com.netflix.config

Class ConcurrentCompositeConfiguration

java.lang.Object

org.apache.commons.configuration.event.EventSource

org.apache.commons.configuration.AbstractConfiguration

com.netflix.config.ConcurrentMapConfiguration

com.netflix.config.ConcurrentCompositeConfiguration

All Implemented Interfaces:

AggregatedConfiguration, java.lang.Cloneable, org.apache.commons.configuration.Configuration, org.apache.commons.configuration.event.ConfigurationListener

public class ConcurrentCompositeConfiguration
extends ConcurrentMapConfiguration
implements AggregatedConfiguration, org.apache.commons.configuration.event.ConfigurationListener, java.lang.Cloneable

This class maintains a hierarchy of configurations in a list structure. The order of the list stands for the descending priority of the configurations when a property value is to be determined. For example, if you add Configuration1, and then Configuration2, getProperty(String) will return any properties defined by Configuration1. Only if Configuration1 doesn't have the property, then Configuration2 will be checked.

There are two internal configurations for properties that are programmatically set:

• Configuration to hold any property introduced by addProperty(String, Object) or setProperty(String, Object) called directly on this class. This configuration will be called "container configuration" as it serves as the container of such properties. By default, this configuration remains at the last of the configurations list. It can be treated as a "base line" configuration that holds hard-coded parameters that can be overridden by any of other configurations added at runtime. You can replace this configuration by your own and change the position of the configuration in the list by calling setContainerConfiguration(AbstractConfiguration, String, int).
• Configuration to hold properties that are programmatically set (using setOverrideProperty(String, Object)) to override values from any other configurations on the list. As contrast to container configuration, this configuration is always consulted first in getProperty(String).

When adding configuration to this class, it is recommended to convert it into ConcurrentMapConfiguration or ConcurrentCompositeConfiguration using ConfigurationUtils to achieve maximal performance and thread safety.

Example:

   // configuration from local properties file
  String fileName = "...";
  ConcurrentMapConfiguration configFromPropertiesFile =
      new ConcurrentMapConfiguration(new PropertiesConfiguration(fileName));
  // configuration from system properties
  ConcurrentMapConfiguration configFromSystemProperties = 
      new ConcurrentMapConfiguration(new SystemConfiguration());
  // configuration from a dynamic source
  PolledConfigurationSource source = createMyOwnSource();
  AbstractPollingScheduler scheduler = createMyOwnScheduler();
  DynamicConfiguration dynamicConfiguration =
      new DynamicConfiguration(source, scheduler);

  // create a hierarchy of configuration that makes
  // 1) dynamic configuration source override system properties and,
  // 2) system properties override properties file
  ConcurrentCompositeConfiguration finalConfig = new ConcurrentCompositeConfiguration();
  finalConfig.add(dynamicConfiguration, "dynamicConfig");
  finalConfig.add(configFromSystemProperties, "systemConfig");
  finalConfig.add(configFromPropertiesFile, "fileConfig");

  // register with DynamicPropertyFactory so that finalConfig
  // becomes the source of dynamic properties
  DynamicPropertyFactory.initWithConfigurationSource(finalConfig);    
 

Field Summary

Fields

Modifier and Type	Field and Description
static int	EVENT_CONFIGURATION_SOURCE_CHANGED

Fields inherited from class com.netflix.config.ConcurrentMapConfiguration

DISABLE_DELIMITER_PARSING, map

Fields inherited from class org.apache.commons.configuration.AbstractConfiguration

END_TOKEN, EVENT_ADD_PROPERTY, EVENT_CLEAR, EVENT_CLEAR_PROPERTY, EVENT_READ_PROPERTY, EVENT_SET_PROPERTY, START_TOKEN

Constructor Summary

Constructors

Constructor and Description
ConcurrentCompositeConfiguration() Creates an empty CompositeConfiguration object which can then be added some other Configuration files
ConcurrentCompositeConfiguration(org.apache.commons.configuration.AbstractConfiguration containerConfiguration) Creates a ConcurrentCompositeConfiguration object with a specified container configuration.
ConcurrentCompositeConfiguration(org.apache.commons.configuration.AbstractConfiguration containerConfiguration, java.util.Collection<? extends org.apache.commons.configuration.AbstractConfiguration> configurations) Creates a ConcurrentCompositeConfiguration with a specified container configuration, and then adds the given collection of configurations.

