public class YamlMapFactoryBean extends YamlProcessor implements FactoryBean<Map<String,Object>>, InitializingBean
Map
that reads from a YAML source, preserving the
YAML-declared value types and their structure.
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: fourplus (later in the list)
foo: bar: one: 2 five: sixresults in an effective input of
foo: bar: one: 2 three: four five: sixNote 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.
Requires SnakeYAML 1.18 or higher, as of Spring Framework 5.0.6.
YamlProcessor.DocumentMatcher, YamlProcessor.MatchCallback, YamlProcessor.MatchStatus, YamlProcessor.ResolutionMethod
OBJECT_TYPE_ATTRIBUTE
Constructor and Description |
---|
YamlMapFactoryBean() |
Modifier and Type | Method and Description |
---|---|
void |
afterPropertiesSet()
Invoked by the containing
BeanFactory after it has set all bean properties
and satisfied BeanFactoryAware , ApplicationContextAware etc. |
protected Map<String,Object> |
createMap()
Template method that subclasses may override to construct the object
returned by this factory.
|
Map<String,Object> |
getObject()
Return an instance (possibly shared or independent) of the object
managed by this factory.
|
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)? |
void |
setSingleton(boolean singleton)
Set if a singleton should be created, or a new object on each request
otherwise.
|
createYaml, getFlattenedMap, process, setDocumentMatchers, setMatchDefault, setResolutionMethod, setResources, setSupportedTypes
public void setSingleton(boolean singleton)
true
(a singleton).public boolean isSingleton()
FactoryBean
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
.
The default implementation returns true
, since a
FactoryBean
typically manages a singleton instance.
isSingleton
in interface FactoryBean<Map<String,Object>>
FactoryBean.getObject()
,
SmartFactoryBean.isPrototype()
public void afterPropertiesSet()
InitializingBean
BeanFactory
after it has set all bean properties
and satisfied BeanFactoryAware
, ApplicationContextAware
etc.
This method allows the bean instance to perform validation of its overall configuration and final initialization when all bean properties have been set.
afterPropertiesSet
in interface InitializingBean
@Nullable public Map<String,Object> getObject()
FactoryBean
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.
getObject
in interface FactoryBean<Map<String,Object>>
null
)FactoryBeanNotInitializedException
public Class<?> getObjectType()
FactoryBean
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.
getObjectType
in interface FactoryBean<Map<String,Object>>
null
if not known at the time of the callListableBeanFactory.getBeansOfType(java.lang.Class<T>)
protected Map<String,Object> createMap()
Invoked lazily the first time getObject()
is invoked in
case of a shared singleton; else, on each getObject()
call.
The default implementation returns the merged Map
instance.
YamlProcessor.process(MatchCallback)