org.springframework.integration.config.annotation.FilterAnnotationPostProcessor.java Source code

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Here is the source code for org.springframework.integration.config.annotation.FilterAnnotationPostProcessor.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.config.annotation;

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.List;

import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.core.annotation.AnnotatedElementUtils;
import org.springframework.integration.annotation.Filter;
import org.springframework.integration.core.MessageSelector;
import org.springframework.integration.filter.MessageFilter;
import org.springframework.integration.filter.MethodInvokingSelector;
import org.springframework.integration.util.MessagingAnnotationUtils;
import org.springframework.messaging.MessageHandler;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

/**
 * Post-processor for Methods annotated with {@link Filter @Filter}.
 *
 * @author Mark Fisher
 * @author Gary Russell
 * @author Artem Bilan
 * @since 2.0
 */
public class FilterAnnotationPostProcessor extends AbstractMethodAnnotationPostProcessor<Filter> {

    public FilterAnnotationPostProcessor(ConfigurableListableBeanFactory beanFactory) {
        super(beanFactory);
        this.messageHandlerAttributes.addAll(
                Arrays.asList("discardChannel", "throwExceptionOnRejection", "adviceChain", "discardWithinAdvice"));
    }

    @Override
    protected MessageHandler createHandler(Object bean, Method method, List<Annotation> annotations) {
        MessageSelector selector;
        if (AnnotatedElementUtils.isAnnotated(method, Bean.class.getName())) {
            Object target = resolveTargetBeanFromMethodWithBeanAnnotation(method);
            if (target instanceof MessageSelector) {
                selector = (MessageSelector) target;
            } else if (extractTypeIfPossible(target, MessageFilter.class) != null) {
                checkMessageHandlerAttributes(resolveTargetBeanName(method), annotations);
                return (MessageHandler) target;
            } else {
                selector = new MethodInvokingSelector(target);
            }
        } else {
            Assert.isTrue(
                    boolean.class.equals(method.getReturnType()) || Boolean.class.equals(method.getReturnType()),
                    "The Filter annotation may only be applied to methods with a boolean return type.");
            selector = new MethodInvokingSelector(bean, method);
        }

        MessageFilter filter = new MessageFilter(selector);

        String discardWithinAdvice = MessagingAnnotationUtils.resolveAttribute(annotations, "discardWithinAdvice",
                String.class);
        if (StringUtils.hasText(discardWithinAdvice)) {
            filter.setDiscardWithinAdvice(resolveAttributeToBoolean(discardWithinAdvice));
        }

        String throwExceptionOnRejection = MessagingAnnotationUtils.resolveAttribute(annotations,
                "throwExceptionOnRejection", String.class);
        if (StringUtils.hasText(throwExceptionOnRejection)) {
            filter.setThrowExceptionOnRejection(resolveAttributeToBoolean(throwExceptionOnRejection));
        }

        String discardChannelName = MessagingAnnotationUtils.resolveAttribute(annotations, "discardChannel",
                String.class);
        if (StringUtils.hasText(discardChannelName)) {
            filter.setDiscardChannelName(discardChannelName);
        }

        setOutputChannelIfPresent(annotations, filter);
        return filter;
    }

}