org.springframework.context.support.GenericApplicationContext Maven / Gradle / Ivy
/*
* Copyright 2002-2007 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.support;
import java.io.IOException;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.util.Assert;
/**
* Generic ApplicationContext implementation that holds a single internal
* {@link org.springframework.beans.factory.support.DefaultListableBeanFactory}
* instance and does not assume a specific bean definition format. Implements
* the {@link org.springframework.beans.factory.support.BeanDefinitionRegistry}
* interface in order to allow for applying any bean definition readers to it.
*
* Typical usage is to register a variety of bean definitions via the
* {@link org.springframework.beans.factory.support.BeanDefinitionRegistry}
* interface and then call {@link #refresh()} to initialize those beans
* with application context semantics (handling
* {@link org.springframework.context.ApplicationContextAware}, auto-detecting
* {@link org.springframework.beans.factory.config.BeanFactoryPostProcessor BeanFactoryPostProcessors},
* etc).
*
*
In contrast to other ApplicationContext implementations that create a new
* internal BeanFactory instance for each refresh, the internal BeanFactory of
* this context is available right from the start, to be able to register bean
* definitions on it. {@link #refresh()} may only be called once.
*
*
Usage example:
*
*
* GenericApplicationContext ctx = new GenericApplicationContext();
* XmlBeanDefinitionReader xmlReader = new XmlBeanDefinitionReader(ctx);
* xmlReader.loadBeanDefinitions(new ClassPathResource("applicationContext.xml"));
* PropertiesBeanDefinitionReader propReader = new PropertiesBeanDefinitionReader(ctx);
* propReader.loadBeanDefinitions(new ClassPathResource("otherBeans.properties"));
* ctx.refresh();
*
* MyBean myBean = (MyBean) ctx.getBean("myBean");
* ...
*
* For the typical case of XML bean definitions, simply use
* {@link ClassPathXmlApplicationContext} or {@link FileSystemXmlApplicationContext},
* which are easier to set up - but less flexible, since you can just use standard
* resource locations for XML bean definitions, rather than mixing arbitrary bean
* definition formats. The equivalent in a web environment is
* {@link org.springframework.web.context.support.XmlWebApplicationContext}.
*
* For custom application context implementations that are supposed to read
* special bean definition formats in a refreshable manner, consider deriving
* from the {@link AbstractRefreshableApplicationContext} base class.
*
* @author Juergen Hoeller
* @since 1.1.2
* @see #registerBeanDefinition
* @see #refresh()
* @see org.springframework.beans.factory.xml.XmlBeanDefinitionReader
* @see org.springframework.beans.factory.support.PropertiesBeanDefinitionReader
*/
public class GenericApplicationContext extends AbstractApplicationContext implements BeanDefinitionRegistry {
private final DefaultListableBeanFactory beanFactory;
private ResourceLoader resourceLoader;
private boolean refreshed = false;
/**
* Create a new GenericApplicationContext.
* @see #registerBeanDefinition
* @see #refresh
*/
public GenericApplicationContext() {
this.beanFactory = new DefaultListableBeanFactory();
}
/**
* Create a new GenericApplicationContext with the given DefaultListableBeanFactory.
* @param beanFactory the DefaultListableBeanFactory instance to use for this context
* @see #registerBeanDefinition
* @see #refresh
*/
public GenericApplicationContext(DefaultListableBeanFactory beanFactory) {
Assert.notNull(beanFactory, "BeanFactory must not be null");
this.beanFactory = beanFactory;
}
/**
* Create a new GenericApplicationContext with the given parent.
* @param parent the parent application context
* @see #registerBeanDefinition
* @see #refresh
*/
public GenericApplicationContext(ApplicationContext parent) {
this();
setParent(parent);
}
/**
* Create a new GenericApplicationContext with the given DefaultListableBeanFactory.
