org.wso2.balana.cond

Class BaseFunctionFactory

java.lang.Object

org.wso2.balana.cond.FunctionFactory

org.wso2.balana.cond.BaseFunctionFactory

Direct Known Subclasses:

StandardFunctionFactory

public class BaseFunctionFactory
extends FunctionFactory

This is a basic implementation of FunctionFactory. It implements the insertion and retrieval methods, but it doesn't actually setup the factory with any functions. It also assumes a certain model with regard to the different kinds of functions (Target, Condition, and General). For this reason, you may want to re-use this class, or you may want to extend FunctionFactory directly, if you're writing a new factory implementation.

Note that while this class is thread-safe on all creation methods, it is not safe to add support for a new function while creating an instance of a function. This follows from the assumption that most people will initialize these factories up-front, and then start processing without ever modifying the factories. If you need these mutual operations to be thread-safe, then you should write a wrapper class that implements the right synchronization.

Since:

1.2

Author:

Seth Proctor

Constructor Summary

Constructors

Constructor and Description
BaseFunctionFactory() Default constructor.
BaseFunctionFactory(FunctionFactory superset) Constructor that sets a "superset factory".
BaseFunctionFactory(FunctionFactory superset, Set supportedFunctions, Map supportedAbstractFunctions) Constructor that defines the initial functions supported by this factory and uses a superset factory.
BaseFunctionFactory(Set supportedFunctions, Map supportedAbstractFunctions) Constructor that defines the initial functions supported by this factory but doesn't use a superset factory.

Method Summary

Modifier and Type	Method and Description
void	addAbstractFunction(FunctionProxy proxy, URI identity) Adds the abstract function proxy to the factory.
void	addFunction(Function function) Adds the function to the factory.
Function	createAbstractFunction(String identity, Node root) Tries to get an instance of the specified abstract function.
Function	createAbstractFunction(String identity, Node root, String xpathVersion) Tries to get an instance of the specified abstract function.
Function	createAbstractFunction(URI identity, Node root) Tries to get an instance of the specified abstract function.
Function	createAbstractFunction(URI identity, Node root, String xpathVersion) Tries to get an instance of the specified abstract function.
Function	createFunction(String identity) Tries to get an instance of the specified function.
Function	createFunction(URI identity) Tries to get an instance of the specified function.
Set	getSupportedFunctions() Returns the function identifiers supported by this factory.

Methods inherited from class org.wso2.balana.cond.FunctionFactory

addAbstractConditionFunction, addAbstractGeneralFunction, addAbstractTargetFunction, addConditionFunction, addGeneralFunction, addTargetFunction, getConditionInstance, getConditionInstance, getGeneralInstance, getGeneralInstance, getInstance, getInstance, getTargetInstance, getTargetInstance, registerFactory, setDefaultFactory

Methods inherited from class java.lang.Object

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

Constructor Detail

BaseFunctionFactory

public BaseFunctionFactory()

Default constructor. No superset factory is used.

BaseFunctionFactory

public BaseFunctionFactory(FunctionFactory superset)

Constructor that sets a "superset factory". This is useful since the different function factories (Target, Condition, and General) have a superset relationship (Condition functions are a superset of Target functions, etc.). Adding a function to this factory will automatically add the same function to the superset factory.

Parameters:

superset - the superset factory or null

BaseFunctionFactory

public BaseFunctionFactory(Set supportedFunctions,
                           Map supportedAbstractFunctions)

Constructor that defines the initial functions supported by this factory but doesn't use a superset factory.

Parameters:

supportedFunctions - a Set of Functions

supportedAbstractFunctions - a mapping from URI to FunctionProxy

BaseFunctionFactory

public BaseFunctionFactory(FunctionFactory superset,
                           Set supportedFunctions,
                           Map supportedAbstractFunctions)

Constructor that defines the initial functions supported by this factory and uses a superset factory. Note that the functions supplied here are not propagated up to the superset factory, so you must either make sure the superst factory is correctly initialized or use BaseFunctionFactory(FunctionFactory) and then manually add each function.

Parameters:

superset - the superset factory or null

supportedFunctions - a Set of Functions

supportedAbstractFunctions - a mapping from URI to FunctionProxy

Method Detail

addFunction

public void addFunction(Function function)
                 throws IllegalArgumentException

Adds the function to the factory. Most functions have no state, so the singleton model used here is typically desireable. The factory will not enforce the requirement that a Target or Condition matching function must be boolean.

