org.globus.wsrf.topicexpression
Interface TopicExpressionEngine

All Known Implementing Classes:

TopicExpressionEngineImpl

public interface TopicExpressionEngine

The TopicExpressionEngine interface is used to map queries on a topic list to the appropriate TopicExpressionEvaluators and then return the result. TopicExpressionEvaluators can be preconfigured or dynamically added at runtime.

See Also:

TopicExpressionEvaluator

Method Summary

java.util.List	getConcretePath(TopicExpressionType topicExpression) Converts the expression from dialect specific form to a ordered list of QNames.
TopicExpressionEvaluator	getEvaluator(java.lang.String dialect) Gets the evaluator currently registered to handle a topic expression of the specified dialect.
java.lang.String[]	getSupportedDialects() Returns a list of URIs representing the registered topic expression dialects
void	registerEvaluator(TopicExpressionEvaluator evaluator) registers a new evaluator that can be used to evaluate topic expressions
java.util.Collection	resolveTopicExpression(TopicExpressionType topicExpression, TopicList topicList) Resolves a topic expression using the passed topic list.

Method Detail

registerEvaluator

public void registerEvaluator(TopicExpressionEvaluator evaluator)

registers a new evaluator that can be used to evaluate topic expressions

Parameters:

evaluator - implementation of evaluator to be used for evaluating topic expressions

resolveTopicExpression

public java.util.Collection resolveTopicExpression(TopicExpressionType topicExpression,
                                                   TopicList topicList)
                                            throws UnsupportedTopicExpressionDialectException,
                                                   TopicExpressionResolutionException,
                                                   InvalidTopicExpressionException,
                                                   TopicExpressionException

Resolves a topic expression using the passed topic list. The appropraite TopicExpressionEvaluator is used based on the dialect element.

Parameters:

topicExpression - topic expression

topicList - the topic list to apply the expression to

Returns:

the set of topics the expression evaluated to

Throws:

UnsupportedTopicExpressionDialectException - if the topic expression dialect is not supported

TopicExpressionResolutionException - if the expression could not be evaluated

InvalidTopicExpressionException - if the topic expression is invalid

TopicExpressionException - if any other error occurs

getConcretePath

public java.util.List getConcretePath(TopicExpressionType topicExpression)
                               throws UnsupportedTopicExpressionDialectException,
                                      TopicExpressionResolutionException,
                                      InvalidTopicExpressionException,
                                      TopicExpressionException

Converts the expression from dialect specific form to a ordered list of QNames. This method throws an exception if the expression does not evaluate to a concrete topic path.

Parameters:

topicExpression - topic expression

Returns:

a list of QNames describing the concrete topic path

Throws:

UnsupportedTopicExpressionDialectException - if the topic expression dialect is not supported

TopicExpressionResolutionException - if the expression could not be evaluated

InvalidTopicExpressionException - if the topic expression is invalid

TopicExpressionException - if any other error occurs

getEvaluator

public TopicExpressionEvaluator getEvaluator(java.lang.String dialect)

Gets the evaluator currently registered to handle a topic expression of the specified dialect.

Returns:

the matching topic expression evaluator or null if none was found

getSupportedDialects

public java.lang.String[] getSupportedDialects()

Returns a list of URIs representing the registered topic expression dialects

Returns:

the list of supported dialects