本文整理匯總了Java中org.kuali.rice.krms.framework.engine.expression.FunctionExpression類的典型用法代碼示例。如果您正苦於以下問題：Java FunctionExpression類的具體用法？Java FunctionExpression怎麽用？Java FunctionExpression使用的例子？那麽, 這裏精選的類代碼示例或許可以為您提供幫助。
FunctionExpression類屬於org.kuali.rice.krms.framework.engine.expression包，在下文中一共展示了FunctionExpression類的1個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的Java代碼示例。
示例1: translateToExpression
import org.kuali.rice.krms.framework.engine.expression.FunctionExpression; //導入依賴的package包/類
/**
* Translates the parameters on the given proposition definition to create an expression for evaluation.
* The proposition parameters are defined in a reverse-polish notation so a stack is used for
* evaluation purposes.
*
* @param propositionDefinition the proposition definition to translate
*
* @return the translated expression for the given proposition, this
* expression, when evaluated, will return a Boolean.
*/
protected Expression<Boolean> translateToExpression(PropositionDefinition propositionDefinition) {
LinkedList<Expression<? extends Object>> stack = new LinkedList<Expression<? extends Object>>();
for (PropositionParameter parameter : propositionDefinition.getParameters()) {
PropositionParameterType parameterType = PropositionParameterType.fromCode(parameter.getParameterType());
if (parameterType == PropositionParameterType.CONSTANT) {
// TODO - need some way to define data type on the prop parameter as well? Not all constants will actually be String values!!!
stack.addFirst(new ConstantExpression<String>(parameter.getValue()));
} else if (parameterType == PropositionParameterType.FUNCTION) {
String functionId = parameter.getValue();
FunctionDefinition functionDefinition = functionRepositoryService.getFunction(functionId);
if (functionDefinition == null) {
throw new RepositoryDataException("Unable to locate function with the given id: " + functionId);
}
FunctionTypeService functionTypeService = typeResolver.getFunctionTypeService(functionDefinition);
Function function = functionTypeService.loadFunction(functionDefinition);
// TODO throw an exception if function is null?
List<FunctionParameterDefinition> parameters = functionDefinition.getParameters();
if (stack.size() < parameters.size()) {
throw new RepositoryDataException("Failed to initialize custom function '" + functionDefinition.getNamespace() + " " + functionDefinition.getName() +
"'. There were only " + stack.size() + " values on the stack but function requires at least " + parameters.size());
}
List<Expression<? extends Object>> arguments = new ArrayList<Expression<? extends Object>>();
// work backward through the list to match params to the stack
for (int index = parameters.size() - 1; index >= 0; index--) {
FunctionParameterDefinition parameterDefinition = parameters.get(index);
// TODO need to check types here? expression object probably needs a getType on it so that we can confirm that the types will be compatible?
parameterDefinition.getParameterType();
Expression<? extends Object> argument = stack.removeFirst();
arguments.add(argument);
}
String[] parameterTypes = getFunctionParameterTypes(functionDefinition);
stack.addFirst(new FunctionExpression(function, parameterTypes, arguments, getComparisonOperatorService()));
} else if (parameterType == PropositionParameterType.OPERATOR) {
ComparisonOperator operator = ComparisonOperator.fromCode(parameter.getValue());
if (stack.size() < 2) {
throw new RepositoryDataException("Failed to initialize expression for comparison operator " +
operator + " because a sufficient number of arguments was not available on the stack. "
+ "Current contents of stack: " + stack.toString());
}
Expression<? extends Object> rhs = stack.removeFirst();
Expression<? extends Object> lhs = stack.removeFirst();
stack.addFirst(new BinaryOperatorExpression(operator, lhs, rhs));
} else if (parameterType == PropositionParameterType.TERM) {
String termId = parameter.getValue();
TermDefinition termDefinition = getTermRepositoryService().getTerm(termId);
if (termDefinition == null) { throw new RepositoryDataException("unable to load term with id " + termId);}
Term term = translateTermDefinition(termDefinition);
stack.addFirst(new TermExpression(term));
}
}
if (stack.size() != 1) {
throw new RepositoryDataException("Final contents of expression stack are incorrect, there should only be one entry but was " + stack.size() +". Current contents of stack: " + stack.toString());
}
return new BooleanValidatingExpression(stack.removeFirst());
}