QA fixes: use StringBuilder, doWork, constant queue name

Author: Ann

java/NewTask.java

@@ -1,39 +1,46 @@
+import java.io.IOException;
 import com.rabbitmq.client.ConnectionFactory;
 import com.rabbitmq.client.Connection;
 import com.rabbitmq.client.Channel;
 import com.rabbitmq.client.MessageProperties;
 
 public class NewTask {
+  
+  private static final String TASK_QUEUE_NAME = "task_queue";
+
   public static void main(String[] argv) throws java.io.IOException {
-    Connection connection = null;
+
     ConnectionFactory factory = new ConnectionFactory();
     factory.setHost("localhost");
-    connection = factory.newConnection();
+    Connection connection = factory.newConnection();
     Channel channel = connection.createChannel();
 
-    channel.queueDeclare("task_queue", true, false, false, null);
+    channel.queueDeclare(TASK_QUEUE_NAME, true, false, false, null);
 
     String message = getMessage(argv);
 
-    channel.basicPublish( "", "task_queue", 
+    channel.basicPublish( "", TASK_QUEUE_NAME, 
                 MessageProperties.PERSISTENT_TEXT_PLAIN,
                 message.getBytes());
     System.out.println(" [x] Sent '" + message + "'");
+    
     channel.close();
     connection.close();
   }
 
   private static String getMessage(String[] strings){
     if (strings.length < 1)
       return "Hello World!";
-    return joinStrings(strings);
+    return joinStrings(strings, " ");
   }  
 
-  private static String joinStrings(String[] strings){
-    String words = "";
-    for (String astring: strings)
-      words = words.concat(astring).concat(" ");
-    return words.trim();
+  private static String joinStrings(String[] strings, String delimiter) {
+    int length = strings.length;
+    if (length == 0) return "";
+    StringBuilder words = new StringBuilder(strings[0]);
+    for (int i = 1; i < length; i++) {
+      words.append(delimiter).append(strings[i]);
+    }
+    return words.toString();
   }
-}
-
+}

java/Worker.java

@@ -1,44 +1,45 @@
+import java.io.IOException;
 import com.rabbitmq.client.ConnectionFactory;
 import com.rabbitmq.client.Connection;
 import com.rabbitmq.client.Channel;
 import com.rabbitmq.client.QueueingConsumer;
 
 public class Worker {
+
+  private static final String TASK_QUEUE_NAME = "task_queue";
+
   public static void main(String[] argv)
                          throws java.io.IOException,
                                 java.lang.InterruptedException {
-    Connection connection = null;
+
     ConnectionFactory factory = new ConnectionFactory();
     factory.setHost("localhost");
-    connection = factory.newConnection();
+    Connection connection = factory.newConnection();
     Channel channel = connection.createChannel();
 
-    channel.queueDeclare("task_queue", true, false, false, null);
+    channel.queueDeclare(TASK_QUEUE_NAME, true, false, false, null);
     System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
 
     channel.basicQos(1);
 
     QueueingConsumer consumer = new QueueingConsumer(channel);
-    channel.basicConsume("task_queue", false, consumer);
+    channel.basicConsume(TASK_QUEUE_NAME, false, consumer);
 
     while (true) {
       QueueingConsumer.Delivery delivery = consumer.nextDelivery();
       String body = new String(delivery.getBody());
-      System.out.println(" [x] Received " + body);
-
-      Thread.sleep( charCount(body, '.') * 1000); 
-      System.out.println(" [x] Done" );
+      
+      System.out.println(" [x] Received '" + body + "'");
+      doWork(body);
+      System.out.println(" [x] Done");
 
       channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
-    }
+    }         
   }
 
-  private static int charCount(String body, char theChar){ 
-    int count = 0;    
-    for (int index = 0; index < body.length(); index++){
-      if (theChar == body.charAt(index)) count++;
+  private static void doWork(String task) throws InterruptedException {
+        for (char ch: task.toCharArray()) {
+        	if (ch == '.') Thread.sleep(1000);
+        }
     }
-    return count;
-  }
-}
-
+}