## org.springframework.context.annotation
Class ClassPathScanningCandidateComponentProvider

    java.lang.Object
      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.
`ClassPathScanningCandidateComponentProvider(boolean useDefaultFilters, Environment environment)`

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()`

### ClassPathScanningCandidateComponentProvider

    public ClassPathScanningCandidateComponentProvider(boolean useDefaultFilters,
                                                       Environment environment)

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`

### getResourceLoader

    public final ResourceLoader getResourceLoader()

  Return the ResourceLoader that this component provider uses.

### setEnvironment

    public void setEnvironment(Environment environment)

  Set the Environment to use when resolving placeholders and evaluating `@Profile`-annotated component classes.

  The default is a `StandardEnvironment`

  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`

### 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