org.activemath.abstractcontent
Class SubconfImpl.PropertiesConfig

java.lang.Object
  org.activemath.abstractcontent.SubconfImpl.AbstractSubconfiguration
      org.activemath.abstractcontent.SubconfImpl.PropertiesConfig

All Implemented Interfaces:

Subconfiguration

Enclosing class:

SubconfImpl

public static class SubconfImpl.PropertiesConfig
extends SubconfImpl.AbstractSubconfiguration

This class provides the subconfiguration facilities provided by a property file and to create services on a property-file based configuration.

It does so by assuming the following properties in the property file:

• Each service is declared as follows:
• A property service.<some_name>.interfaceName provides the interface class-name that can be provided as getService(java.lang.String) argument. The name <some_name> is a local-name that is meant to be irrelevant to the rest of the applications and is only used to group together the properties of this interface, all property-names for the definition of this service should start with service.<some_name>..
• A property service.<some_name>.className describing the class of the service-object to construct
• If the service-object accepts a constructor with a Subconfiguration, then a one should find service.<some_name>.configPrefix providing the property-name prefix that will be used to create SubconfImpl.ChildSubconfiguration with this object as parent to use in the named constructor (for example, service.<some_name>.config).
• If the service object is meant to be constructed as a bean (i.e. with a blank constructor and with setter-method-names obeying the bean-standards), one should find a service.<some_name>.beanPrefix being the prefix whose children (as obtained by getChildrenNames(java.lang.String)) provide the property-names and whose values provide the values to set the properties of the bean (note that currently, only rudimentary bean-support is provided, i.e. no converters are provided.
• A property service.<some_name>.init indicating the time when the service should be initialized. Either asap or whenNeeded.

This class is not (yet) mutliple-threads aware. Special care should be taken in service initialization with respect to multiple-threads.

Nested Class Summary

static class

SubconfImpl.PropertiesConfig.CyclicServiceInitException An exception denoting the imposibility to initialize services as an infite loop would result instead.

Field Summary

protected Map

services This map has, as keys, the interfaceName (as used in getService(java.lang.String)) and as values either the created service or a String object, the property child-name that defines the service, or this same name followed by " BEING INITTED" if it is being constructed, or a Throwable is the initialization of the service went wrong (it is attempted only once).

Constructor Summary

SubconfImpl.PropertiesConfig(Map props, SubconfImpl.PathResolver resolver)
Creates a subconfiguration from an existing properties object and with the the indicated SubconfImpl.PathResolver.

SubconfImpl.PropertiesConfig(Map props, SubconfImpl.PathResolver resolver, Map services)
Creates a subconfiguration from an existing properties object and with the the indicated SubconfImpl.PathResolver.

SubconfImpl.PropertiesConfig(URL url)
Reads the property-file in memory and initializes the possibility to start the services but does not create them.

Method Summary

protected void	createService(String serviceInterfaceName) Constructs the service according to the indicated specifications.
Collection	getChildrenNames(String prefix) Returns the next step completion given the named prefix.
URL	getPath(String name) Returns a file constructed relative to the path of the url provided in the sole constructor.
String	getProperty(String name) Returns the values for the given name or null if there's none.
Iterator	getPropertyNames() Returns an enumeration of all the property names.
Object	getService(String serviceInterfaceName) This is the way to provide named services to users of the subconfiguation.
URL	getURL(String keyName) Returns the URL relative to the baseURL provided at construction time provided by the property-value whose key is the given name, or null if there is no such key.
URL	pathFromString(String pathString) Computes the path for the obtained property value.
void	refreshServices() Commodity method to request the configurator to re-read the services from whichever source it was given.
void	setDefaultProperties(Map defaultProps) Expects a map with keys and values as Strings.
void	unload() Unloads the probably expensive storage of the properties.

Methods inherited from class org.activemath.abstractcontent.SubconfImpl.AbstractSubconfiguration

getBoolean, getInt, getSubconfiguration

Methods inherited from class java.lang.Object

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

Field Detail

services

protected final Map services

This map has, as keys, the interfaceName (as used in getService(java.lang.String)) and as values either the created service or a String object, the property child-name that defines the service, or this same name followed by " BEING INITTED" if it is being constructed, or a Throwable is the initialization of the service went wrong (it is attempted only once).

Constructor Detail

SubconfImpl.PropertiesConfig

public SubconfImpl.PropertiesConfig(URL url)
                             throws IOException

Reads the property-file in memory and initializes the possibility to start the services but does not create them.

