Class CandidateComponentsIndexLoader

java.lang.Object

org.springframework.context.index.CandidateComponentsIndexLoader

public final class CandidateComponentsIndexLoader
extends Object

Candidate components index loading mechanism for internal use within the framework.

Since:

5.0

Author:

Stephane Nicoll, Juergen Hoeller

Field Summary

Fields

Modifier and Type	Field	Description
static final String	COMPONENTS_RESOURCE_LOCATION	The location to look for components.
static final String	IGNORE_INDEX	System property that instructs Spring to ignore the components index, i.e.

Method Summary

Modifier and Type	Method	Description
static void	addIndex(ClassLoader classLoader, CandidateComponentsIndex index)	Programmatically add the given index instance for the given ClassLoader, replacing a file-determined index with a programmatically composed index.
static void	clearCache()	Clear the runtime index cache.
static @Nullable CandidateComponentsIndex	loadIndex(@Nullable ClassLoader classLoader)	Load and instantiate the CandidateComponentsIndex from "META-INF/spring.components", using the given class loader.

Methods inherited from class Object

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

Field Details

COMPONENTS_RESOURCE_LOCATION

public static final String COMPONENTS_RESOURCE_LOCATION

The location to look for components.

Can be present in multiple JAR files.

See Also:

• Constant Field Values

IGNORE_INDEX

public static final String IGNORE_INDEX

System property that instructs Spring to ignore the components index, i.e. to always return null from loadIndex(ClassLoader).

The default is "false", allowing for regular use of the index. Switching this flag to true fulfills a corner case scenario when an index is partially available for some libraries (or use cases) but couldn't be built for the whole application. In this case, the application context fallbacks to a regular classpath arrangement (i.e. as though no index were present at all).

See Also:

• Constant Field Values

Method Details

loadIndex

public static @Nullable CandidateComponentsIndex loadIndex(@Nullable ClassLoader classLoader)

Load and instantiate the CandidateComponentsIndex from "META-INF/spring.components", using the given class loader. If no index is available, return null.

Parameters:

classLoader - the ClassLoader to use for loading (can be null to use the default)

Returns:

the index to use or null if no index was found

Throws:

IllegalArgumentException - if any module index cannot be loaded or if an error occurs while creating CandidateComponentsIndex

addIndex

public static void addIndex(ClassLoader classLoader,
 CandidateComponentsIndex index)

Programmatically add the given index instance for the given ClassLoader, replacing a file-determined index with a programmatically composed index.

The index instance will usually be pre-populated for AOT runtime setups or test scenarios with pre-configured results for runtime-attempted scans. Alternatively, it may be empty for it to get populated during AOT processing or a test run, for subsequent introspection the index-recorded candidate types.

Parameters:

classLoader - the ClassLoader to add the index for

index - the associated CandidateComponentsIndex instance

Since:

7.0

clearCache

public static void clearCache()

Clear the runtime index cache.

Since:

7.0