org.springframework.config.java.context
Class JavaConfigApplicationContext

java.lang.Object
  org.springframework.core.io.DefaultResourceLoader
      org.springframework.context.support.AbstractApplicationContext
          org.springframework.context.support.AbstractRefreshableApplicationContext
              org.springframework.config.java.context.JavaConfigApplicationContext

All Implemented Interfaces:

BeanFactory, DisposableBean, HierarchicalBeanFactory, ListableBeanFactory, ApplicationContext, ApplicationEventPublisher, ConfigurableApplicationContext, Lifecycle, MessageSource, ResourceLoader, ResourcePatternResolver

public class JavaConfigApplicationContext
extends AbstractRefreshableApplicationContext

Application context that looks for classes annotated with the Configuration annotation and registers the Beans they define; is the primary programmatic resource for using Spring JavaConfig. Note that it is not strictly required that a configuration class be annotated with @Configuration, but rather that it exposes at least one non-private method annotated with @Bean.

Example

 JavaConfigApplicationContext context = new JavaConfigApplicationContext(AppConfig.class, DataConfig.class);
 
 AccountService accountService = (AccountService) context.getBean("accountService");
 

Where AppConfig and DataConfig are defined as follows:

 @Configuration
 public abstract class AppConfig {
     @Bean
     public AccountService accountService() {
         return new AccountService(dataSource());
     }
     @ExternalBean
     public abstract DataSource dataSource();
 }
 @Configuration
 public abstract class DataConfig {
     @Bean
     public DataSource dataSource() {
         return new DataSource(...);
     }
 }
 

Construction

The eight available constructors for JavaConfigApplicationContext are divided into two categories:

1. Those that leave the context open for further configuration, and require the user to call refresh
   • JavaConfigApplicationContext()
   • JavaConfigApplicationContext(ApplicationContext)
2. Those that leave the context closed for further configuration and do not require refresh
   • JavaConfigApplicationContext(Class...)
   • JavaConfigApplicationContext(String...)
   • JavaConfigApplicationContext(Class[], String[])
   • JavaConfigApplicationContext(ApplicationContext, Class...)
   • JavaConfigApplicationContext(ApplicationContext, String...)
   • JavaConfigApplicationContext(ApplicationContext, Class[], String[])

In the former set, the following code would be valid:

 JavaConfigApplicationContext ctx = new JavaConfigApplicationContext();
 ctx.setConfigClasses(Config1.class, Config2.class);
 ctx.setBaseClasses("com.foo.myapp.config.*");
 ctx.setParent(anotherContext);
 ctx.refresh();
 Service myService = (Service) ctx.getBean("service");
 

Note that the caller must manually invoke refresh to advise the context that configuration is complete. In most cases, users will not want to be burdened with having to remember to do this, so the latter six constructors are provided as conveniences. They each internally call refresh, which means that any subsequent calls to setConfigClasses, setBasePackages or setParent are invalid and will result in an exception. Simply said, after instantiation with one of the convenience constructors, the context is 'closed for configuration':

 JavaConfigApplicationContext ctx = new JavaConfigApplicationContext(Config1.class, Config2.class);
 
 Service myService = (Service) ctx.getBean("service");
 

Type-safe access to beans

To ensure refactorability and avoid string-based bean lookups, it is recommended that users take advantage of JavaConfigApplicationContext's type-safe getBean methods:

• getBean(Class)
• getBean(Class, String)

The examples above become more elegant using these methods:

 JavaConfigApplicationContext ctx = new JavaConfigApplicationContext(Config1.class, Config2.class);
 
 Service myService = ctx.getBean(Service.class); // no casting required!
 

Of course, if multiple beans of type Service exist in the context, the call above becomes ambiguous. Disambiguation can happen in one of two ways:

1. Declare one bean as Primary

    @Configuration
    public class AppConfig {
        @Bean(primary=Primary.TRUE)
        public Service service() {
            return new Service(...);
        }
        @Bean
        public Service testService() {
            return new Service(...);
        }
    }
    

2. Use the name-qualified getBean(Class, String) variant

    JavaConfigApplicationContext ctx = new JavaConfigApplicationContext(Config1.class, Config2.class);
    
    Service testService = ctx.getBean(Service.class, "testService");
    

Author:

Chris Beams

See Also:

Configuration, Bean

Field Summary

Fields inherited from class org.springframework.context.support.AbstractApplicationContext

APPLICATION_EVENT_MULTICASTER_BEAN_NAME, logger, MESSAGE_SOURCE_BEAN_NAME

Fields inherited from interface org.springframework.beans.factory.BeanFactory

FACTORY_BEAN_PREFIX

Fields inherited from interface org.springframework.context.ConfigurableApplicationContext

LOAD_TIME_WEAVER_BEAN_NAME

Fields inherited from interface org.springframework.core.io.support.ResourcePatternResolver

CLASSPATH_ALL_URL_PREFIX

Fields inherited from interface org.springframework.core.io.ResourceLoader

CLASSPATH_URL_PREFIX

Constructor Summary

JavaConfigApplicationContext()
requires calling refresh() TODO: finish doc

JavaConfigApplicationContext(ApplicationContext parent)
requires calling refresh() TODO: finish doc

JavaConfigApplicationContext(ApplicationContext parent, Class<?>... classes)

JavaConfigApplicationContext(ApplicationContext parent, Class<?>[] classes, String[] basePackages)
TODO: Document

JavaConfigApplicationContext(ApplicationContext parent, String... basePackages)

JavaConfigApplicationContext(Class<?>... classes)

JavaConfigApplicationContext(Class<?>[] classes, String[] basePackages)

JavaConfigApplicationContext(String... basePackages)

