Java tutorial
/**************************************************************** * 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.james.backend.rabbitmq; import java.io.IOException; import java.nio.charset.StandardCharsets; import java.util.Queue; import java.util.concurrent.ConcurrentLinkedQueue; import com.rabbitmq.client.AMQP; import com.rabbitmq.client.Channel; import com.rabbitmq.client.DefaultConsumer; import com.rabbitmq.client.Envelope; public class InMemoryConsumer extends DefaultConsumer { @FunctionalInterface interface Operation { void perform(); } private final ConcurrentLinkedQueue<Integer> messages; private final Operation operation; public InMemoryConsumer(Channel channel) { this(channel, () -> { }); } public InMemoryConsumer(Channel channel, Operation operation) { super(channel); this.operation = operation; this.messages = new ConcurrentLinkedQueue<>(); } @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { operation.perform(); Integer payload = Integer.valueOf(new String(body, StandardCharsets.UTF_8)); messages.add(payload); } public Queue<Integer> getConsumedMessages() { return messages; } }