Github user rmetzger commented on a diff in the pull request:
https://github.com/apache/flink/pull/2314#discussion_r75083728
--- Diff:
flink-streaming-connectors/flink-connector-activemq/src/main/java/org/apache/flink/streaming/connectors/activemq/AMQSource.java
---
@@ -0,0 +1,258 @@
+/*
+ * 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.flink.streaming.connectors.activemq;
+
+import org.apache.activemq.ActiveMQConnectionFactory;
+import org.apache.activemq.ActiveMQSession;
+import org.apache.flink.api.common.functions.RuntimeContext;
+import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.java.typeutils.ResultTypeQueryable;
+import org.apache.flink.configuration.Configuration;
+import
org.apache.flink.streaming.api.functions.source.MessageAcknowledgingSourceBase;
+import org.apache.flink.streaming.api.operators.StreamingRuntimeContext;
+import org.apache.flink.streaming.util.serialization.DeserializationSchema;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.jms.BytesMessage;
+import javax.jms.Connection;
+import javax.jms.Destination;
+import javax.jms.ExceptionListener;
+import javax.jms.JMSException;
+import javax.jms.Message;
+import javax.jms.MessageConsumer;
+import javax.jms.Session;
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * Source for reading messages from an ActiveMQ queue.
+ * <p>
+ * To create an instance of AMQSink class one should initialize and
configure an
+ * instance of a connection factory that will be used to create a
connection.
+ * This source is waiting for incoming messages from ActiveMQ and converts
them from
+ * an array of bytes into an instance of the output type. If an incoming
+ * message is not a message with an array of bytes, this message is ignored
+ * and warning message is logged.
+ *
+ * @param <OUT> type of output messages
+ */
+public class AMQSource<OUT> extends MessageAcknowledgingSourceBase<OUT,
String>
+ implements ResultTypeQueryable<OUT> {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(AMQSource.class);
+
+ private final ActiveMQConnectionFactory connectionFactory;
+ private final String queueName;
+ private final DeserializationSchema<OUT> deserializationSchema;
+ private boolean logFailuresOnly = false;
+ private RunningChecker runningChecker;
+ private transient Connection connection;
+ private transient Session session;
+ private transient MessageConsumer consumer;
+ private boolean autoAck;
+ private HashMap<String, Message> unaknowledgedMessages = new
HashMap<>();
+
+ /**
+ * Create AMQSource.
+ *
+ * @param connectionFactory factory that will be used to create a
connection with ActiveMQ
+ * @param queueName name of an ActiveMQ queue to read from
+ * @param deserializationSchema schema to deserialize incoming messages
+ */
+ public AMQSource(ActiveMQConnectionFactory connectionFactory, String
queueName, DeserializationSchema<OUT> deserializationSchema) {
+ this(connectionFactory, queueName, deserializationSchema, new
RunningCheckerImpl());
+ }
+
+ /**
+ * Create AMQSource.
+ *
+ * @param connectionFactory factory that will be used to create a
connection with ActiveMQ
+ * @param queueName name of an ActiveMQ queue to read from
+ * @param deserializationSchema schema to deserialize incoming messages
+ * @param runningChecker running checker that is used to decide if the
source is still running
+ */
+ AMQSource(ActiveMQConnectionFactory connectionFactory, String
queueName, DeserializationSchema<OUT> deserializationSchema, RunningChecker
runningChecker) {
+ super(String.class);
+ this.connectionFactory = connectionFactory;
+ this.queueName = queueName;
+ this.deserializationSchema = deserializationSchema;
+ this.runningChecker = runningChecker;
+ }
+
+ /**
+ * Defines whether the producer should fail on errors, or only log them.
+ * If this is set to true, then exceptions will be only logged, if set
to false,
+ * exceptions will be eventually thrown and cause the streaming program
to
+ * fail (and enter recovery).
+ *
+ * @param logFailuresOnly The flag to indicate logging-only on
exceptions.
+ */
+ public void setLogFailuresOnly(boolean logFailuresOnly) {
+ this.logFailuresOnly = logFailuresOnly;
+ }
+
+ @Override
+ public void open(Configuration config) throws Exception {
+ super.open(config);
+ // Create a Connection
+ connection = connectionFactory.createConnection();
+ connection.start();
+
+ connection.setExceptionListener(new ExceptionListener() {
+ @Override
+ public void onException(JMSException e) {
+ LOG.error("Received ActiveMQ exception", e);
--- End diff --
I agree, there's no need to ignore (= log only) an exception in open().
However, I was referring to this asynchronous exception handler for the
connection. I assume this callback can be called every time in the life of the
source. So if the user has logFailuresOnly=false, an async exception from the
exception listener should cause a failure of whatever operation is called next
(close, invoke, ..)
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