Class ReloadingFileBasedConfigurationBuilder<T extends FileBasedConfiguration>
- Type Parameters:
T
- the concrete type ofConfiguration
objects created by this builder
- All Implemented Interfaces:
ConfigurationBuilder<T>
,EventSource
,ReloadingControllerSupport
A specialized ConfigurationBuilder
implementation which can handle configurations read from a
FileHandler
and supports reloading.
This builder class exposes a ReloadingController
object controlling reload operations on the file-based
configuration produced as result object. For the FileHandler
defining the location of the configuration a
configurable ReloadingDetector
is created and associated with the controller. So changes on the source file
can be detected. When ever such a change occurs, the result object of this builder is reset. This means that the next
time getConfiguration()
is called a new Configuration
object is created which is loaded from the
modified file.
Client code interested in notifications can register a listener at this builder to receive reset events. When such an
event is received the new result object can be requested. This way client applications can be sure to work with an
up-to-date configuration. It is also possible to register a listener directly at the ReloadingController
.
This builder does not actively trigger the ReloadingController
to perform a reload check. This has to be done
by an external component, e.g. a timer.
- Since:
- 2.0
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Constructor Summary
ConstructorDescriptionReloadingFileBasedConfigurationBuilder
(Class<? extends T> resCls) Creates a new instance ofReloadingFileBasedConfigurationBuilder
which produces result objects of the specified class.Creates a new instance ofReloadingFileBasedConfigurationBuilder
which produces result objects of the specified class and sets initialization parameters.ReloadingFileBasedConfigurationBuilder
(Class<? extends T> resCls, Map<String, Object> params, boolean allowFailOnInit) Creates a new instance ofReloadingFileBasedConfigurationBuilder
which produces result objects of the specified class and sets initialization parameters and the allowFailOnInit flag. -
Method Summary
Modifier and TypeMethodDescriptionconfigure
(BuilderParameters... params) Appends the content of the specifiedBuilderParameters
objects to the current initialization parameters.protected ReloadingDetector
createReloadingDetector
(FileHandler handler, FileBasedBuilderParametersImpl fbparams) Creates aReloadingDetector
which monitors the passed inFileHandler
.Gets theReloadingController
associated with this builder.protected void
initFileHandler
(FileHandler handler) Initializes the new currentFileHandler
.Methods inherited from class org.apache.commons.configuration2.builder.FileBasedConfigurationBuilder
getDefaultEncoding, getFileHandler, initResultInstance, isAutoSave, save, setAutoSave, setDefaultEncoding, setParameters
Methods inherited from class org.apache.commons.configuration2.builder.BasicConfigurationBuilder
addEventListener, addParameters, connectToReloadingController, copyEventListeners, copyEventListeners, createResult, createResultDeclaration, createResultInstance, fetchBeanHelper, fireBuilderEvent, getConfiguration, getParameters, getResultClass, getResultDeclaration, installEventListener, isAllowFailOnInit, removeEventListener, reset, resetParameters, resetResult
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Constructor Details
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ReloadingFileBasedConfigurationBuilder
Creates a new instance ofReloadingFileBasedConfigurationBuilder
which produces result objects of the specified class.- Parameters:
resCls
- the result class (must not be null- Throws:
IllegalArgumentException
- if the result class is null
-
ReloadingFileBasedConfigurationBuilder
Creates a new instance ofReloadingFileBasedConfigurationBuilder
which produces result objects of the specified class and sets initialization parameters.- Parameters:
resCls
- the result class (must not be nullparams
- a map with initialization parameters- Throws:
IllegalArgumentException
- if the result class is null
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ReloadingFileBasedConfigurationBuilder
public ReloadingFileBasedConfigurationBuilder(Class<? extends T> resCls, Map<String, Object> params, boolean allowFailOnInit) Creates a new instance ofReloadingFileBasedConfigurationBuilder
which produces result objects of the specified class and sets initialization parameters and the allowFailOnInit flag.- Parameters:
resCls
- the result class (must not be nullparams
- a map with initialization parametersallowFailOnInit
- the allowFailOnInit flag- Throws:
IllegalArgumentException
- if the result class is null
-
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Method Details
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configure
Appends the content of the specifiedBuilderParameters
objects to the current initialization parameters. Calling this method multiple times will create a union of the parameters provided. This method is overridden here to change the result type. This method is overridden here to change the result type.- Overrides:
configure
in classFileBasedConfigurationBuilder<T extends FileBasedConfiguration>
- Parameters:
params
- an arbitrary number of objects with builder parameters- Returns:
- a reference to this builder for method chaining
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createReloadingDetector
protected ReloadingDetector createReloadingDetector(FileHandler handler, FileBasedBuilderParametersImpl fbparams) throws ConfigurationException Creates aReloadingDetector
which monitors the passed inFileHandler
. This method is called each time a new result object is created with the currentFileHandler
. This implementation checks whether aReloadingDetectorFactory
is specified in the current parameters. If this is the case, it is invoked. Otherwise, a default factory is used to create aFileHandlerReloadingDetector
object. Note: This method is called from a synchronized block.- Parameters:
handler
- the currentFileHandler
fbparams
- the object with parameters related to file-based builders- Returns:
- a
ReloadingDetector
for thisFileHandler
- Throws:
ConfigurationException
- if an error occurs
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getReloadingController
Gets theReloadingController
associated with this builder. This controller is directly created. However, it becomes active (i.e. associated with a meaningful reloading detector) not before a result object was created.- Specified by:
getReloadingController
in interfaceReloadingControllerSupport
- Returns:
- the
ReloadingController
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initFileHandler
Initializes the new currentFileHandler
. When a new result object is created, a newFileHandler
is created, too, and associated with the result object. This new handler is passed to this method. If a location is defined, the result object is loaded from this location. Note: This method is called from a synchronized block. This implementation also takes care that a newReloadingDetector
for the new currentFileHandler
is created. Also, the reloading controller's reloading state has to be reset; after the creation of a new result object changes in the underlying configuration source have to be monitored again.- Overrides:
initFileHandler
in classFileBasedConfigurationBuilder<T extends FileBasedConfiguration>
- Parameters:
handler
- the new currentFileHandler
- Throws:
ConfigurationException
- if an error occurs
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