https://github.com/spring-projects/spring-framework: Spring Context (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.context.annotation;

import java.util.function.Supplier;

import org.springframework.beans.factory.config.BeanDefinitionCustomizer;
import org.springframework.beans.factory.support.BeanNameGenerator;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.context.support.GenericApplicationContext;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;


Standalone application context, accepting annotated classes as input - in particular @Configuration-annotated classes, but also plain @Component types and JSR-330 compliant classes using javax.inject annotations. Allows for registering classes one by one using register(Class<?>...) as well as for classpath scanning using scan(String...). 
In case of multiple @Configuration classes, @Bean methods defined in later classes will override those defined in earlier classes. This can be leveraged to deliberately override certain bean definitions via an extra @Configuration class. 
See @Configuration's javadoc for usage examples. 
Author:Juergen Hoeller, Chris Beams
See Also:
Since:3.0
/**
 * Standalone application context, accepting annotated classes as input - in particular
 * {@link Configuration @Configuration}-annotated classes, but also plain
 * {@link org.springframework.stereotype.Component @Component} types and JSR-330 compliant
 * classes using {@code javax.inject} annotations. Allows for registering classes one by
 * one using {@link #register(Class...)} as well as for classpath scanning using
 * {@link #scan(String...)}.
 *
 * <p>In case of multiple {@code @Configuration} classes, @{@link Bean} methods defined in
 * later classes will override those defined in earlier classes. This can be leveraged to
 * deliberately override certain bean definitions via an extra {@code @Configuration}
 * class.
 *
 * <p>See @{@link Configuration}'s javadoc for usage examples.
 *
 * @author Juergen Hoeller
 * @author Chris Beams
 * @since 3.0
 * @see #register
 * @see #scan
 * @see AnnotatedBeanDefinitionReader
 * @see ClassPathBeanDefinitionScanner
 * @see org.springframework.context.support.GenericXmlApplicationContext
 */
public class AnnotationConfigApplicationContext extends GenericApplicationContext implements AnnotationConfigRegistry {

	private final AnnotatedBeanDefinitionReader reader;

	private final ClassPathBeanDefinitionScanner scanner;


	
Create a new AnnotationConfigApplicationContext that needs to be populated through register calls and then manually refreshed. 
/**
	 * Create a new AnnotationConfigApplicationContext that needs to be populated
	 * through {@link #register} calls and then manually {@linkplain #refresh refreshed}.
	 */
	public AnnotationConfigApplicationContext() {
		this.reader = new AnnotatedBeanDefinitionReader(this);
		this.scanner = new ClassPathBeanDefinitionScanner(this);
	}

	
Create a new AnnotationConfigApplicationContext with the given DefaultListableBeanFactory.

Params:
  • beanFactory – the DefaultListableBeanFactory instance to use for this context
/**
	 * Create a new AnnotationConfigApplicationContext with the given DefaultListableBeanFactory.
	 * @param beanFactory the DefaultListableBeanFactory instance to use for this context
	 */
	public AnnotationConfigApplicationContext(DefaultListableBeanFactory beanFactory) {
		super(beanFactory);
		this.reader = new AnnotatedBeanDefinitionReader(this);
		this.scanner = new ClassPathBeanDefinitionScanner(this);
	}

	
Create a new AnnotationConfigApplicationContext, deriving bean definitions
from the given annotated classes and automatically refreshing the context.

Params:
  • annotatedClasses – one or more annotated classes, e.g. @Configuration classes
/**
	 * Create a new AnnotationConfigApplicationContext, deriving bean definitions
	 * from the given annotated classes and automatically refreshing the context.
	 * @param annotatedClasses one or more annotated classes,
	 * e.g. {@link Configuration @Configuration} classes
	 */
	public AnnotationConfigApplicationContext(Class<?>... annotatedClasses) {
		this();
		register(annotatedClasses);
		refresh();
	}

	
Create a new AnnotationConfigApplicationContext, scanning for bean definitions
in the given packages and automatically refreshing the context.

Params:
  • basePackages – the packages to check for annotated classes
/**
	 * Create a new AnnotationConfigApplicationContext, scanning for bean definitions
	 * in the given packages and automatically refreshing the context.
	 * @param basePackages the packages to check for annotated classes
	 */
	public AnnotationConfigApplicationContext(String... basePackages) {
		this();
		scan(basePackages);
		refresh();
	}


	
Propagates the given custom Environment to the underlying AnnotatedBeanDefinitionReader and ClassPathBeanDefinitionScanner. 
/**
	 * Propagates the given custom {@code Environment} to the underlying
	 * {@link AnnotatedBeanDefinitionReader} and {@link ClassPathBeanDefinitionScanner}.
	 */
	@Override
	public void setEnvironment(ConfigurableEnvironment environment) {
		super.setEnvironment(environment);
		this.reader.setEnvironment(environment);
		this.scanner.setEnvironment(environment);
	}

	
Provide a custom BeanNameGenerator for use with AnnotatedBeanDefinitionReader and/or ClassPathBeanDefinitionScanner, if any. 
Default is AnnotationBeanNameGenerator. 
Any call to this method must occur prior to calls to register(Class<?>...) and/or scan(String...). 
See Also:
/**
	 * Provide a custom {@link BeanNameGenerator} for use with {@link AnnotatedBeanDefinitionReader}
	 * and/or {@link ClassPathBeanDefinitionScanner}, if any.
	 * <p>Default is {@link org.springframework.context.annotation.AnnotationBeanNameGenerator}.
	 * <p>Any call to this method must occur prior to calls to {@link #register(Class...)}
	 * and/or {@link #scan(String...)}.
	 * @see AnnotatedBeanDefinitionReader#setBeanNameGenerator
	 * @see ClassPathBeanDefinitionScanner#setBeanNameGenerator
	 */
	public void setBeanNameGenerator(BeanNameGenerator beanNameGenerator) {
		this.reader.setBeanNameGenerator(beanNameGenerator);
		this.scanner.setBeanNameGenerator(beanNameGenerator);
		getBeanFactory().registerSingleton(
				AnnotationConfigUtils.CONFIGURATION_BEAN_NAME_GENERATOR, beanNameGenerator);
	}