Method Summary

Methods

Modifier and Type	Method and Description
void	addConfiguration(org.apache.commons.configuration.AbstractConfiguration config) Add a child configuration without a name.
void	addConfiguration(org.apache.commons.configuration.AbstractConfiguration config, java.lang.String name) Adds a new child configuration to this configuration with an optional name.
void	addConfigurationAtFront(org.apache.commons.configuration.AbstractConfiguration config, java.lang.String name)
void	addConfigurationAtIndex(org.apache.commons.configuration.AbstractConfiguration config, java.lang.String name, int index) Add a configuration with a name at a particular index.
void	addProperty(java.lang.String key, java.lang.Object value) Add the property with the container configuration.
void	clear() Removes all child configurations and reinitializes the container configuration.
void	clearOverrideProperty(java.lang.String key) Remove the overriding property set by setOverrideProperty(String, Object)
void	clearProperty(java.lang.String key) Clear the property with the container configuration.
java.lang.Object	clone() Returns a copy of this object.
void	configurationChanged(org.apache.commons.configuration.event.ConfigurationEvent event) Event listener call back for configuration update events.
boolean	containsKey(java.lang.String key) Check if the any of the sub configurations contains the specified key.
org.apache.commons.configuration.Configuration	getConfiguration(int index) Return the configuration at the specified index.
org.apache.commons.configuration.Configuration	getConfiguration(java.lang.String name) Returns the configuration with the given name.
java.util.List<java.lang.String>	getConfigurationNameList()
java.util.Set<java.lang.String>	getConfigurationNames() Returns a set with the names of all configurations contained in this configuration.
java.util.List<org.apache.commons.configuration.AbstractConfiguration>	getConfigurations() Get the configurations added.
org.apache.commons.configuration.Configuration	getContainerConfiguration() Returns the container configuration In this configuration changes are stored.
int	getIndexOfConfiguration(org.apache.commons.configuration.AbstractConfiguration config)
int	getIndexOfContainerConfiguration()
java.util.Iterator<java.lang.String>	getKeys() Get all the keys contained by sub configurations.
java.util.Iterator<java.lang.String>	getKeys(java.lang.String prefix) Get the list of the keys contained in the sub configurations that match the specified prefix.
java.util.List	getList(java.lang.String key, java.util.List defaultValue) Get a List of objects associated with the given configuration key.
int	getNumberOfConfigurations() Return the number of configurations.
java.lang.Object	getProperty(java.lang.String key) Read property from underlying composite.
org.apache.commons.configuration.Configuration	getSource(java.lang.String key) Returns the configuration source, in which the specified key is defined.
java.lang.String[]	getStringArray(java.lang.String key) Get an array of strings associated with the given configuration key.
void	invalidate()
boolean	isEmpty()
boolean	isPropagateEventFromSubConfigurations() Return whether sub configurations should propagate events to listeners to this configuration.
boolean	removeConfiguration(org.apache.commons.configuration.Configuration config) Remove a configuration.
org.apache.commons.configuration.Configuration	removeConfiguration(java.lang.String name) Removes the configuration with the specified name.
org.apache.commons.configuration.AbstractConfiguration	removeConfigurationAt(int index)
void	setContainerConfiguration(org.apache.commons.configuration.AbstractConfiguration config, java.lang.String name, int index) Adds a child configuration and makes it the container configuration.
void	setContainerConfigurationIndex(int newIndex) Change the position of the container configuration to a new index.
void	setDelimiterParsingDisabled(boolean delimiterParsingDisabled) Sets a flag whether added values for string properties should be checked for the list delimiter.
void	setListDelimiter(char listDelimiter) Sets the character that is used as list delimiter.
void	setOverrideProperty(java.lang.String key, java.lang.Object finalValue) Override the same property in any other configurations in the list.
void	setPropagateEventFromSubConfigurations(boolean propagateEventToParent) Set whether sub configurations should propagate events to listeners to this configuration.
void	setProperty(java.lang.String key, java.lang.Object value) Set the property with the container configuration.

Methods inherited from class com.netflix.config.ConcurrentMapConfiguration

addConfigurationListener, addErrorListener, addPropertyDirect, addPropertyImpl, clearConfigurationListeners, clearErrorListeners, clearPropertyDirect, copy, fireError, fireEvent, getConfigurationListeners, getErrorListeners, getProperties, loadProperties, removeConfigurationListener, removeErrorListener, setPropertyImpl

