org.springframework.context.annotation
Class ClassPathBeanDefinitionScanner

java.lang.Object
  extended by org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider
      extended by 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
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.
 
Method Summary
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, findCandidateComponents, getEnvironment, getResourceLoader, isCandidateComponent, isCandidateComponent, registerDefaultFilters, resetFilters, resolveBasePackage, setEnvironment, 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 DefaultEnvironment. 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)
Method Detail

getRegistry

public final BeanDefinitionRegistry getRegistry()
Return the BeanDefinitionRegistry that this scanner operates on.


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

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 simply considers them as compatible when the bean class name matches.

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