Method Summary

void	addConfigClass(Class<?> cls) Allows for incrementally building up the configuration classes to be processed by this context.
protected void	finishRefresh()
protected String[]	getBasePackages()
<T> T	getBean(Class<T> type) Return an instance of the given type.
<T> T	getBean(Class<T> type, String beanName) Return an instance named beanName and of type type.
protected Class<?>[]	getConfigClasses()
protected void	loadBeanDefinitions(DefaultListableBeanFactory beanFactory)
protected void	prepareRefresh()
protected void	registerDefaultPostProcessors() Register the default post processors used for parsing Spring classes.
void	setBasePackages(String... basePackages) The base packages for configurations from Strings.
void	setConfigClasses(Class<?>... classes)
void	setParent(ApplicationContext context)

Methods inherited from class org.springframework.context.support.AbstractRefreshableApplicationContext

closeBeanFactory, createBeanFactory, customizeBeanFactory, getBeanFactory, hasBeanFactory, refreshBeanFactory

Methods inherited from class org.springframework.context.support.AbstractApplicationContext

addApplicationListener, addBeanFactoryPostProcessor, addListener, cancelRefresh, close, containsBean, containsBeanDefinition, containsLocalBean, destroy, destroyBeans, doClose, finishBeanFactoryInitialization, getAliases, getApplicationListeners, getAutowireCapableBeanFactory, getBean, getBean, getBean, getBeanDefinitionCount, getBeanDefinitionNames, getBeanFactoryPostProcessors, getBeanNamesForType, getBeanNamesForType, getBeansOfType, getBeansOfType, getDisplayName, getInternalParentBeanFactory, getInternalParentMessageSource, getMessage, getMessage, getMessage, getParent, getParentBeanFactory, getResourcePatternResolver, getResources, getStartupDate, getType, initApplicationEventMulticaster, initLifecycleDependentBeans, initMessageSource, invokeBeanFactoryPostProcessors, isActive, isPrototype, isRunning, isSingleton, isTypeMatch, obtainFreshBeanFactory, onClose, onRefresh, postProcessBeanFactory, prepareBeanFactory, publishEvent, refresh, registerBeanPostProcessors, registerListeners, registerShutdownHook, setDisplayName, start, stop, toString

Methods inherited from class org.springframework.core.io.DefaultResourceLoader

getClassLoader, getResource, getResourceByPath, setClassLoader

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.beans.factory.BeanFactory

containsBean, getAliases, getBean, getBean, getBean, getType, isPrototype, isSingleton, isTypeMatch

Methods inherited from interface org.springframework.core.io.ResourceLoader

getClassLoader, getResource

Constructor Detail

JavaConfigApplicationContext

public JavaConfigApplicationContext()

requires calling refresh() TODO: finish doc

JavaConfigApplicationContext

public JavaConfigApplicationContext(ApplicationContext parent)

requires calling refresh() TODO: finish doc

Parameters:

parent -

JavaConfigApplicationContext

public JavaConfigApplicationContext(String... basePackages)

JavaConfigApplicationContext

public JavaConfigApplicationContext(Class<?>... classes)

JavaConfigApplicationContext

public JavaConfigApplicationContext(ApplicationContext parent,
                                    Class<?>... classes)

JavaConfigApplicationContext

public JavaConfigApplicationContext(ApplicationContext parent,
                                    String... basePackages)

JavaConfigApplicationContext

public JavaConfigApplicationContext(Class<?>[] classes,
                                    String[] basePackages)

JavaConfigApplicationContext

public JavaConfigApplicationContext(ApplicationContext parent,
                                    Class<?>[] classes,
                                    String[] basePackages)

TODO: Document

Parameters:

parent -

classes -

basePackages -

See Also:

prepareRefresh(), finishRefresh()

Method Detail

prepareRefresh

protected void prepareRefresh()

Overrides:

prepareRefresh in class AbstractApplicationContext

setConfigClasses

public void setConfigClasses(Class<?>... classes)

addConfigClass

public void addConfigClass(Class<?> cls)

Allows for incrementally building up the configuration classes to be processed by this context. May only be called on a context still 'open for configuration' meaning that the user will need to manually call refresh() after all classes have been added.

Parameters:

cls -

setBasePackages

public void setBasePackages(String... basePackages)

The base packages for configurations from Strings. These use the same conventions as the component scanning introduced in Spring 2.5.

setParent

public void setParent(ApplicationContext context)

Specified by:

setParent in interface ConfigurableApplicationContext

Overrides:

setParent in class AbstractApplicationContext

getBasePackages

protected String[] getBasePackages()

getConfigClasses

protected Class<?>[] getConfigClasses()

finishRefresh

protected void finishRefresh()

Overrides:

finishRefresh in class AbstractApplicationContext

loadBeanDefinitions

protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory)
                            throws IOException,
                                   BeansException

Specified by:

loadBeanDefinitions in class AbstractRefreshableApplicationContext

Throws:

IOException

BeansException

registerDefaultPostProcessors

protected void registerDefaultPostProcessors()

Register the default post processors used for parsing Spring classes.

See Also:

JavaConfigBeanFactoryPostProcessorRegistry

getBean

public <T> T getBean(Class<T> type)

Return an instance of the given type. If multiple instances of the same type exist, instances are inspected to see if exactly one is marked as Primary

Parameters:

type - desired instance type

Returns:

instance matching type

See Also:

Primary

getBean

public <T> T getBean(Class<T> type,
                     String beanName)

Return an instance named beanName and of type type. Useful in disambiguation cases where there is more than one bean of a given type within the factory and none is marked as Primary

This method is similar to its predecessor BeanFactory.getBean(String, Class), but this variant takes advantages of generics and removes the casting burden from the caller.