Pass SessionID to MemoryStore constructor from MemoryStoreFactory (#161)

* pass SessionID to MemoryStore on construction
* Update MemoryStore.java
* fix for NPE on session lookup which causes test failures

Author: jonfreedman

quickfixj-core/src/main/java/quickfix/MemoryStore.java

@@ -43,8 +43,9 @@ public MemoryStore() throws IOException {
         reset();
     }
 
-    public MemoryStore(SessionID sessionID) {
+    public MemoryStore(SessionID sessionID) throws IOException  {
         this.sessionID = sessionID;
+        reset();
     }
 
     public void get(int startSequence, int endSequence, Collection<String> messages) throws IOException {
@@ -111,8 +112,8 @@ public void setNextTargetMsgSeqNum(int next) throws IOException {
     public void refresh() throws IOException {
         // IOException is declared to maintain strict compatibility with QF JNI
         final String text = "memory store does not support refresh!";
-        if (sessionID != null) {
-            Session session = Session.lookupSession(sessionID);
+        final Session session = sessionID != null ? Session.lookupSession(sessionID) : null;
+        if (session != null) {
             session.getLog().onErrorEvent("ERROR: " + text);
         } else {
             LoggerFactory.getLogger(MemoryStore.class).error(text);

quickfixj-core/src/main/java/quickfix/MemoryStoreFactory.java

@@ -30,7 +30,7 @@ public class MemoryStoreFactory implements MessageStoreFactory {
 
     public MessageStore create(SessionID sessionID) {
         try {
-            return new MemoryStore();
+            return new MemoryStore(sessionID);
         } catch (IOException e) {
             throw new RuntimeError(e);
         }