fixed simpleDb again

server/SimpleDB.java

@@ -14,6 +14,7 @@
 import util.Configuration;
 
 import com.amazonaws.auth.BasicAWSCredentials;
+import com.amazonaws.services.dynamodb.model.ConditionalCheckFailedException;
 import com.amazonaws.services.simpledb.AmazonSimpleDBClient;
 import com.amazonaws.services.simpledb.model.CreateDomainRequest;
 import com.amazonaws.services.simpledb.model.DeleteDomainRequest;
@@ -51,23 +52,24 @@ public synchronized void createDomain(String domain){
  sdbc.createDomain(new CreateDomainRequest(domain));
 
  ArrayList<ReplaceableAttribute> newAttributes = new ArrayList<ReplaceableAttribute>();
- newAttributes.add(new ReplaceableAttribute(AttrName, " ", false));
+ newAttributes.add(new ReplaceableAttribute(AttrName, " ", true));
  PutAttributesRequest newRequest = new PutAttributesRequest();
 
-// UpdateCondition expected = new UpdateCondition();
-// expected.setName(AttrName);
-// expected.setExists(false);
+ UpdateCondition expected = new UpdateCondition();
+ expected.setName(AttrName);
+ expected.setExists(false);
 
  newRequest.setDomainName(MEMBER_LIST_DOMAIN);
  newRequest.setItemName(AttrName);
 
- //newRequest.setExpected(expected);
+ newRequest.setExpected(expected);
  newRequest.setAttributes(newAttributes);
 
  try {
  sdbc.putAttributes(newRequest);
- } catch(Exception e){
- e.printStackTrace();
+ } catch(ConditionalCheckFailedException e){
+ //e.printStackTrace();
+ System.out.println("Conditional Check failed, the attribute probably already exists.");
  }
  }
 
@@ -223,7 +225,7 @@ public void run() {
  double probOfRefresh = 1.0/localMbrList.size();
  double rand = generator.nextDouble();
 
- if(rand <= probOfRefresh)
+ //if(rand <= probOfRefresh)
  memberRefresh();
  } catch (InterruptedException e) {
  e.printStackTrace();