package ca.uhn.hl7v2.examples;
   
   import java.io.FileNotFoundException;
   import java.io.FileReader;
   import java.io.IOException;
   
   import ca.uhn.hl7v2.DefaultHapiContext;
   import ca.uhn.hl7v2.HL7Exception;
   import ca.uhn.hl7v2.HapiContext;
  import ca.uhn.hl7v2.app.Connection;
  import ca.uhn.hl7v2.llp.LLPException;
  import ca.uhn.hl7v2.model.Message;
  import ca.uhn.hl7v2.util.Hl7InputStreamMessageIterator;
  
  public class SendLotsOfMessages {
  
  	public static void main(String[] args) throws FileNotFoundException, HL7Exception, LLPException {
  		
  		/*
  		 * This example shows how to send lots of messages. Specifically it
  		 * reads from a file, but that is not the only way to do this.
  		 */
  
  		/*
  		 * First set up a reader. 
  		 *  
  		 * message_file.txt is a file containing lots of ER7 encoded messages we are going to
  		 * send out. 
  		 */
  		FileReader reader = new FileReader("message_file.txt");
  		
  		// Create an iterator to iterate over all the messages
  		Hl7InputStreamMessageIterator iter = new Hl7InputStreamMessageIterator(reader);
  		
  		// Create a HapiContext
  		HapiContext context = new DefaultHapiContext();
  		
  		Connection conn = null;
  		while (iter.hasNext()) {
  			
  			/* If we don't already have a connection, create one.
  			 * Note that unless something goes wrong, it's very common
  			 * to keep reusing the same connection until we are done
  			 * sending messages. Many systems keep a connection open
  			 * even if a long period will pass between messages being
  			 * sent. This is good practice, as it is much faster than
  			 * creating a new connection each time. 
  			 */ 
  			if (conn == null) {
  				boolean useTls = false;
  				int port = 8888;
  				conn = context.newClient("localhost", port, useTls);
  			}
  			
  			try {
  				Message next = iter.next();
  				Message response = conn.getInitiator().sendAndReceive(next);
  				System.out.println("Sent message. Response was " + response.encode());
  			} catch (IOException e) {
  				System.out.println("Didn't send out this message!");
  				e.printStackTrace();
  				
  				// Since we failed, close the connection
  				try {
  					conn.close();
  				} catch (IOException ignored) {
  				}
  				conn = null;
  				
  			}
  			
  		}
  		
  	}
  
  }