	
Set the ScopeMetadataResolver to use for detected bean classes. 
The default is an AnnotationScopeMetadataResolver. 
Any call to this method must occur prior to calls to register(Class<?>...) and/or scan(String...). 
/**
	 * Set the {@link ScopeMetadataResolver} to use for detected bean classes.
	 * <p>The default is an {@link AnnotationScopeMetadataResolver}.
	 * <p>Any call to this method must occur prior to calls to {@link #register(Class...)}
	 * and/or {@link #scan(String...)}.
	 */
	public void setScopeMetadataResolver(ScopeMetadataResolver scopeMetadataResolver) {
		this.reader.setScopeMetadataResolver(scopeMetadataResolver);
		this.scanner.setScopeMetadataResolver(scopeMetadataResolver);
	}


	//---------------------------------------------------------------------
	// Implementation of AnnotationConfigRegistry
	//---------------------------------------------------------------------

	
Register one or more annotated classes to be processed.

Note that AbstractApplicationContext.refresh() must be called in order for the context to fully process the new classes. 
Params:
  • annotatedClasses – one or more annotated classes, e.g. @Configuration classes
See Also:
/**
	 * Register one or more annotated classes to be processed.
	 * <p>Note that {@link #refresh()} must be called in order for the context
	 * to fully process the new classes.
	 * @param annotatedClasses one or more annotated classes,
	 * e.g. {@link Configuration @Configuration} classes
	 * @see #scan(String...)
	 * @see #refresh()
	 */
	public void register(Class<?>... annotatedClasses) {
		Assert.notEmpty(annotatedClasses, "At least one annotated class must be specified");
		this.reader.register(annotatedClasses);
	}

	
Perform a scan within the specified base packages.

Note that AbstractApplicationContext.refresh() must be called in order for the context to fully process the new classes. 
Params:
  • basePackages – the packages to check for annotated classes
See Also:
/**
	 * Perform a scan within the specified base packages.
	 * <p>Note that {@link #refresh()} must be called in order for the context
	 * to fully process the new classes.
	 * @param basePackages the packages to check for annotated classes
	 * @see #register(Class...)
	 * @see #refresh()
	 */
	public void scan(String... basePackages) {
		Assert.notEmpty(basePackages, "At least one base package must be specified");
		this.scanner.scan(basePackages);
	}


	//---------------------------------------------------------------------
	// Convenient methods for registering individual beans
	//---------------------------------------------------------------------

	
Register a bean from the given bean class, deriving its metadata from
class-declared annotations, and optionally providing explicit constructor
arguments for consideration in the autowiring process.

The bean name will be generated according to annotated component rules.

Params:
  • annotatedClass – the class of the bean
  • constructorArguments – argument values to be fed into Spring's constructor resolution algorithm, resolving either all arguments or just specific ones, with the rest to be resolved through regular autowiring (may be null or empty)
Since:5.0
/**
	 * Register a bean from the given bean class, deriving its metadata from
	 * class-declared annotations, and optionally providing explicit constructor
	 * arguments for consideration in the autowiring process.
	 * <p>The bean name will be generated according to annotated component rules.
	 * @param annotatedClass the class of the bean
	 * @param constructorArguments argument values to be fed into Spring's
	 * constructor resolution algorithm, resolving either all arguments or just
	 * specific ones, with the rest to be resolved through regular autowiring
	 * (may be {@code null} or empty)
	 * @since 5.0
	 */
	public <T> void registerBean(Class<T> annotatedClass, Object... constructorArguments) {
		registerBean(null, annotatedClass, constructorArguments);
	}

	
Register a bean from the given bean class, deriving its metadata from
class-declared annotations, and optionally providing explicit constructor
arguments for consideration in the autowiring process.

Params:
  • beanName – the name of the bean (may be null)
  • annotatedClass – the class of the bean
  • constructorArguments – argument values to be fed into Spring's constructor resolution algorithm, resolving either all arguments or just specific ones, with the rest to be resolved through regular autowiring (may be null or empty)
Since:5.0
/**
	 * Register a bean from the given bean class, deriving its metadata from
	 * class-declared annotations, and optionally providing explicit constructor
	 * arguments for consideration in the autowiring process.
	 * @param beanName the name of the bean (may be {@code null})
	 * @param annotatedClass the class of the bean
	 * @param constructorArguments argument values to be fed into Spring's
	 * constructor resolution algorithm, resolving either all arguments or just
	 * specific ones, with the rest to be resolved through regular autowiring
	 * (may be {@code null} or empty)
	 * @since 5.0
	 */
	public <T> void registerBean(@Nullable String beanName, Class<T> annotatedClass, Object... constructorArguments) {
		this.reader.doRegisterBean(annotatedClass, null, beanName, null,
				bd -> {
					for (Object arg : constructorArguments) {
						bd.getConstructorArgumentValues().addGenericArgumentValue(arg);
					}
				});
	}

	@Override
	public <T> void registerBean(@Nullable String beanName, Class<T> beanClass, @Nullable Supplier<T> supplier,
			BeanDefinitionCustomizer... customizers) {

		this.reader.doRegisterBean(beanClass, supplier, beanName, null, customizers);
	}

}