Methods inherited from class org.apache.commons.configuration.AbstractConfiguration

addErrorLogListener, append, createInterpolator, getBigDecimal, getBigDecimal, getBigInteger, getBigInteger, getBoolean, getBoolean, getBoolean, getByte, getByte, getByte, getDefaultListDelimiter, getDelimiter, getDouble, getDouble, getDouble, getFloat, getFloat, getFloat, getInt, getInt, getInteger, getInterpolator, getList, getListDelimiter, getLogger, getLong, getLong, getLong, getProperties, getProperties, getShort, getShort, getShort, getString, getString, getSubstitutor, interpolate, interpolate, interpolatedConfiguration, interpolateHelper, isDelimiterParsingDisabled, isScalarValue, isThrowExceptionOnMissing, resolveContainerStore, setDefaultListDelimiter, setDelimiter, setLogger, setThrowExceptionOnMissing, subset

Methods inherited from class org.apache.commons.configuration.event.EventSource

createErrorEvent, createEvent, isDetailEvents, setDetailEvents

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.configuration.Configuration

getBigDecimal, getBigDecimal, getBigInteger, getBigInteger, getBoolean, getBoolean, getBoolean, getByte, getByte, getByte, getDouble, getDouble, getDouble, getFloat, getFloat, getFloat, getInt, getInt, getInteger, getList, getLong, getLong, getLong, getProperties, getShort, getShort, getShort, getString, getString, subset

Field Detail

EVENT_CONFIGURATION_SOURCE_CHANGED

public static final int EVENT_CONFIGURATION_SOURCE_CHANGED

See Also:

Constant Field Values

Constructor Detail

ConcurrentCompositeConfiguration

public ConcurrentCompositeConfiguration()

Creates an empty CompositeConfiguration object which can then be added some other Configuration files

ConcurrentCompositeConfiguration

public ConcurrentCompositeConfiguration(org.apache.commons.configuration.AbstractConfiguration containerConfiguration)

Creates a ConcurrentCompositeConfiguration object with a specified container configuration. This configuration will store any changes made by setProperty(String, Object) and addProperty(String, Object).

Parameters:

containerConfiguration - the configuration to use as container configuration

ConcurrentCompositeConfiguration

public ConcurrentCompositeConfiguration(org.apache.commons.configuration.AbstractConfiguration containerConfiguration,
                                java.util.Collection<? extends org.apache.commons.configuration.AbstractConfiguration> configurations)

Creates a ConcurrentCompositeConfiguration with a specified container configuration, and then adds the given collection of configurations.

Parameters:

containerConfiguration - container configuration to use

configurations - the collection of configurations to add

Method Detail

configurationChanged

public void configurationChanged(org.apache.commons.configuration.event.ConfigurationEvent event)

Event listener call back for configuration update events. This method is called whenever one of the contained configurations was modified. This method does nothing.

Specified by:

configurationChanged in interface org.apache.commons.configuration.event.ConfigurationListener

Parameters:

event - the update event

invalidate

public void invalidate()

addConfiguration

public final void addConfiguration(org.apache.commons.configuration.AbstractConfiguration config)

Add a child configuration without a name. Make a call to addConfiguration(AbstractConfiguration, String) with the name being null.

Specified by:

addConfiguration in interface AggregatedConfiguration

Parameters:

config - the configuration to add

addConfiguration

public void addConfiguration(org.apache.commons.configuration.AbstractConfiguration config,
                    java.lang.String name)

Adds a new child configuration to this configuration with an optional name. The configuration will be added to the end of the list if container configuration has been changed to new one or no longer at the end of the list. Otherwise it will be added in front of the container configuration.

Specified by:

addConfiguration in interface AggregatedConfiguration

Parameters:

config - the configuration to add (must not be null)

name - the name of this configuration (can be null)

getConfigurations

public java.util.List<org.apache.commons.configuration.AbstractConfiguration> getConfigurations()

Get the configurations added.

Specified by:

getConfigurations in interface AggregatedConfiguration

getConfigurationNameList

public java.util.List<java.lang.String> getConfigurationNameList()

Specified by:

getConfigurationNameList in interface AggregatedConfiguration

getIndexOfConfiguration

public int getIndexOfConfiguration(org.apache.commons.configuration.AbstractConfiguration config)

getIndexOfContainerConfiguration

public int getIndexOfContainerConfiguration()

setContainerConfiguration

public void setContainerConfiguration(org.apache.commons.configuration.AbstractConfiguration config,
                             java.lang.String name,
                             int index)
                               throws java.lang.IndexOutOfBoundsException

Adds a child configuration and makes it the container configuration. This means that all future property write operations are executed on this configuration. Note that the current container configuration stays in the list of child configurations at its current position, but it passes its role as container configuration to the new one.

