org.apache.flink.streaming.connectors.jms.JmsQueueSource.java Source code

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Here is the source code for org.apache.flink.streaming.connectors.jms.JmsQueueSource.java

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/*
 * Copyright 2016 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
 *
 *       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.flink.streaming.connectors.jms;

import javax.annotation.Nullable;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueReceiver;
import javax.jms.QueueSession;
import javax.jms.Session;
import org.apache.flink.api.common.functions.StoppableFunction;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.functions.source.RichParallelSourceFunction;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.jms.UncategorizedJmsException;
import org.springframework.jms.support.JmsUtils;
import org.springframework.util.Assert;

public abstract class JmsQueueSource<T> extends RichParallelSourceFunction<T>
        implements StoppableFunction, InitializingBean {
    private static final long serialVersionUID = 42L;

    private static Logger logger = LoggerFactory.getLogger(JmsQueueSource.class);

    private volatile boolean isRunning = true;

    private Queue destination;
    private QueueConnectionFactory connectionFactory;
    private String messageSelector;

    private QueueConnection connection;

    // --------------------------------------------------------------------------

    public JmsQueueSource() {

    }

    public JmsQueueSource(final QueueConnectionFactory connectionFactory, final Queue destination) {
        this(connectionFactory, destination, null);
    }

    public JmsQueueSource(final QueueConnectionFactory connectionFactory, final Queue destination,
            @Nullable final String messageSelector) {
        Assert.notNull(connectionFactory, "QueueConnectionFactory must not be null");
        Assert.notNull(destination, "Queue must not be null");
        this.connectionFactory = connectionFactory;
        this.destination = destination;
        this.messageSelector = messageSelector;
    }

    @Override
    public void open(final Configuration parameters) throws Exception {
        super.open(parameters);
        final String username = parameters.getString("jms_username", null);
        final String password = parameters.getString("jms_password", null);
        connection = connectionFactory.createQueueConnection(username, password);
        final String clientId = parameters.getString("jms_client_id", null);
        if (clientId != null)
            connection.setClientID(clientId);
    }

    @Override
    public void run(final SourceContext<T> context) throws Exception {
        QueueSession session = null;
        QueueReceiver consumer = null;

        try {
            session = connection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
            consumer = session.createReceiver(destination, messageSelector);

            connection.start();

            while (isRunning) {
                context.collect(convert(consumer.receive()));
            }
        } catch (JMSException e) {
            logger.error("Error receiving message from [{}]: {}", destination.getQueueName(),
                    e.getLocalizedMessage());
            throw new UncategorizedJmsException(e);
        } finally {
            JmsUtils.closeMessageConsumer(consumer);
            JmsUtils.closeSession(session);
        }
    }

    protected abstract T convert(final Message message) throws Exception;

    @Override
    public void cancel() {
        isRunning = false;
    }

    @Override
    public void stop() {
        isRunning = false;
    }

    @Override
    public void close() throws Exception {
        super.close();
        JmsUtils.closeConnection(connection, true);
    }

    public void setDestination(final Queue destination) {
        this.destination = destination;
    }

    public void setConnectionFactory(final QueueConnectionFactory connectionFactory) {
        this.connectionFactory = connectionFactory;
    }

    public void setMessageSelector(final String messageSelector) {
        this.messageSelector = messageSelector;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        Assert.notNull(destination, "Destination queue must not be null");
        Assert.notNull(connectionFactory, "QueueConnectionFactory must not be null");
    }
}