* @param beanFactory the DefaultListableBeanFactory instance to use for this context
* @param parent the parent application context
* @see #registerBeanDefinition
* @see #refresh
*/
public GenericApplicationContext(DefaultListableBeanFactory beanFactory, ApplicationContext parent) {
this(beanFactory);
setParent(parent);
}
/**
* Set the parent of this application context, also setting
* the parent of the internal BeanFactory accordingly.
* @see org.springframework.beans.factory.config.ConfigurableBeanFactory#setParentBeanFactory
*/
public void setParent(ApplicationContext parent) {
super.setParent(parent);
this.beanFactory.setParentBeanFactory(getInternalParentBeanFactory());
}
/**
* Set a ResourceLoader to use for this context. If set, the context will
* delegate all getResource calls to the given ResourceLoader.
* If not set, default resource loading will apply.
*
The main reason to specify a custom ResourceLoader is to resolve
* resource paths (withour URL prefix) in a specific fashion.
* The default behavior is to resolve such paths as class path locations.
* To resolve resource paths as file system locations, specify a
* FileSystemResourceLoader here.
*
You can also pass in a full ResourcePatternResolver, which will
* be autodetected by the context and used for getResources
* calls as well. Else, default resource pattern matching will apply.
* @see #getResource
* @see org.springframework.core.io.DefaultResourceLoader
* @see org.springframework.core.io.FileSystemResourceLoader
* @see org.springframework.core.io.support.ResourcePatternResolver
* @see #getResources
*/
public void setResourceLoader(ResourceLoader resourceLoader) {
this.resourceLoader = resourceLoader;
}
/**
* This implementation delegates to this context's ResourceLoader if set,
* falling back to the default superclass behavior else.
* @see #setResourceLoader
*/
public Resource getResource(String location) {
if (this.resourceLoader != null) {
return this.resourceLoader.getResource(location);
}
return super.getResource(location);
}
/**
* This implementation delegates to this context's ResourceLoader if it
* implements the ResourcePatternResolver interface, falling back to the
* default superclass behavior else.
* @see #setResourceLoader
*/
public Resource[] getResources(String locationPattern) throws IOException {
if (this.resourceLoader instanceof ResourcePatternResolver) {
return ((ResourcePatternResolver) this.resourceLoader).getResources(locationPattern);
}
return super.getResources(locationPattern);
}
//---------------------------------------------------------------------
// Implementations of AbstractApplicationContext's template methods
//---------------------------------------------------------------------
/**
* Do nothing: We hold a single internal BeanFactory and rely on callers
* to register beans through our public methods (or the BeanFactory's).
* @see #registerBeanDefinition
*/
protected final void refreshBeanFactory() throws IllegalStateException {
if (this.refreshed) {
throw new IllegalStateException(
"GenericApplicationContext does not support multiple refresh attempts: just call 'refresh' once");
}
this.refreshed = true;
}
/**
* Do nothing: We hold a single internal BeanFactory that will never
* get released.
*/
protected final void closeBeanFactory() {
}
/**
* Return the single internal BeanFactory held by this context
* (as ConfigurableListableBeanFactory).
*/
public final ConfigurableListableBeanFactory getBeanFactory() {
return this.beanFactory;
}
/**
* Return the underlying bean factory of this context,
* available for registering bean definitions.
*
NOTE: You need to call {@link #refresh()} to initialize the
* bean factory and its contained beans with application context semantics
* (autodetecting BeanFactoryPostProcessors, etc).
* @return the internal bean factory (as DefaultListableBeanFactory)
*/
public final DefaultListableBeanFactory getDefaultListableBeanFactory() {
return this.beanFactory;
}
//---------------------------------------------------------------------
// Implementation of BeanDefinitionRegistry
//---------------------------------------------------------------------
public BeanDefinition getBeanDefinition(String beanName) throws BeansException {
return this.beanFactory.getBeanDefinition(beanName);
}
public void registerBeanDefinition(String beanName, BeanDefinition beanDefinition) throws BeansException {
this.beanFactory.registerBeanDefinition(beanName, beanDefinition);
}
public void registerAlias(String beanName, String alias) throws BeansException {
this.beanFactory.registerAlias(beanName, alias);
}
}