org.springframework.beans.factory.config

Class YamlMapFactoryBean

java.lang.Object

org.springframework.beans.factory.config.YamlProcessor

org.springframework.beans.factory.config.YamlMapFactoryBean

All Implemented Interfaces:

FactoryBean<java.util.Map<java.lang.String,java.lang.Object>>, InitializingBean

public class YamlMapFactoryBean
extends YamlProcessor
implements FactoryBean<java.util.Map<java.lang.String,java.lang.Object>>, InitializingBean

Factory for a Map that reads from a YAML source. YAML is a nice human-readable format for configuration, and it has some useful hierarchical properties. It's more or less a superset of JSON, so it has a lot of similar features. If multiple resources are provided the later ones will override entries in the earlier ones hierarchically - that is all entries with the same nested key of type Map at any depth are merged. For example:

 foo:
   bar:
    one: two
 three: four
 

plus (later in the list)

 foo:
   bar:
    one: 2
 five: six
 

results in an effective input of

 foo:
   bar:
    one: 2
 three: four
 five: six
 

Note that the value of "foo" in the first document is not simply replaced with the value in the second, but its nested values are merged.

Since:

4.1

Author:

Dave Syer

Nested Class Summary

Nested classes/interfaces inherited from class org.springframework.beans.factory.config.YamlProcessor

YamlProcessor.DocumentMatcher, YamlProcessor.MatchCallback, YamlProcessor.MatchStatus, YamlProcessor.ResolutionMethod, YamlProcessor.StrictMapAppenderConstructor

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.Map<java.lang.String,java.lang.Object>	map
private boolean	singleton

Constructor Summary

Constructors

Constructor and Description
YamlMapFactoryBean()

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet() Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected java.util.Map<java.lang.String,java.lang.Object>	createMap() Template method that subclasses may override to construct the object returned by this factory.
java.util.Map<java.lang.String,java.lang.Object>	getObject() Return an instance (possibly shared or independent) of the object managed by this factory.
java.lang.Class<?>	getObjectType() Return the type of object that this FactoryBean creates, or null if not known in advance.
boolean	isSingleton() Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?
private void	merge(java.util.Map<java.lang.String,java.lang.Object> output, java.util.Map<java.lang.String,java.lang.Object> map)
void	setSingleton(boolean singleton) Set if a singleton should be created, or a new object on each request otherwise.

Methods inherited from class org.springframework.beans.factory.config.YamlProcessor

createYaml, getFlattenedMap, process, setDocumentMatchers, setMatchDefault, setResolutionMethod, setResources

Methods inherited from class java.lang.Object

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

Field Detail

singleton

private boolean singleton

map

private java.util.Map<java.lang.String,java.lang.Object> map

Constructor Detail

YamlMapFactoryBean

public YamlMapFactoryBean()

Method Detail

setSingleton

public void setSingleton(boolean singleton)

Set if a singleton should be created, or a new object on each request otherwise. Default is true (a singleton).

isSingleton

public boolean isSingleton()

Description copied from interface: FactoryBean

Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?

NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from getObject() might get cached by the owning BeanFactory. Hence, do not return true unless the FactoryBean always exposes the same reference.

The singleton status of the FactoryBean itself will generally be provided by the owning BeanFactory; usually, it has to be defined as singleton there.

NOTE: This method returning false does not necessarily indicate that returned objects are independent instances. An implementation of the extended SmartFactoryBean interface may explicitly indicate independent instances through its SmartFactoryBean.isPrototype() method. Plain FactoryBean implementations which do not implement this extended interface are simply assumed to always return independent instances if the isSingleton() implementation returns false.

Specified by:

isSingleton in interface FactoryBean<java.util.Map<java.lang.String,java.lang.Object>>

Returns:

whether the exposed object is a singleton

See Also:

FactoryBean.getObject(), SmartFactoryBean.isPrototype()

afterPropertiesSet

public void afterPropertiesSet()

Description copied from interface: InitializingBean

Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:

afterPropertiesSet in interface InitializingBean

getObject

public java.util.Map<java.lang.String,java.lang.Object> getObject()

Description copied from interface: FactoryBean

Return an instance (possibly shared or independent) of the object managed by this factory.

As with a BeanFactory, this allows support for both the Singleton and Prototype design pattern.

If this FactoryBean is not fully initialized yet at the time of the call (for example because it is involved in a circular reference), throw a corresponding FactoryBeanNotInitializedException.

As of Spring 2.0, FactoryBeans are allowed to return null objects. The factory will consider this as normal value to be used; it will not throw a FactoryBeanNotInitializedException in this case anymore. FactoryBean implementations are encouraged to throw FactoryBeanNotInitializedException themselves now, as appropriate.

Specified by:

getObject in interface FactoryBean<java.util.Map<java.lang.String,java.lang.Object>>

Returns:

an instance of the bean (can be null)

See Also:

FactoryBeanNotInitializedException

getObjectType

public java.lang.Class<?> getObjectType()

Description copied from interface: FactoryBean

Return the type of object that this FactoryBean creates, or null if not known in advance.

This allows one to check for specific types of beans without instantiating objects, for example on autowiring.

In the case of implementations that are creating a singleton object, this method should try to avoid singleton creation as far as possible; it should rather estimate the type in advance. For prototypes, returning a meaningful type here is advisable too.

This method can be called before this FactoryBean has been fully initialized. It must not rely on state created during initialization; of course, it can still use such state if available.

NOTE: Autowiring will simply ignore FactoryBeans that return null here. Therefore it is highly recommended to implement this method properly, using the current state of the FactoryBean.

Specified by:

getObjectType in interface FactoryBean<java.util.Map<java.lang.String,java.lang.Object>>

Returns:

the type of object that this FactoryBean creates, or null if not known at the time of the call

See Also:

ListableBeanFactory.getBeansOfType(java.lang.Class<T>)

createMap

protected java.util.Map<java.lang.String,java.lang.Object> createMap()

Template method that subclasses may override to construct the object returned by this factory. The default implementation returns the merged Map instance.

Invoked lazily the first time getObject() is invoked in case of a shared singleton; else, on each getObject() call.

Returns:

the object returned by this factory

See Also:

YamlProcessor.process(java.util.Map, MatchCallback)

merge

private void merge(java.util.Map<java.lang.String,java.lang.Object> output,
                   java.util.Map<java.lang.String,java.lang.Object> map)