org.springframework.context.annotation
Class ClassPathScanningCandidateComponentProvider

java.lang.Object
  extended by org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider
All Implemented Interfaces:
Aware, ResourceLoaderAware, EnvironmentCapable
Direct Known Subclasses:
ClassPathBeanDefinitionScanner

public class ClassPathScanningCandidateComponentProvider
extends Object
implements EnvironmentCapable, ResourceLoaderAware

A component provider that scans the classpath from a base package. It then applies exclude and include filters to the resulting classes to find candidates.

This implementation is based on Spring's MetadataReader facility, backed by an ASM ClassReader.

Since:
2.5
Author:
Mark Fisher, Juergen Hoeller, Ramnivas Laddad, Chris Beams
See Also:
MetadataReaderFactory, AnnotationMetadata, ScannedGenericBeanDefinition

Field Summary
protected  Log logger
           
 
Constructor Summary
ClassPathScanningCandidateComponentProvider(boolean useDefaultFilters)
          Create a ClassPathScanningCandidateComponentProvider.
 
Method Summary
 void addExcludeFilter(TypeFilter excludeFilter)
          Add an exclude type filter to the front of the exclusion list.
 void addIncludeFilter(TypeFilter includeFilter)
          Add an include type filter to the end of the inclusion list.
 Set<BeanDefinition> findCandidateComponents(String basePackage)
          Scan the class path for candidate components.
 Environment getEnvironment()
          Return the Environment for this object
 ResourceLoader getResourceLoader()
          Return the ResourceLoader that this component provider uses.
protected  boolean isCandidateComponent(AnnotatedBeanDefinition beanDefinition)
          Determine whether the given bean definition qualifies as candidate.
protected  boolean isCandidateComponent(MetadataReader metadataReader)
          Determine whether the given class does not match any exclude filter and does match at least one include filter.
protected  void registerDefaultFilters()
          Register the default filter for @Component.
 void resetFilters(boolean useDefaultFilters)
          Reset the configured type filters.
protected  String resolveBasePackage(String basePackage)
          Resolve the specified base package into a pattern specification for the package search path.
 void setEnvironment(Environment environment)
          Set the Environment to use when resolving placeholders and evaluating @Profile-annotated component classes.
 void setResourceLoader(ResourceLoader resourceLoader)
          Set the ResourceLoader to use for resource locations.
 void setResourcePattern(String resourcePattern)
          Set the resource pattern to use when scanning the classpath.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

logger

protected final Log logger
Constructor Detail

ClassPathScanningCandidateComponentProvider

public ClassPathScanningCandidateComponentProvider(boolean useDefaultFilters)
Create a ClassPathScanningCandidateComponentProvider.

Parameters:
useDefaultFilters - whether to register the default filters for the @Component, @Repository, @Service, and @Controller stereotype annotations
See Also:
registerDefaultFilters()
Method Detail

setResourceLoader

public void setResourceLoader(ResourceLoader resourceLoader)
Set the ResourceLoader to use for resource locations. This will typically be a ResourcePatternResolver implementation.

Default is PathMatchingResourcePatternResolver, also capable of resource pattern resolving through the ResourcePatternResolver interface.

Specified by:
setResourceLoader in interface ResourceLoaderAware
Parameters:
resourceLoader - ResourceLoader object to be used by this object
See Also:
ResourcePatternResolver, PathMatchingResourcePatternResolver

setEnvironment

public void setEnvironment(Environment environment)
Set the Environment to use when resolving placeholders and evaluating @Profile-annotated component classes.

The default is a DefaultEnvironment

Parameters:
environment - the Environment to use

getEnvironment

public Environment getEnvironment()
Description copied from interface: EnvironmentCapable
Return the Environment for this object

Specified by:
getEnvironment in interface EnvironmentCapable

getResourceLoader

public final ResourceLoader getResourceLoader()
Return the ResourceLoader that this component provider uses.


setResourcePattern

public void setResourcePattern(String resourcePattern)
Set the resource pattern to use when scanning the classpath. This value will be appended to each base package name.

See Also:
findCandidateComponents(String), DEFAULT_RESOURCE_PATTERN

addIncludeFilter

public void addIncludeFilter(TypeFilter includeFilter)
Add an include type filter to the end of the inclusion list.


addExcludeFilter

public void addExcludeFilter(TypeFilter excludeFilter)
Add an exclude type filter to the front of the exclusion list.


resetFilters

public void resetFilters(boolean useDefaultFilters)
Reset the configured type filters.

Parameters:
useDefaultFilters - whether to re-register the default filters for the @Component, @Repository, @Service, and @Controller stereotype annotations
See Also:
registerDefaultFilters()

registerDefaultFilters

protected void registerDefaultFilters()
Register the default filter for @Component.

This will implicitly register all annotations that have the @Component meta-annotation including the @Repository, @Service, and @Controller stereotype annotations.

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


findCandidateComponents

public Set<BeanDefinition> findCandidateComponents(String basePackage)
Scan the class path for candidate components.

Parameters:
basePackage - the package to check for annotated classes
Returns:
a corresponding Set of autodetected bean definitions

resolveBasePackage

protected String resolveBasePackage(String basePackage)
Resolve the specified base package into a pattern specification for the package search path.

The default implementation resolves placeholders against system properties, and converts a "."-based package path to a "/"-based resource path.

Parameters:
basePackage - the base package as specified by the user
Returns:
the pattern specification to be used for package searching

isCandidateComponent

protected boolean isCandidateComponent(MetadataReader metadataReader)
                                throws IOException
Determine whether the given class does not match any exclude filter and does match at least one include filter.

Parameters:
metadataReader - the ASM ClassReader for the class
Returns:
whether the class qualifies as a candidate component
Throws:
IOException

isCandidateComponent

protected boolean isCandidateComponent(AnnotatedBeanDefinition beanDefinition)
Determine whether the given bean definition qualifies as candidate.

The default implementation checks whether the class is concrete (i.e. not abstract and not an interface). Can be overridden in subclasses.

Parameters:
beanDefinition - the bean definition to check
Returns:
whether the bean definition qualifies as a candidate component