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ActiveMQ example source code file (MemoryMessageStore.java)

This example ActiveMQ source code file (MemoryMessageStore.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - ActiveMQ tags/keywords

exception, io, ioexception, ioexception, iterator, linkedhashmap, map, memorymessagestore, memorymessagestore, message, message, messageack, object, object, override, util

The ActiveMQ MemoryMessageStore.java source code

/**
 * 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.activemq.store.memory;

import java.io.IOException;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.activemq.broker.ConnectionContext;
import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.Message;
import org.apache.activemq.command.MessageAck;
import org.apache.activemq.command.MessageId;
import org.apache.activemq.store.MessageRecoveryListener;
import org.apache.activemq.store.MessageStore;
import org.apache.activemq.store.AbstractMessageStore;
import org.apache.activemq.usage.MemoryUsage;
import org.apache.activemq.usage.SystemUsage;

/**
 * An implementation of {@link org.apache.activemq.store.MessageStore} which
 * uses a
 * 
 * 
 */
public class MemoryMessageStore extends AbstractMessageStore {

    protected final Map<MessageId, Message> messageTable;
    protected MessageId lastBatchId;

    public MemoryMessageStore(ActiveMQDestination destination) {
        this(destination, new LinkedHashMap<MessageId, Message>());
    }

    public MemoryMessageStore(ActiveMQDestination destination, Map<MessageId, Message> messageTable) {
        super(destination);
        this.messageTable = Collections.synchronizedMap(messageTable);
    }

    public synchronized void addMessage(ConnectionContext context, Message message) throws IOException {
        synchronized (messageTable) {
            messageTable.put(message.getMessageId(), message);
        }
        message.incrementReferenceCount();
    }

    // public void addMessageReference(ConnectionContext context,MessageId
    // messageId,long expirationTime,String messageRef)
    // throws IOException{
    // synchronized(messageTable){
    // messageTable.put(messageId,messageRef);
    // }
    // }

    public Message getMessage(MessageId identity) throws IOException {
        return messageTable.get(identity);
    }

    // public String getMessageReference(MessageId identity) throws IOException{
    // return (String)messageTable.get(identity);
    // }

    public void removeMessage(ConnectionContext context, MessageAck ack) throws IOException {
        removeMessage(ack.getLastMessageId());
    }

    public void removeMessage(MessageId msgId) throws IOException {
        synchronized (messageTable) {
            Message removed = messageTable.remove(msgId);
            if( removed !=null ) {
                removed.decrementReferenceCount();
            }
            if ((lastBatchId != null && lastBatchId.equals(msgId)) || messageTable.isEmpty()) {
                lastBatchId = null;
            }
        }
    }

    public void recover(MessageRecoveryListener listener) throws Exception {
        // the message table is a synchronizedMap - so just have to synchronize
        // here
        synchronized (messageTable) {
            for (Iterator<Message> iter = messageTable.values().iterator(); iter.hasNext();) {
                Object msg = iter.next();
                if (msg.getClass() == MessageId.class) {
                    listener.recoverMessageReference((MessageId)msg);
                } else {
                    listener.recoverMessage((Message)msg);
                }
            }
        }
    }

    public void removeAllMessages(ConnectionContext context) throws IOException {
        synchronized (messageTable) {
            messageTable.clear();
        }
    }

    public void delete() {
        synchronized (messageTable) {
            messageTable.clear();
        }
    }

    
    public int getMessageCount() {
        return messageTable.size();
    }

    public void recoverNextMessages(int maxReturned, MessageRecoveryListener listener) throws Exception {
        synchronized (messageTable) {
            boolean pastLackBatch = lastBatchId == null;
            int count = 0;
            for (Iterator iter = messageTable.entrySet().iterator(); iter.hasNext();) {
                Map.Entry entry = (Entry)iter.next();
                if (pastLackBatch) {
                    count++;
                    Object msg = entry.getValue();
                    lastBatchId = (MessageId)entry.getKey();
                    if (msg.getClass() == MessageId.class) {
                        listener.recoverMessageReference((MessageId)msg);
                    } else {
                        listener.recoverMessage((Message)msg);
                    }
                } else {
                    pastLackBatch = entry.getKey().equals(lastBatchId);
                }
            }
        }
    }

    public void resetBatching() {
        lastBatchId = null;
    }

    @Override
    public void setBatch(MessageId messageId) {
        lastBatchId = messageId;
    }
    
}

Other ActiveMQ examples (source code examples)

Here is a short list of links related to this ActiveMQ MemoryMessageStore.java source code file:

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