definition profile metadata.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkCandidate(String beanName, BeanDefinition beanDefinition) Check the given candidate's bean name, determining whether the corresponding bean definition needs to be registered or conflicts with an existing definition.
protected Set<BeanDefinitionHolder>	doScan(String... basePackages) Perform a scan within the specified base packages, returning the registered bean definitions.
BeanDefinitionRegistry	getRegistry() Return the BeanDefinitionRegistry that this scanner operates on.
protected boolean	isCompatible(BeanDefinition newDefinition, BeanDefinition existingDefinition) Determine whether the given new bean definition is compatible with the given existing bean definition.
protected void	postProcessBeanDefinition(AbstractBeanDefinition beanDefinition, String beanName) Apply further settings to the given bean definition, beyond the contents retrieved from scanning the component class.
protected void	registerBeanDefinition(BeanDefinitionHolder definitionHolder, BeanDefinitionRegistry registry) Register the specified bean with the given registry.
int	scan(String... basePackages) Perform a scan within the specified base packages.
void	setAutowireCandidatePatterns(String[] autowireCandidatePatterns) Set the name-matching patterns for determining autowire candidates.
void	setBeanDefinitionDefaults(BeanDefinitionDefaults beanDefinitionDefaults) Set the defaults to use for detected beans.
void	setBeanNameGenerator(BeanNameGenerator beanNameGenerator) Set the BeanNameGenerator to use for detected bean classes.
void	setIncludeAnnotationConfig(boolean includeAnnotationConfig) Specify whether to register annotation config post-processors.
void	setScopedProxyMode(ScopedProxyMode scopedProxyMode) Specify the proxy behavior for non-singleton scoped beans.
void	setScopeMetadataResolver(ScopeMetadataResolver scopeMetadataResolver) Set the ScopeMetadataResolver to use for detected bean classes.

Methods inherited from class org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider

addExcludeFilter, addIncludeFilter, clearCache, findCandidateComponents, getEnvironment, getMetadataReaderFactory, getResourceLoader, isCandidateComponent, isCandidateComponent, registerDefaultFilters, resetFilters, resolveBasePackage, setEnvironment, setMetadataReaderFactory, setResourceLoader, setResourcePattern

Methods inherited from class java.lang.Object

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

Constructor Detail

ClassPathBeanDefinitionScanner

public ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry)

Create a new ClassPathBeanDefinitionScanner for the given bean factory.

Parameters:

registry - the BeanFactory to load bean definitions into, in the form of a BeanDefinitionRegistry

ClassPathBeanDefinitionScanner

public ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry,
                                      boolean useDefaultFilters)

Create a new ClassPathBeanDefinitionScanner for the given bean factory.

If the passed-in bean factory does not only implement the BeanDefinitionRegistry interface but also the ResourceLoader interface, it will be used as default ResourceLoader as well. This will usually be the case for ApplicationContext implementations.

If given a plain BeanDefinitionRegistry, the default ResourceLoader will be a PathMatchingResourcePatternResolver.

If the the passed-in bean factory also implements EnvironmentCapable its environment will be used by this reader. Otherwise, the reader will initialize and use a StandardEnvironment. All ApplicationContext implementations are EnvironmentCapable, while normal BeanFactory implementations are not.

Parameters:

registry - the BeanFactory to load bean definitions into, in the form of a BeanDefinitionRegistry

useDefaultFilters - whether to include the default filters for the @Component, @Repository, @Service, and @Controller stereotype annotations.

See Also:

ClassPathScanningCandidateComponentProvider.setResourceLoader(org.springframework.core.io.ResourceLoader), ClassPathScanningCandidateComponentProvider.setEnvironment(org.springframework.core.env.Environment)

ClassPathBeanDefinitionScanner

public ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry,
                                      boolean useDefaultFilters,
                                      Environment environment)

Create a new ClassPathBeanDefinitionScanner for the given bean factory and using the given Environment when evaluating bean definition profile metadata.

If the passed-in bean factory does not only implement the BeanDefinitionRegistry interface but also the ResourceLoader interface, it will be used as default ResourceLoader as well. This will usually be the case for ApplicationContext implementations.

If given a plain BeanDefinitionRegistry, the default ResourceLoader will be a PathMatchingResourcePatternResolver.

Parameters:

registry - the BeanFactory to load bean definitions into, in the form of a BeanDefinitionRegistry

useDefaultFilters - whether to include the default filters for the

environment - the Spring Environment to use when evaluating bean definition profile metadata. @Component, @Repository, @Service, and @Controller stereotype annotations.

