Honor new round-robin property

If round-robin equals true, if we have defined alternate hosts/ports,
we round-robin through those hosts/ports instead of starting at the
primary port on every attempt.

The patch was suggested in jpos-users by Bhavik Kumar, we just added
an option to make it configurable, with a default to the original
behaviour (round-robin=false)

CREDITS

@@ -89,6 +89,7 @@ Bjarne Henriksen <[email protected]>
 Michał Wiercioch <[email protected]>
 Grzegorz Wieczorek <[email protected]>
 Martin Muguiro <[email protected]>
+Bhavik Kumar <[email protected]>
 
 Contributors from other OpenSource projects
 -------------------------------------------

jpos/src/main/java/org/jpos/iso/BaseChannel.java

@@ -102,6 +102,8 @@ public abstract class BaseChannel extends Observable
     protected String originalRealm = null;
     protected byte[] header = null;
     private static final int DEFAULT_TIMEOUT = 300000;
+    private int nextHostPort = 0;
+    private boolean roundRobin = false;
 
     /**
      * constructor shared by server and client
@@ -320,10 +322,13 @@ protected Socket newSocket (String[] hosts, int[] ports, LogEvent evt)
         throws IOException
     {
         Socket s = null;
+        if (!roundRobin)
+            nextHostPort = 0;
         for (int i=0; i<hosts.length; i++) {
             try {
-                evt.addMessage (hosts[i]+":"+ports[i]);
-                s = newSocket (hosts[i], ports[i]);
+                int ii = nextHostPort++ % hosts.length;
+                evt.addMessage ("Try " + i + " " + hosts[ii]+":"+ports[ii]);
+                s = newSocket (hosts[ii], ports[ii]);
                 break;
             } catch (IOException e) {
                 evt.addMessage ("  " + e.getMessage());
@@ -1006,6 +1011,7 @@ public void setConfiguration (Configuration cfg)
         setOverrideHeader(cfg.getBoolean ("override-header", false));
         keepAlive = cfg.getBoolean ("keep-alive", false);
         expectKeepAlive = cfg.getBoolean ("expect-keep-alive", false);
+        roundRobin = cfg.getBoolean ("round-robin", false);
         if (socketFactory != this && socketFactory instanceof Configurable)
             ((Configurable)socketFactory).setConfiguration (cfg);
         try {