Exceptions and closing in finally

Author: Ann Witbrock

java/EmitLogTopic.java

@@ -6,23 +6,36 @@ public class EmitLogTopic {
 
   private static final String EXCHANGE_NAME = "topic_logs";
 
-  public static void main(String[] argv) throws Exception {
-
-    ConnectionFactory factory = new ConnectionFactory();
-    factory.setHost("localhost");
-    Connection connection = factory.newConnection();
-    Channel channel = connection.createChannel();
+  public static void main(String[] argv) {
+    Connection connection = null;
+    Channel channel = null;
+    try {
+      ConnectionFactory factory = new ConnectionFactory();
+      factory.setHost("localhost");
+  
+      connection = factory.newConnection();
+      channel = connection.createChannel();
 
-    channel.exchangeDeclare(EXCHANGE_NAME, "topic");
+      channel.exchangeDeclare(EXCHANGE_NAME, "topic");
 
-    String routingKey = getRouting(argv);
-    String message = getMessage(argv);
+      String routingKey = getRouting(argv);
+      String message = getMessage(argv);
 
-    channel.basicPublish(EXCHANGE_NAME, routingKey, null, message.getBytes());
-    System.out.println(" [x] Sent '" + routingKey + "':'" + message + "'");
+      channel.basicPublish(EXCHANGE_NAME, routingKey, null, message.getBytes());
+      System.out.println(" [x] Sent '" + routingKey + "':'" + message + "'");
 
-    channel.close();
-    connection.close();
+    }
+    catch  (Exception e) {
+      e.printStackTrace();
+    }
+    finally {
+      if (connection != null) {
+        try {
+          connection.close();
+        }
+        catch (Exception ignore) {}
+      }
+    }
   }
 
   private static String getRouting(String[] strings){

java/ReceiveLogsTopic.java

@@ -7,36 +7,51 @@ public class ReceiveLogsTopic {
 
   private static final String EXCHANGE_NAME = "topic_logs";
 
-  public static void main(String[] argv) throws Exception {
-
-    ConnectionFactory factory = new ConnectionFactory();
-    factory.setHost("localhost");
-    Connection connection = factory.newConnection();
-    Channel channel = connection.createChannel();
-
-    channel.exchangeDeclare(EXCHANGE_NAME, "topic");
-    String queueName = channel.queueDeclare().getQueue();
+  public static void main(String[] argv) {
+    Connection connection = null;
+    Channel channel = null;
+    try {
+      ConnectionFactory factory = new ConnectionFactory();
+      factory.setHost("localhost");
+  
+      connection = factory.newConnection();
+      channel = connection.createChannel();
+
+      channel.exchangeDeclare(EXCHANGE_NAME, "topic");
+      String queueName = channel.queueDeclare().getQueue();
 
-    if (argv.length < 1){
-      System.err.println("Usage: ReceiveLogsTopic [binding_key]...");
-      System.exit(1);
-    }
+      if (argv.length < 1){
+        System.err.println("Usage: ReceiveLogsTopic [binding_key]...");
+        System.exit(1);
+      }
 
-    for(String bindingKey : argv){    
-      channel.queueBind(queueName, EXCHANGE_NAME, bindingKey);
-    }
+      for(String bindingKey : argv){    
+        channel.queueBind(queueName, EXCHANGE_NAME, bindingKey);
+      }
 
-    System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
+      System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
 
-    QueueingConsumer consumer = new QueueingConsumer(channel);
-    channel.basicConsume(queueName, true, consumer);
+      QueueingConsumer consumer = new QueueingConsumer(channel);
+      channel.basicConsume(queueName, true, consumer);
 
-    while (true) {
-      QueueingConsumer.Delivery delivery = consumer.nextDelivery();
-      String message = new String(delivery.getBody());
-      String routingKey = delivery.getEnvelope().getRoutingKey();
+      while (true) {
+        QueueingConsumer.Delivery delivery = consumer.nextDelivery();
+        String message = new String(delivery.getBody());
+        String routingKey = delivery.getEnvelope().getRoutingKey();
 
-      System.out.println(" [x] Received '" + routingKey + "':'" + message + "'");   
+        System.out.println(" [x] Received '" + routingKey + "':'" + message + "'");   
+      }
+    }
+    catch  (Exception e) {
+      e.printStackTrace();
+    }
+    finally {
+      if (connection != null) {
+        try {
+          connection.close();
+        }
+        catch (Exception ignore) {}
+      }
     }
   }
 }