Some reformatting.

src/StockExchange/BuyOrder.java

@@ -2,12 +2,10 @@ package StockExchange;
 
 public class BuyOrder extends Order implements Comparable<Order> {
 
-	
-	
+    @Override
     public int compareTo(Order o) {
 
-		if (o.limit < limit)
-		{
+        if (o.limit < limit) {
             //System.out.println("return 1");
             return -1;
         }

src/StockExchange/Exchange.java

@@ -28,7 +28,7 @@ public class Exchange extends Thread {
     }
 
     // Here we store the list of quote receivers
-    TreeSet<QuoteReceiver> qrlist = new TreeSet<QuoteReceiver>();
+    TreeSet<QuoteReceiver> qrlist = new TreeSet();
 
     public void AddQuoteReceiver(QuoteReceiver qr) {
         qrlist.add(qr);
@@ -52,7 +52,7 @@ public class Exchange extends Thread {
     long lastsize;
 
     // Order orderlist[];
-    TreeSet<BuyOrder> bid = new TreeSet<BuyOrder>();
+    TreeSet<BuyOrder> bid = new TreeSet();
     TreeSet<SellOrder> ask = new TreeSet<SellOrder>();
 
     private final Semaphore available = new Semaphore(1, true);

src/StockExchange/Order.java

@@ -1,7 +1,10 @@
 package StockExchange;
 
-
 public abstract class Order implements Comparable<Order> {
+
+    /**
+     * when
+     */
     public long timestamp = 0;
     public long size;
     public double limit;
@@ -11,7 +14,6 @@ public abstract class Order implements Comparable<Order>{
     public long id = 0;
     public Account account = null;
 
-	
     enum OrderStatus {
         open, executed, canceled
     }
@@ -19,8 +21,9 @@ public abstract class Order implements Comparable<Order>{
     OrderStatus status = OrderStatus.open;
 
     public long getAge() {
-		if (timestamp==0)
+        if (timestamp == 0) {
             return 0;
+        }
         return System.currentTimeMillis() - timestamp;
     }
 

src/sesim/SeSim.java

@@ -5,6 +5,8 @@
  */
 package sesim;
 
+import StockExchange.*;
+
 /**
  *
  * @author tube
@@ -15,6 +17,10 @@ public class SeSim {
      * @param args the command line arguments
      */
     public static void main(String[] args) {
+        Exchange se = new StockExchange.Exchange();
+        se.start();
+        
+        
         // TODO code application logic here
     }