net.timewalker.ffmq4.common.session.AbstractQueueBrowser.java Source code

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Here is the source code for net.timewalker.ffmq4.common.session.AbstractQueueBrowser.java

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/*
 * This file is part of FFMQ.
 *
 * FFMQ is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * FFMQ is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with FFMQ; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package net.timewalker.ffmq4.common.session;

import java.util.Hashtable;
import java.util.List;
import java.util.Map;
import java.util.Vector;

import javax.jms.JMSException;
import javax.jms.Queue;
import javax.jms.QueueBrowser;

import net.timewalker.ffmq4.FFMQException;
import net.timewalker.ffmq4.utils.JavaTools;
import net.timewalker.ffmq4.utils.id.IntegerID;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * <p>Base implementation for a {@link QueueBrowser}</p>
 */
public abstract class AbstractQueueBrowser implements QueueBrowser {
    private static final Log log = LogFactory.getLog(AbstractQueueBrowser.class);

    // Unique ID
    protected IntegerID id;

    // Attributes
    protected Queue queue;
    protected String messageSelector;

    // Runtime
    protected Object closeLock = new Object();
    protected boolean closed;

    // Parent session
    protected AbstractSession session;

    // Children
    private Map<String, AbstractQueueBrowserEnumeration> enumMap = new Hashtable<>();

    /**
     * Constructor
     */
    public AbstractQueueBrowser(AbstractSession session, Queue queue, String messageSelector, IntegerID browserId) {
        this.session = session;
        this.queue = queue;
        this.messageSelector = messageSelector;
        this.id = browserId;
    }

    /**
     * @return the id
     */
    public final IntegerID getId() {
        return id;
    }

    /**
      * Register an enumeration
      */
    protected final void registerEnumeration(AbstractQueueBrowserEnumeration queueBrowserEnum) {
        enumMap.put(queueBrowserEnum.getId(), queueBrowserEnum);
    }

    /**
     * Unregister an enumeration
     */
    protected final void unregisterEnumeration(AbstractQueueBrowserEnumeration queueBrowserEnum) {
        enumMap.put(queueBrowserEnum.getId(), queueBrowserEnum);
    }

    /**
     * Lookup a registered enumeration
     */
    public final AbstractQueueBrowserEnumeration lookupRegisteredEnumeration(String enumId) {
        return enumMap.get(enumId);
    }

    /**
     * Close remaining browser enumerations
     */
    private void closeRemainingEnumerations() {
        List<AbstractQueueBrowserEnumeration> enumsToClose = new Vector<>();
        synchronized (enumMap) {
            enumsToClose.addAll(enumMap.values());
            for (int n = 0; n < enumsToClose.size(); n++) {
                AbstractQueueBrowserEnumeration queueBrowserEnum = enumsToClose.get(n);
                log.debug("Auto-closing unclosed queue browser enumeration : " + queueBrowserEnum);
                try {
                    queueBrowserEnum.close();
                } catch (Exception e) {
                    log.error("Could not close queue browser enumeration " + queueBrowserEnum, e);
                }
            }
        }
    }

    /*
     * (non-Javadoc)
     * @see javax.jms.QueueBrowser#getMessageSelector()
     */
    @Override
    public final String getMessageSelector() throws JMSException {
        return messageSelector;
    }

    /*
     * (non-Javadoc)
     * @see javax.jms.QueueBrowser#getQueue()
     */
    @Override
    public final Queue getQueue() throws JMSException {
        return queue;
    }

    /*
     * (non-Javadoc)
     * @see javax.jms.QueueBrowser#close()
     */
    @Override
    public final void close() throws JMSException {
        synchronized (closeLock) {
            if (closed)
                return;
            this.closed = true;
            onQueueBrowserClose();
        }
    }

    protected void onQueueBrowserClose() {
        session.unregisterBrowser(this);
        closeRemainingEnumerations();
    }

    /**
     * Check that the queue browser
     * @throws JMSException
     */
    public final void checkNotClosed() throws JMSException {
        if (closed)
            throw new FFMQException("Queue browser is closed", "QUEUE_BROWSER_CLOSED");
    }

    /* (non-Javadoc)
      * @see java.lang.Object#toString()
      */
    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();

        sb.append(JavaTools.getShortClassName(getClass()));
        sb.append("[#");
        sb.append(id);
        sb.append("] queue=");
        sb.append(queue);
        sb.append("] messageSelector=");
        sb.append(messageSelector);

        return sb.toString();
    }
}