nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/InvalidPreparedQuery.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.nifi.attribute.expression.language;


import org.apache.nifi.attribute.expression.language.exception.AttributeExpressionLanguageException;
import org.apache.nifi.expression.AttributeValueDecorator;
import org.apache.nifi.processor.exception.ProcessException;

import java.util.Collections;
import java.util.Set;

/**
 * An implementation of PreparedQuery that throws an
 * {@link AttributeExpressionLanguageException} when attempting to evaluate the
 * query. This allows a PreparedQuery to be created, even though it can't be
 * evaluated.
 */
public class InvalidPreparedQuery implements PreparedQuery {

    private final String query;
    private final String explanation;

    public InvalidPreparedQuery(final String query, final String explanation) {
        this.query = query;
        this.explanation = explanation;
    }

    @Override
    public String evaluateExpressions(final EvaluationContext evaluationContext, final AttributeValueDecorator decorator) throws ProcessException {
        throw new AttributeExpressionLanguageException("Invalid Expression: " + query + " due to " + explanation);
    }

    @Override
    public boolean isExpressionLanguagePresent() {
        return false;
    }

    @Override
    public VariableImpact getVariableImpact() {
        return VariableImpact.NEVER_IMPACTED;
    }

    @Override
    public Set<String> getExplicitlyReferencedAttributes() {
        return Collections.emptySet();
    }
}