Package com.saperion.common.config.loader

Class ChainedPropertiesLoader

java.lang.Object

com.saperion.common.config.loader.AbstractPropertiesLoader

com.saperion.common.config.loader.ChainedPropertiesLoader

All Implemented Interfaces:

PropertiesLoader

public class ChainedPropertiesLoader
extends AbstractPropertiesLoader

The ChainedPropertiesLoader can be used to define a chain of PropertiesLoaders that should be used to load properties. The chain is defined by adding mandatory or optional PropertiesLoaders using the methods addMandatoryPropertiesLoader(PropertiesLoader) and addOptionalPropertiesLoader(PropertiesLoader).

Each PropertiesResource will then be loaded by the registered PropertiesLoaders-chain. The PropertiesLoaders registration order is also being used for loading.

A single Properties object is filled by the returned Properties of each PropertiesLoader in the chain. As a result, properties values by the same key will be overwritten in the returned Properties instance.

Example: The PropertiesLoaders A & B are registered in the stated order. Then load(PropertiesResource) is called on the ChainedPropertiesLoader. Now ChainedPropertiesLoader loops through it's chain: PropertiesLoader A is used to load the PropertiesResource. The returned Properties are temporarily stored in P. PropertiesLoader B is used to load the PropertiesResource. The returned Properties are also stored in P. This possibly overwrites property values with the same key. P is returned by the load(PropertiesResource) method. This is also true for the method loadList(List).

This implementation is not synchronized. If used by different threads concurrently, external synchronization is necessary.

Author:

sts

See Also:

• load(PropertiesResource)
• loadList(List)

Constructor Summary

Constructors

Constructor	Description
ChainedPropertiesLoader()

Method Summary

Modifier and Type	Method	Description
void	addMandatoryPropertiesLoader(PropertiesLoader propertiesLoader)	Registers a mandatory PropertiesLoader.
void	addOptionalPropertiesLoader(PropertiesLoader propertiesLoader)	Registers an optional PropertiesLoader.
Properties	load(PropertiesResource propertiesResource)	Loads one PropertiesResource using the registered PropertiesLoaders.
Properties	loadList(List<? extends PropertiesResource> listPropertiesResources)	Loads the given PropertiesResources by use of the registered PropertiesLoaders.
String	toString()

Methods inherited from class com.saperion.common.config.loader.AbstractPropertiesLoader

loadAsMap

Methods inherited from class java.lang.Object

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

Constructor Details

ChainedPropertiesLoader

public ChainedPropertiesLoader()

Method Details

addMandatoryPropertiesLoader

public void addMandatoryPropertiesLoader(PropertiesLoader propertiesLoader)

Registers a mandatory PropertiesLoader. The registered PropertiesLoader is than used in the method loadList(List). If it than throws a ConfigurationException this exception is re-thrown and the loadList(List)-method is aborted.

The specified PropertiesLoader must not be null.

Parameters:

propertiesLoader - the PropertiesLoader to add.

See Also:

• loadList(List)
• load(PropertiesResource)

addOptionalPropertiesLoader

public void addOptionalPropertiesLoader(PropertiesLoader propertiesLoader)

Registers an optional PropertiesLoader. The registered PropertiesLoader is then used in the method loadList(List). If it than throws a ConfigurationException this exception is ignored but logged with LogLevel.INFO.

The specified PropertiesLoader must not be null.

Parameters:

propertiesLoader - the PropertiesLoader to add.

See Also:

• loadList(List)
• load(PropertiesResource)

load

public Properties load(PropertiesResource propertiesResource)
                throws ConfigurationException

Loads one PropertiesResource using the registered PropertiesLoaders.

The specified PropertiesResource must not be null.

Parameters:

propertiesResource - the PropertiesResource to be load.

Returns:

a Properties instance containing the load properties.

Throws:

ConfigurationException - if a PropertiesResource could not be load by a mandatory PropertiesLoader.

See Also:

• for more information.

loadList

public Properties loadList(List<? extends PropertiesResource> listPropertiesResources)
                    throws ConfigurationException

Loads the given PropertiesResources by use of the registered PropertiesLoaders. If no PropertiesLoaders are registered, an empty Properties instance is returned. If an empty PropertiesResource-List is given, an empty Properties instance is returned. All load properties are returned as one Properties object. As a result, Properties entries with the same key will be overwritten if loaded more than once.

When loading the PropertiesResources the registered PropertiesLoaders are used in the same order as they were registered using the methods addMandatoryPropertiesLoader(PropertiesLoader) or addOptionalPropertiesLoader(PropertiesLoader).

When an optional PropertiesLoader (registered by the method addOptionalPropertiesLoader(PropertiesLoader)) throws a ConfigurationException this exception is ignored but logged with LogLevel.INFO.

When a mandatory PropertiesLoader (registered by the method addMandatoryPropertiesLoader(PropertiesLoader)) throws a ConfigurationException this exception is re-thrown and this method is aborted.

The specified list of PropertiesResources must not be null.

Parameters:

listPropertiesResources - the properties resources to be load.

Returns:

a Properties instance containing the load properties.

Throws:

ConfigurationException - if a PropertiesResource could not be load by a mandatory PropertiesLoader.

toString

public String toString()

Overrides:

toString in class Object