Examples with AttributeExpressionLanguageParsingException org.apache.nifi.attribute.expression.language.exception.AttributeExpressionLanguageParsingException used on opensource projects

Example 6 with AttributeExpressionLanguageParsingException

use of org.apache.nifi.attribute.expression.language.exception.AttributeExpressionLanguageParsingException in project nifi by apache.

the class ExpressionCompiler method compile.

public CompiledExpression compile(final String expression) {
    try {
        final CharStream input = new ANTLRStringStream(expression);
        final AttributeExpressionLexer lexer = new AttributeExpressionLexer(input);
        final CommonTokenStream lexerTokenStream = new CommonTokenStream(lexer);
        final AttributeExpressionParser parser = new AttributeExpressionParser(lexerTokenStream);
        final Tree ast = (Tree) parser.query().getTree();
        final Tree tree = ast.getChild(0);
        final Evaluator<?> evaluator = buildEvaluator(tree);
        verifyMappingEvaluatorReduced(evaluator);
        final Set<Evaluator<?>> allEvaluators = new HashSet<>(evaluators);
        this.evaluators.clear();
        return new CompiledExpression(expression, evaluator, tree, allEvaluators);
    } catch (final AttributeExpressionLanguageParsingException e) {
        throw e;
    } catch (final Exception e) {
        throw new AttributeExpressionLanguageParsingException(e);
    }
}

Example 7 with AttributeExpressionLanguageParsingException

use of org.apache.nifi.attribute.expression.language.exception.AttributeExpressionLanguageParsingException in project nifi by apache.

the class ExpressionCompiler method buildExpressionEvaluator.

@SuppressWarnings({ "rawtypes", "unchecked" })
private Evaluator<?> buildExpressionEvaluator(final Tree tree) {
    if (tree.getChildCount() == 0) {
        throw new AttributeExpressionLanguageParsingException("EXPRESSION tree node has no children");
    }
    final Evaluator<?> evaluator;
    if (tree.getChildCount() == 1) {
        evaluator = buildEvaluator(tree.getChild(0));
    } else {
        // we can chain together functions in the form of:
        // ${x:trim():substring(1,2):trim()}
        // in this case, the subject of the right-most function is the function to its left; its
        // subject is the function to its left (the first trim()), and its subject is the value of
        // the 'x' attribute. We accomplish this logic by iterating over all of the children of the
        // tree from the right-most child going left-ward.
        evaluator = buildFunctionExpressionEvaluator(tree, 0);
    }
    Evaluator<?> chosenEvaluator = evaluator;
    final Evaluator<?> rootEvaluator = getRootSubjectEvaluator(evaluator);
    if (rootEvaluator != null) {
        if (rootEvaluator instanceof MultiAttributeEvaluator) {
            final MultiAttributeEvaluator multiAttrEval = (MultiAttributeEvaluator) rootEvaluator;
            switch(multiAttrEval.getEvaluationType()) {
                case ANY_ATTRIBUTE:
                case ANY_MATCHING_ATTRIBUTE:
                case ANY_DELINEATED_VALUE:
                    chosenEvaluator = new AnyAttributeEvaluator((BooleanEvaluator) evaluator, multiAttrEval);
                    break;
                case ALL_ATTRIBUTES:
                case ALL_MATCHING_ATTRIBUTES:
                case ALL_DELINEATED_VALUES:
                    {
                        final ResultType resultType = evaluator.getResultType();
                        if (resultType == ResultType.BOOLEAN) {
                            chosenEvaluator = new AllAttributesEvaluator((BooleanEvaluator) evaluator, multiAttrEval);
                        } else if (evaluator instanceof ReduceEvaluator) {
                            chosenEvaluator = new MappingEvaluator((ReduceEvaluator) evaluator, multiAttrEval);
                        } else {
                            throw new AttributeExpressionLanguageException("Cannot evaluate Expression because it attempts to reference multiple attributes but does not use a reducing function");
                        }
                        break;
                    }
            }
            evaluators.add(chosenEvaluator);
            switch(multiAttrEval.getEvaluationType()) {
                case ANY_ATTRIBUTE:
                    chosenEvaluator.setToken("anyAttribute");
                    break;
                case ANY_MATCHING_ATTRIBUTE:
                    chosenEvaluator.setToken("anyMatchingAttribute");
                    break;
                case ANY_DELINEATED_VALUE:
                    chosenEvaluator.setToken("anyDelineatedValue");
                    break;
                case ALL_ATTRIBUTES:
                    chosenEvaluator.setToken("allAttributes");
                    break;
                case ALL_MATCHING_ATTRIBUTES:
                    chosenEvaluator.setToken("allMatchingAttributes");
                    break;
                case ALL_DELINEATED_VALUES:
                    chosenEvaluator.setToken("allDelineatedValues");
                    break;
            }
        }
    }
    return chosenEvaluator;
}