Throws:

IOException

SubconfImpl.PropertiesConfig

public SubconfImpl.PropertiesConfig(Map props,
                                    SubconfImpl.PathResolver resolver)

Creates a subconfiguration from an existing properties object and with the the indicated SubconfImpl.PathResolver. Services are created using the same approach.

See Also:

SubconfImpl.Util.makeBasedPathResolver(java.net.URL)

SubconfImpl.PropertiesConfig

public SubconfImpl.PropertiesConfig(Map props,
                                    SubconfImpl.PathResolver resolver,
                                    Map services)

Creates a subconfiguration from an existing properties object and with the the indicated SubconfImpl.PathResolver. Services are created using the same approach except if they are already defined in the services parameter where they will be simply fetched (and not checked). Do note that a service (i.e. a value in the services table) is not allowed to be a String object.

See Also:

SubconfImpl.Util.makeBasedPathResolver(java.net.URL)

Method Detail

getURL

public URL getURL(String keyName)

Returns the URL relative to the baseURL provided at construction time provided by the property-value whose key is the given name, or null if there is no such key.

refreshServices

public void refreshServices()

Description copied from interface: Subconfiguration

Commodity method to request the configurator to re-read the services from whichever source it was given. Useful for services created, e.g., from system-properties after a preference update. Implementations are not required to provide this service but should not fail if they don't.

Specified by:

refreshServices in interface Subconfiguration

createService

protected void createService(String serviceInterfaceName)

Constructs the service according to the indicated specifications. Note that, a service being constructed with a Subconfiguration may request another service which may give rise to cycles. In this case, a SubconfImpl.PropertiesConfig.CyclicServiceInitException will be thrown.

getService

public Object getService(String serviceInterfaceName)

Description copied from interface: Subconfiguration

This is the way to provide named services to users of the subconfiguation. Implementations using the Subconfiguraiton interface should document the class-name of the interfaces expected to be called using this method thereby documenting the necessary services.

Note that implementations of the Subconfiguration interface should only accept, as argument of this method, the class of a java-interface.

The service returned is not supposed to be twiddled or adjusted by the user of this service as such a service will presumably be shared by several users in a normal deployment.

Examples of such services could be an implementation of the JAXP's TransformerFactory interface, or an implementation of the MBaseRef interface.

Child-subconfigurations obtained through Subconfiguration.getSubconfiguration(java.lang.String) should, so as to enforce the inversion-of-control pattern, restrict the amount of services provided to the strict needed parts.

Specified by:

getService in interface Subconfiguration

Returns:

an object of a class implementing the service-interface-class.

See Also:

SubconfImpl.PropertiesConfig

getProperty

public String getProperty(String name)

Description copied from interface: Subconfiguration

Returns the values for the given name or null if there's none.

Specified by:

getProperty in interface Subconfiguration

Specified by:

getProperty in class SubconfImpl.AbstractSubconfiguration

setDefaultProperties

public void setDefaultProperties(Map defaultProps)

Expects a map with keys and values as Strings.

Specified by:

setDefaultProperties in interface Subconfiguration

Specified by:

setDefaultProperties in class SubconfImpl.AbstractSubconfiguration

getPropertyNames

public Iterator getPropertyNames()

Description copied from interface: Subconfiguration

Returns an enumeration of all the property names.

Specified by:

getPropertyNames in interface Subconfiguration

Specified by:

getPropertyNames in class SubconfImpl.AbstractSubconfiguration

getChildrenNames

public Collection getChildrenNames(String prefix)

Description copied from interface: Subconfiguration

Returns the next step completion given the named prefix.

As an example, given

    i.a.blop.c = val1

    i.b.blip   = val2

 

This method, called with "i", would return the enumeration made of the string "a" and the string "b".

Specified by:

getChildrenNames in interface Subconfiguration

Specified by:

getChildrenNames in class SubconfImpl.AbstractSubconfiguration

Parameters:

prefix - the prefix string, without the trailing "." or null if the root property names is wished.

unload

public void unload()

Unloads the probably expensive storage of the properties. Any further call to other methods of this class will result in a NullPointerException.

getPath

public URL getPath(String name)

Returns a file constructed relative to the path of the url provided in the sole constructor. Note that, in the case of a remote-host URL (e.g. an http URL), most of the methods of this File object will make no-sense.

For this reason, it is preferable, in a setting where remote communication at configuration time may happen to call getURL(java.lang.String).

Specified by:

getPath in interface Subconfiguration

Specified by:

getPath in class SubconfImpl.AbstractSubconfiguration

See Also:

Manager.getPath(java.lang.String)

pathFromString

public URL pathFromString(String pathString)

Description copied from interface: Subconfiguration

Computes the path for the obtained property value.