Specified by:

addFunction in class FunctionFactory

Parameters:

function - the Function to add to the factory

Throws:

IllegalArgumentException - if the function's identifier is already used or if the function is non-boolean (when this is a Target or Condition factory)

addAbstractFunction

public void addAbstractFunction(FunctionProxy proxy,
                                URI identity)
                         throws IllegalArgumentException

Adds the abstract function proxy to the factory. This is used for those functions which have state, or change behavior (for instance the standard map function, which changes its return type based on how it is used).

Specified by:

addAbstractFunction in class FunctionFactory

Parameters:

proxy - the FunctionProxy to add to the factory

identity - the function's identifier

Throws:

IllegalArgumentException - if the function's identifier is already used

getSupportedFunctions

public Set getSupportedFunctions()

Returns the function identifiers supported by this factory.

Specified by:

getSupportedFunctions in class FunctionFactory

Returns:

a Set of Strings

createFunction

public Function createFunction(URI identity)
                        throws UnknownIdentifierException,
                               FunctionTypeException

Tries to get an instance of the specified function.

Specified by:

createFunction in class FunctionFactory

Parameters:

identity - the name of the function

Throws:

UnknownIdentifierException - if the name isn't known

FunctionTypeException - if the name is known to map to an abstract function, and should therefore be created through createAbstractFunction

createFunction

public Function createFunction(String identity)
                        throws UnknownIdentifierException,
                               FunctionTypeException

Tries to get an instance of the specified function.

Specified by:

createFunction in class FunctionFactory

Parameters:

identity - the name of the function

Throws:

UnknownIdentifierException - if the name isn't known

FunctionTypeException - if the name is known to map to an abstract function, and should therefore be created through createAbstractFunction

createAbstractFunction

public Function createAbstractFunction(URI identity,
                                       Node root)
                                throws UnknownIdentifierException,
                                       ParsingException,
                                       FunctionTypeException

Tries to get an instance of the specified abstract function.

Specified by:

createAbstractFunction in class FunctionFactory

Parameters:

identity - the name of the function

root - the DOM root containing info used to create the function

Throws:

UnknownIdentifierException - if the name isn't known

FunctionTypeException - if the name is known to map to a concrete function, and should therefore be created through createFunction

ParsingException - if the function can't be created with the given inputs

createAbstractFunction

public Function createAbstractFunction(URI identity,
                                       Node root,
                                       String xpathVersion)
                                throws UnknownIdentifierException,
                                       ParsingException,
                                       FunctionTypeException

Tries to get an instance of the specified abstract function.

Specified by:

createAbstractFunction in class FunctionFactory

Parameters:

identity - the name of the function

root - the DOM root containing info used to create the function

xpathVersion - the version specified in the contianing policy, or null if no version was specified

Throws:

UnknownIdentifierException - if the name isn't known

FunctionTypeException - if the name is known to map to a concrete function, and should therefore be created through createFunction

ParsingException - if the function can't be created with the given inputs

createAbstractFunction

public Function createAbstractFunction(String identity,
                                       Node root)
                                throws UnknownIdentifierException,
                                       ParsingException,
                                       FunctionTypeException

Tries to get an instance of the specified abstract function.

Specified by:

createAbstractFunction in class FunctionFactory

Parameters:

identity - the name of the function

root - the DOM root containing info used to create the function

Throws:

UnknownIdentifierException - if the name isn't known

FunctionTypeException - if the name is known to map to a concrete function, and should therefore be created through createFunction

ParsingException - if the function can't be created with the given inputs

createAbstractFunction

public Function createAbstractFunction(String identity,
                                       Node root,
                                       String xpathVersion)
                                throws UnknownIdentifierException,
                                       ParsingException,
                                       FunctionTypeException

Tries to get an instance of the specified abstract function.

Specified by:

createAbstractFunction in class FunctionFactory

Parameters:

identity - the name of the function

root - the DOM root containing info used to create the function

xpathVersion - the version specified in the contianing policy, or null if no version was specified

Throws:

UnknownIdentifierException - if the name isn't known

FunctionTypeException - if the name is known to map to a concrete function, and should therefore be created through createFunction

ParsingException - if the function can't be created with the given inputs