uses one and only one exchange - for now

src/opensesim/trader/SimpleTrader.java

@@ -26,6 +26,7 @@
 package opensesim.trader;
 
 import opensesim.world.AbstractTrader;
+import opensesim.world.Exchange;
 import opensesim.world.World;
 import opensesim.world.scheduler.Event;
 import opensesim.world.scheduler.EventListener;
@@ -35,20 +36,21 @@ import org.json.JSONObject;
  *
  * @author 7u83 <7u83@mail.ru>
  */
-public class SimpleTrader extends AbstractTrader implements EventListener{
+public class SimpleTrader extends AbstractTrader implements EventListener {
+
+    Exchange ex = null;
 
     @Override
     public String getStrategyTypeName() {
         return "Very Simple Trader";
     }
 
-    
-    public SimpleTrader(World world, JSONObject cfg){
-        super(world,cfg);
+    public SimpleTrader(World world, JSONObject cfg) {
+        super(world, cfg);
     }
 
-    public SimpleTrader(){
-        this(null,null);
+    public SimpleTrader() {
+        this(null, null);
     }
 
     float initial_delay[] = new float[2];
@@ -69,12 +71,23 @@ public class SimpleTrader extends AbstractTrader implements EventListener{
         return 0;
     }
 
-    
     @Override
     public void start() {
         setVerbose(true);
         setStatus("Trader started");
 
+        // set exchange if we haven't one already
+        if (ex == null) {
+            ex = getWorld().getDefaultExchange();
+        }
+        if (ex != null) {
+            this.log(String.format("Exchange is %s", ex.getName()));
+        } else {
+            this.log("No exchange. Stopping.");
+            setStatus("Stopped.");
+            return;
+        }
+
         long delay = (long) (1000.0f * getWorld().randNextFloat(3.0f, 12.7f));
         setStatus(String.format("Initial delay: Sleeping for %d seconds.", delay));
         getWorld().schedule(this, delay);
@@ -90,10 +103,10 @@ public class SimpleTrader extends AbstractTrader implements EventListener{
     public long receive(Event task) {
         //   System.out.printf("Here we are !!! %f\n", getWorld().randNextFloat(12f, 27f));
 
-     long diff = getWorld().currentTimeMillis()-last_time;
+        long diff = getWorld().currentTimeMillis() - last_time;
         last_time = getWorld().currentTimeMillis();
 
-     System.out.printf("Here we are: %d - [%d]\n",Thread.currentThread().getId(),diff);
+        System.out.printf("Here we are: %d - [%d]\n", Thread.currentThread().getId(), diff);
         getWorld().schedule(this, 1000);
         return -1;
     }