Parameters:

config - the configuration to be added

name - the name of the configuration to be added

index - index to add this configuration

Throws:

java.lang.IndexOutOfBoundsException

setContainerConfigurationIndex

public void setContainerConfigurationIndex(int newIndex)
                                    throws java.lang.IndexOutOfBoundsException

Change the position of the container configuration to a new index.

Throws:

java.lang.IndexOutOfBoundsException

addConfigurationAtIndex

public void addConfigurationAtIndex(org.apache.commons.configuration.AbstractConfiguration config,
                           java.lang.String name,
                           int index)
                             throws java.lang.IndexOutOfBoundsException

Add a configuration with a name at a particular index.

Throws:

java.lang.IndexOutOfBoundsException

addConfigurationAtFront

public void addConfigurationAtFront(org.apache.commons.configuration.AbstractConfiguration config,
                           java.lang.String name)

removeConfiguration

public boolean removeConfiguration(org.apache.commons.configuration.Configuration config)

Remove a configuration. The container configuration cannot be removed.

Specified by:

removeConfiguration in interface AggregatedConfiguration

Parameters:

config - The configuration to remove

removeConfigurationAt

public org.apache.commons.configuration.AbstractConfiguration removeConfigurationAt(int index)

Specified by:

removeConfigurationAt in interface AggregatedConfiguration

removeConfiguration

public org.apache.commons.configuration.Configuration removeConfiguration(java.lang.String name)

Removes the configuration with the specified name.

Specified by:

removeConfiguration in interface AggregatedConfiguration

Parameters:

name - the name of the configuration to be removed

Returns:

the removed configuration (null if this configuration was not found)

getNumberOfConfigurations

public int getNumberOfConfigurations()

Return the number of configurations.

Specified by:

getNumberOfConfigurations in interface AggregatedConfiguration

Returns:

the number of configuration

clear

public final void clear()

Removes all child configurations and reinitializes the container configuration. Attention: A new container configuration is created; the old one is lost.

Specified by:

clear in interface org.apache.commons.configuration.Configuration

Overrides:

clear in class ConcurrentMapConfiguration

setOverrideProperty

public void setOverrideProperty(java.lang.String key,
                       java.lang.Object finalValue)

Override the same property in any other configurations in the list.

clearOverrideProperty

public void clearOverrideProperty(java.lang.String key)

Remove the overriding property set by setOverrideProperty(String, Object)

setProperty

public void setProperty(java.lang.String key,
               java.lang.Object value)

Set the property with the container configuration. Warning: getProperty(String) on this key may not return the same value set by this method if there is any other configuration that contain the same property and is in front of the container configuration in the configurations list.

Specified by:

setProperty in interface org.apache.commons.configuration.Configuration

Overrides:

setProperty in class ConcurrentMapConfiguration

addProperty

public void addProperty(java.lang.String key,
               java.lang.Object value)

Add the property with the container configuration. Warning: getProperty(String) on this key may not return the same value set by this method if there is any other configuration that contain the same property and is in front of the container configuration in the configurations list.

Specified by:

addProperty in interface org.apache.commons.configuration.Configuration

Overrides:

addProperty in class ConcurrentMapConfiguration

clearProperty

public void clearProperty(java.lang.String key)

Clear the property with the container configuration. Warning: getProperty(String) on this key may still return some value if there is any other configuration that contain the same property and is in front of the container configuration in the configurations list.

Specified by:

clearProperty in interface org.apache.commons.configuration.Configuration

Overrides:

clearProperty in class org.apache.commons.configuration.AbstractConfiguration

getProperty

public java.lang.Object getProperty(java.lang.String key)

Read property from underlying composite. It first checks if the property has been overridden by setOverrideProperty(String, Object) and if so return the overriding value. Otherwise, it iterates through the list of sub configurations until it finds one that contains the property and return the value from that sub configuration. It returns null of the property does not exist.

Specified by:

getProperty in interface org.apache.commons.configuration.Configuration

Overrides:

getProperty in class ConcurrentMapConfiguration

Parameters:

key - key to use for mapping

Returns:

object associated with the given configuration key. null if it does not exist.

getKeys

public java.util.Iterator<java.lang.String> getKeys()
                                             throws java.util.ConcurrentModificationException

Get all the keys contained by sub configurations.

Specified by:

getKeys in interface org.apache.commons.configuration.Configuration

Overrides:

getKeys in class ConcurrentMapConfiguration

Throws:

java.util.ConcurrentModificationException - if concurrent modification happens on any sub configuration when it is iterated to get all the keys

getKeys

public java.util.Iterator<java.lang.String> getKeys(java.lang.String prefix)

Get the list of the keys contained in the sub configurations that match the specified prefix.

