From 29dc40a0f7fa765d6f66e7a1bdd31083f71286de Mon Sep 17 00:00:00 2001
From: Trygve Laugstøl <trygvis@inamo.no>
Date: Sat, 22 Jun 2013 09:39:49 +0200
Subject: o Adding an ActiveMQ connection to messages can be sent as a hint to
 the consumer.

---
 .../java/io/trygvis/activemq/ActiveMqHinter.java   | 152 +++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 src/main/java/io/trygvis/activemq/ActiveMqHinter.java

(limited to 'src/main/java/io/trygvis/activemq/ActiveMqHinter.java')

diff --git a/src/main/java/io/trygvis/activemq/ActiveMqHinter.java b/src/main/java/io/trygvis/activemq/ActiveMqHinter.java
new file mode 100644
index 0000000..f2cfb6e
--- /dev/null
+++ b/src/main/java/io/trygvis/activemq/ActiveMqHinter.java
@@ -0,0 +1,152 @@
+package io.trygvis.activemq;
+
+import io.trygvis.async.QueueController;
+import org.apache.activemq.ActiveMQConnectionFactory;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.jms.BytesMessage;
+import javax.jms.JMSException;
+import javax.jms.Message;
+import javax.jms.MessageConsumer;
+import javax.jms.MessageListener;
+import javax.jms.Queue;
+import javax.jms.QueueConnection;
+import javax.jms.QueueSession;
+import javax.jms.TextMessage;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.io.StringReader;
+import java.nio.charset.Charset;
+import java.sql.SQLException;
+
+import static java.lang.Long.parseLong;
+import static java.lang.System.arraycopy;
+import static java.nio.charset.Charset.forName;
+import static javax.jms.Session.AUTO_ACKNOWLEDGE;
+
+public class ActiveMqHinter implements AutoCloseable {
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private final QueueConnection c;
+
+    private static final Charset utf8 = forName("utf-8");
+
+    public ActiveMqHinter(ActiveMQConnectionFactory connectionFactory) throws JMSException {
+        log.info("Connecting to ActiveMQ Broker at {}", connectionFactory.getBrokerURL());
+        c = connectionFactory.createQueueConnection();
+        c.start();
+        log.info("Connected, clientId = {}", c.getClientID());
+    }
+
+    public void createHinter(final QueueController controller) throws JMSException {
+        QueueSession session = c.createQueueSession(false, AUTO_ACKNOWLEDGE);
+        Queue queue = session.createQueue(controller.queue.queue.name);
+        final MessageConsumer consumer = session.createConsumer(queue);
+
+        consumer.setMessageListener(new MessageListener() {
+            @Override
+            public void onMessage(Message message) {
+                if ((message instanceof TextMessage)) {
+                    String body;
+                    try {
+                        TextMessage textMessage = (TextMessage) message;
+                        body = textMessage.getText();
+                    } catch (JMSException e) {
+                        log.warn("Exception while reading body.", e);
+                        throw new RuntimeException("Exception while reading body.", e);
+                    }
+
+                    consumeString(new StringReader(body), controller);
+                } else if (message instanceof BytesMessage) {
+                    final BytesMessage bytesMessage = (BytesMessage) message;
+                    consumeString(new InputStreamReader(new ByteMessageInputStream(bytesMessage), utf8), controller);
+                } else {
+                    throw new RuntimeException("Unsupported message type: " + message.getClass());
+                }
+            }
+        });
+
+        controller.addOnStopListener(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    consumer.close();
+                } catch (JMSException e) {
+                    log.error("Error while closing JMS consumer", e);
+                }
+            }
+        });
+    }
+
+    private void consumeString(Reader reader, QueueController controller) {
+        try {
+            BufferedReader r = new BufferedReader(reader);
+
+            String line = r.readLine();
+
+            while (line != null) {
+                for (String id : line.split(",")) {
+                    controller.hint(parseLong(id.trim()));
+                }
+                line = r.readLine();
+            }
+        } catch (IOException | SQLException e) {
+            log.warn("Could not consume body.", e);
+            throw new RuntimeException("Could not consume body.", e);
+        } catch (NumberFormatException e) {
+            log.warn("Could not consume body.", e);
+            throw e;
+        }
+    }
+
+    public void close() throws JMSException {
+        c.close();
+    }
+
+    private static class ByteMessageInputStream extends InputStream {
+        private final BytesMessage bytesMessage;
+
+        public ByteMessageInputStream(BytesMessage bytesMessage) {
+            this.bytesMessage = bytesMessage;
+        }
+
+        @Override
+        public int read(byte[] b) throws IOException {
+            try {
+                return bytesMessage.readBytes(b);
+            } catch (JMSException e) {
+                throw new IOException(e);
+            }
+        }
+
+        @Override
+        public int read(byte[] out, int off, int len) throws IOException {
+            byte[] b = new byte[len];
+            try {
+                int read = bytesMessage.readBytes(b);
+                if (read == -1) {
+                    return -1;
+                }
+                arraycopy(b, 0, out, off, read);
+                return read;
+            } catch (JMSException e) {
+                throw new IOException(e);
+            }
+        }
+
+        @Override
+        public int read() throws IOException {
+            try {
+                return bytesMessage.readByte();
+            } catch (javax.jms.MessageEOFException e) {
+                return -1;
+            } catch (JMSException e) {
+                throw new IOException(e);
+            }
+        }
+    }
+}
-- 
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