Since:

3.1

See Also:

ClassPathScanningCandidateComponentProvider.setResourceLoader(org.springframework.core.io.ResourceLoader)

Method Detail

getRegistry

public final BeanDefinitionRegistry getRegistry()

Return the BeanDefinitionRegistry that this scanner operates on.

Overrides:

getRegistry in class ClassPathScanningCandidateComponentProvider

setBeanDefinitionDefaults

public void setBeanDefinitionDefaults(BeanDefinitionDefaults beanDefinitionDefaults)

Set the defaults to use for detected beans.

See Also:

BeanDefinitionDefaults

setAutowireCandidatePatterns

public void setAutowireCandidatePatterns(String[] autowireCandidatePatterns)

Set the name-matching patterns for determining autowire candidates.

Parameters:

autowireCandidatePatterns - the patterns to match against

setBeanNameGenerator

public void setBeanNameGenerator(BeanNameGenerator beanNameGenerator)

Set the BeanNameGenerator to use for detected bean classes.

Default is a AnnotationBeanNameGenerator.

setScopeMetadataResolver

public void setScopeMetadataResolver(ScopeMetadataResolver scopeMetadataResolver)

Set the ScopeMetadataResolver to use for detected bean classes. Note that this will override any custom "scopedProxyMode" setting.

The default is an AnnotationScopeMetadataResolver.

See Also:

setScopedProxyMode(org.springframework.context.annotation.ScopedProxyMode)

setScopedProxyMode

public void setScopedProxyMode(ScopedProxyMode scopedProxyMode)

Specify the proxy behavior for non-singleton scoped beans. Note that this will override any custom "scopeMetadataResolver" setting.

The default is ScopedProxyMode.NO.

See Also:

setScopeMetadataResolver(org.springframework.context.annotation.ScopeMetadataResolver)

setIncludeAnnotationConfig

public void setIncludeAnnotationConfig(boolean includeAnnotationConfig)

Specify whether to register annotation config post-processors.

The default is to register the post-processors. Turn this off to be able to ignore the annotations or to process them differently.

scan

public int scan(String... basePackages)

Perform a scan within the specified base packages.

Parameters:

basePackages - the packages to check for annotated classes

Returns:

number of beans registered

doScan

protected Set<BeanDefinitionHolder> doScan(String... basePackages)

Perform a scan within the specified base packages, returning the registered bean definitions.

This method does not register an annotation config processor but rather leaves this up to the caller.

Parameters:

basePackages - the packages to check for annotated classes

Returns:

set of beans registered if any for tooling registration purposes (never null)

postProcessBeanDefinition

protected void postProcessBeanDefinition(AbstractBeanDefinition beanDefinition,
                                         String beanName)

Apply further settings to the given bean definition, beyond the contents retrieved from scanning the component class.

Parameters:

beanDefinition - the scanned bean definition

beanName - the generated bean name for the given bean

registerBeanDefinition

protected void registerBeanDefinition(BeanDefinitionHolder definitionHolder,
                                      BeanDefinitionRegistry registry)

Register the specified bean with the given registry.

Can be overridden in subclasses, e.g. to adapt the registration process or to register further bean definitions for each scanned bean.

Parameters:

definitionHolder - the bean definition plus bean name for the bean

registry - the BeanDefinitionRegistry to register the bean with

checkCandidate

protected boolean checkCandidate(String beanName,
                                 BeanDefinition beanDefinition)
                          throws IllegalStateException

Check the given candidate's bean name, determining whether the corresponding bean definition needs to be registered or conflicts with an existing definition.

Parameters:

beanName - the suggested name for the bean

beanDefinition - the corresponding bean definition

Returns:

true if the bean can be registered as-is; false if it should be skipped because there is an existing, compatible bean definition for the specified name

Throws:

ConflictingBeanDefinitionException - if an existing, incompatible bean definition has been found for the specified name

IllegalStateException

isCompatible

protected boolean isCompatible(BeanDefinition newDefinition,
                               BeanDefinition existingDefinition)

Determine whether the given new bean definition is compatible with the given existing bean definition.

The default implementation considers them as compatible when the existing bean definition comes from the same source or from a non-scanning source.

Parameters:

newDefinition - the new bean definition, originated from scanning

existingDefinition - the existing bean definition, potentially an explicitly defined one or a previously generated one from scanning

Returns:

whether the definitions are considered as compatible, with the new definition to be skipped in favor of the existing definition