Specified by:

getKeys in interface org.apache.commons.configuration.Configuration

Overrides:

getKeys in class org.apache.commons.configuration.AbstractConfiguration

getConfigurationNames

public java.util.Set<java.lang.String> getConfigurationNames()

Returns a set with the names of all configurations contained in this configuration. Of course here are only these configurations listed, for which a name was specified when they were added.

Specified by:

getConfigurationNames in interface AggregatedConfiguration

Returns:

a set with the names of the contained configurations (never null)

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface org.apache.commons.configuration.Configuration

Overrides:

isEmpty in class ConcurrentMapConfiguration

containsKey

public boolean containsKey(java.lang.String key)

Check if the any of the sub configurations contains the specified key.

Specified by:

containsKey in interface org.apache.commons.configuration.Configuration

Overrides:

containsKey in class ConcurrentMapConfiguration

Parameters:

key - the key whose presence in this configuration is to be tested

Returns:

true if the configuration contains a value for this key, false otherwise

getList

public java.util.List getList(java.lang.String key,
                     java.util.List defaultValue)

Get a List of objects associated with the given configuration key. If the key doesn't map to an existing object, the default value is returned.

Specified by:

getList in interface org.apache.commons.configuration.Configuration

Overrides:

getList in class org.apache.commons.configuration.AbstractConfiguration

Parameters:

key - The configuration key.

defaultValue - The default value.

Returns:

The associated List of value.

getStringArray

public java.lang.String[] getStringArray(java.lang.String key)

Get an array of strings associated with the given configuration key. If the key doesn't map to an existing object an empty array is returned

Specified by:

getStringArray in interface org.apache.commons.configuration.Configuration

Overrides:

getStringArray in class org.apache.commons.configuration.AbstractConfiguration

Parameters:

key - The configuration key.

Returns:

The associated string array if key is found.

getConfiguration

public org.apache.commons.configuration.Configuration getConfiguration(int index)

Return the configuration at the specified index.

Specified by:

getConfiguration in interface AggregatedConfiguration

Parameters:

index - The index of the configuration to retrieve

Returns:

the configuration at this index

getConfiguration

public org.apache.commons.configuration.Configuration getConfiguration(java.lang.String name)

Returns the configuration with the given name. This can be null if no such configuration exists.

Specified by:

getConfiguration in interface AggregatedConfiguration

Parameters:

name - the name of the configuration

Returns:

the configuration with this name

getContainerConfiguration

public org.apache.commons.configuration.Configuration getContainerConfiguration()

Returns the container configuration In this configuration changes are stored.

Returns:

the container configuration

clone

public java.lang.Object clone()

Returns a copy of this object. This implementation will create a deep clone, i.e. all configurations contained in this composite will also be cloned. This only works if all contained configurations support cloning; otherwise a runtime exception will be thrown. Registered event handlers won't get cloned.

Overrides:

clone in class org.apache.commons.configuration.event.EventSource

setDelimiterParsingDisabled

public void setDelimiterParsingDisabled(boolean delimiterParsingDisabled)

Sets a flag whether added values for string properties should be checked for the list delimiter. This implementation ensures that the container configuration is correctly initialized.

Overrides:

setDelimiterParsingDisabled in class org.apache.commons.configuration.AbstractConfiguration

Parameters:

delimiterParsingDisabled - the new value of the flag

setListDelimiter

public void setListDelimiter(char listDelimiter)

Sets the character that is used as list delimiter. This implementation ensures that the container configuration is correctly initialized.

Overrides:

setListDelimiter in class org.apache.commons.configuration.AbstractConfiguration

Parameters:

listDelimiter - the new list delimiter character

getSource

public org.apache.commons.configuration.Configuration getSource(java.lang.String key)

Returns the configuration source, in which the specified key is defined. This method will iterate over all existing child configurations and check whether they contain the specified key. The following constellations are possible:

• If the child configurations contains this key, the first one is returned.
• If none of the child configurations contain the key, null is returned.

Parameters:

key - the key to be checked

Returns:

the source configuration of this key

isPropagateEventFromSubConfigurations

public final boolean isPropagateEventFromSubConfigurations()

Return whether sub configurations should propagate events to listeners to this configuration.

setPropagateEventFromSubConfigurations

public final void setPropagateEventFromSubConfigurations(boolean propagateEventToParent)

Set whether sub configurations should propagate events to listeners to this configuration. This is needed if this configuration is used as the configuration source of DynamicPropertyFactory.

Parameters:

propagateEventToParent - value to set