org.springframework.kafka.config.MultiMethodKafkaListenerEndpoint.java Source code

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Here is the source code for org.springframework.kafka.config.MultiMethodKafkaListenerEndpoint.java

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/*
 * Copyright 2016-2019 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.kafka.config;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import org.springframework.kafka.listener.adapter.DelegatingInvocableHandler;
import org.springframework.kafka.listener.adapter.HandlerAdapter;
import org.springframework.kafka.listener.adapter.MessagingMessageListenerAdapter;
import org.springframework.lang.Nullable;
import org.springframework.messaging.handler.invocation.InvocableHandlerMethod;

/**
 * The {@link MethodKafkaListenerEndpoint} extension for several POJO methods
 * based on the {@link org.springframework.kafka.annotation.KafkaHandler}.
 *
 * @param <K> the key type.
 * @param <V> the value type.
 *
 * @author Gary Russell
 *
 * @see org.springframework.kafka.annotation.KafkaHandler
 * @see DelegatingInvocableHandler
 */
public class MultiMethodKafkaListenerEndpoint<K, V> extends MethodKafkaListenerEndpoint<K, V> {

    private final List<Method> methods;

    private final Method defaultMethod;

    /**
     * Construct an instance for the provided methods and bean with no default method.
     * @param methods the methods.
     * @param bean the bean.
     */
    public MultiMethodKafkaListenerEndpoint(List<Method> methods, Object bean) {
        this(methods, null, bean);
    }

    /**
     * Construct an instance for the provided methods, default method and bean.
     * @param methods the methods.
     * @param defaultMethod the default method.
     * @param bean the bean.
     * @since 2.1.3
     */
    public MultiMethodKafkaListenerEndpoint(List<Method> methods, @Nullable Method defaultMethod, Object bean) {
        this.methods = methods;
        this.defaultMethod = defaultMethod;
        setBean(bean);
    }

    @Override
    protected HandlerAdapter configureListenerAdapter(MessagingMessageListenerAdapter<K, V> messageListener) {
        List<InvocableHandlerMethod> invocableHandlerMethods = new ArrayList<InvocableHandlerMethod>();
        InvocableHandlerMethod defaultHandler = null;
        for (Method method : this.methods) {
            InvocableHandlerMethod handler = getMessageHandlerMethodFactory()
                    .createInvocableHandlerMethod(getBean(), method);
            invocableHandlerMethods.add(handler);
            if (method.equals(this.defaultMethod)) {
                defaultHandler = handler;
            }
        }
        DelegatingInvocableHandler delegatingHandler = new DelegatingInvocableHandler(invocableHandlerMethods,
                defaultHandler, getBean(), getResolver(), getBeanExpressionContext(), getBeanFactory());
        return new HandlerAdapter(delegatingHandler);
    }

}