org.springframework.core.io.support

Class SpringFactoriesLoader

java.lang.Object

org.springframework.core.io.support.SpringFactoriesLoader

public abstract class SpringFactoriesLoader
extends Object

General purpose factory loading mechanism for internal use within the framework.

SpringFactoriesLoader loads and instantiates factories of a given type from "META-INF/spring.factories" files which may be present in multiple JAR files in the classpath. The spring.factories file must be in Properties format, where the key is the fully qualified name of the interface or abstract class, and the value is a comma-separated list of implementation class names. For example:

example.MyService=example.MyServiceImpl1,example.MyServiceImpl2

where example.MyService is the name of the interface, and MyServiceImpl1 and MyServiceImpl2 are two implementations.

Since:

3.2

Author:

Arjen Poutsma, Juergen Hoeller, Sam Brannen

Field Summary

Fields

Modifier and Type	Field and Description
static String	FACTORIES_RESOURCE_LOCATION The location to look for factories.

Constructor Summary

Constructors

Constructor and Description
SpringFactoriesLoader()

Method Summary

Modifier and Type	Method and Description
static <T> List<T>	loadFactories(Class<T> factoryClass, ClassLoader classLoader) Load and instantiate the factory implementations of the given type from "META-INF/spring.factories", using the given class loader.
static List<String>	loadFactoryNames(Class<?> factoryClass, ClassLoader classLoader) Load the fully qualified class names of factory implementations of the given type from "META-INF/spring.factories", using the given class loader.

Methods inherited from class java.lang.Object

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

Field Detail

FACTORIES_RESOURCE_LOCATION

public static final String FACTORIES_RESOURCE_LOCATION

The location to look for factories.

Can be present in multiple JAR files.

See Also:

Constant Field Values

Constructor Detail

SpringFactoriesLoader

public SpringFactoriesLoader()

Method Detail

loadFactories

public static <T> List<T> loadFactories(Class<T> factoryClass,
                                        ClassLoader classLoader)

Load and instantiate the factory implementations of the given type from "META-INF/spring.factories", using the given class loader.

The returned factories are sorted in accordance with the AnnotationAwareOrderComparator.

If a custom instantiation strategy is required, use loadFactoryNames(java.lang.Class<?>, java.lang.ClassLoader) to obtain all registered factory names.

Parameters:

factoryClass - the interface or abstract class representing the factory

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

Throws:

IllegalArgumentException - if any factory implementation class cannot be loaded or if an error occurs while instantiating any factory

See Also:

loadFactoryNames(java.lang.Class<?>, java.lang.ClassLoader)

loadFactoryNames

public static List<String> loadFactoryNames(Class<?> factoryClass,
                                            ClassLoader classLoader)

Load the fully qualified class names of factory implementations of the given type from "META-INF/spring.factories", using the given class loader.

Parameters:

factoryClass - the interface or abstract class representing the factory

classLoader - the ClassLoader to use for loading resources; can be null to use the default

Throws:

IllegalArgumentException - if an error occurs while loading factory names

See Also:

loadFactories(java.lang.Class<T>, java.lang.ClassLoader)