org.springframework.integration.aggregator.ExpressionEvaluatingCorrelationStrategy.java Source code

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Here is the source code for org.springframework.integration.aggregator.ExpressionEvaluatingCorrelationStrategy.java

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/*
 * Copyright 2002-2019 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.springframework.integration.aggregator;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.expression.Expression;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.SpelParserConfiguration;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.integration.handler.ExpressionEvaluatingMessageProcessor;
import org.springframework.messaging.Message;
import org.springframework.util.Assert;

/**
 * {@link CorrelationStrategy} implementation that evaluates an expression.
 *
 * @author Dave Syer
 * @author Oleg Zhurakousky
 * @author Artem Bilan
 */
public class ExpressionEvaluatingCorrelationStrategy implements CorrelationStrategy, BeanFactoryAware {

    private static final ExpressionParser expressionParser = new SpelExpressionParser(
            new SpelParserConfiguration(true, true));

    private final ExpressionEvaluatingMessageProcessor<Object> processor;

    public ExpressionEvaluatingCorrelationStrategy(String expressionString) {
        Assert.hasText(expressionString, "expressionString must not be empty");
        Expression expression = expressionParser.parseExpression(expressionString);
        this.processor = new ExpressionEvaluatingMessageProcessor<Object>(expression, Object.class);
    }

    public ExpressionEvaluatingCorrelationStrategy(Expression expression) {
        this.processor = new ExpressionEvaluatingMessageProcessor<Object>(expression, Object.class);
    }

    public Object getCorrelationKey(Message<?> message) {
        return this.processor.processMessage(message);
    }

    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        if (beanFactory != null) {
            this.processor.setBeanFactory(beanFactory);
        }
    }

}