Simplify RollbackManager

Simplify RollbackManager using FunctionalJava
and Java 8 features.

Change-Id: Icfaa16926b90cb3cfd293c14026731671e007629
Signed-off-by: Gary Wu <gary.i.wu@huawei.com>

1 files changed, 20 insertions, 40 deletions

diff --git a/catalog-be/src/main/java/org/openecomp/sdc/common/transaction/mngr/RollbackManager.java b/catalog-be/src/main/java/org/openecomp/sdc/common/transaction/mngr/RollbackManager.java
index 0641524038..99e0da0116 100644
--- a/catalog-be/src/main/java/org/openecomp/sdc/common/transaction/mngr/RollbackManager.java
+++ b/catalog-be/src/main/java/org/openecomp/sdc/common/transaction/mngr/RollbackManager.java
@@ -20,68 +20,54 @@
 
 package org.openecomp.sdc.common.transaction.mngr;
 
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-
 import org.openecomp.sdc.common.transaction.api.RollbackHandler;
 import org.openecomp.sdc.common.transaction.api.TransactionUtils.DBActionCodeEnum;
 import org.openecomp.sdc.common.transaction.api.TransactionUtils.DBTypeEnum;
 import org.openecomp.sdc.common.util.MethodActivationStatusEnum;
 
+import fj.P;
 import fj.data.Either;
+import fj.data.HashMap;
+import fj.data.List;
 
 public class RollbackManager {
-	private Map<DBTypeEnum, RollbackHandler> rollBackHandlersMap;
-	private Integer transactionId;
-	private String userId, actionType;
+	private final HashMap<DBTypeEnum, RollbackHandler> rollbackHandlersMap;
+	private final Integer transactionId;
+	private final String userId;
+	private final String actionType;
 
-	RollbackManager(Integer transactionId, String userId, String actionType, List<RollbackHandler> roleBackHandlers) {
+	RollbackManager(Integer transactionId, String userId, String actionType, Iterable<RollbackHandler> rollbackHandlers) {
 		this.transactionId = transactionId;
 		this.userId = userId;
 		this.actionType = actionType;
-		rollBackHandlersMap = new HashMap<>();
-		for (RollbackHandler handler : roleBackHandlers) {
-			rollBackHandlersMap.put(handler.getDBType(), handler);
-		}
-
+		this.rollbackHandlersMap = HashMap.from(List.iterableList(rollbackHandlers).map(i -> P.p(i.getDBType(), i)));
 	}
 
 	public DBActionCodeEnum transactionRollback() {
-		DBActionCodeEnum rollbackResult = DBActionCodeEnum.SUCCESS;
-		Iterator<RollbackHandler> handlersItr = rollBackHandlersMap.values().iterator();
-		while (handlersItr.hasNext()) {
-			RollbackHandler handler = handlersItr.next();
-			DBActionCodeEnum rollbackCode = handler.doRollback();
-			if (rollbackCode == DBActionCodeEnum.FAIL_GENERAL) {
-				rollbackResult = DBActionCodeEnum.FAIL_GENERAL;
-			}
-		}
-
-		return rollbackResult;
+		List<DBActionCodeEnum> results = rollbackHandlersMap.values().map(RollbackHandler::doRollback);
+		boolean failure = results.exists(r -> r == DBActionCodeEnum.FAIL_GENERAL);
+		return failure ? DBActionCodeEnum.FAIL_GENERAL : DBActionCodeEnum.SUCCESS;
 	}
 
 	protected Either<RollbackHandler, MethodActivationStatusEnum> addRollbackHandler(RollbackHandler rollbackHandler) {
 		Either<RollbackHandler, MethodActivationStatusEnum> result;
-		if (rollBackHandlersMap.containsKey(rollbackHandler.getDBType())) {
+		if (rollbackHandlersMap.contains(rollbackHandler.getDBType())) {
 			result = Either.right(MethodActivationStatusEnum.NOT_ALLOWED);
 		} else {
-			rollBackHandlersMap.put(rollbackHandler.getDBType(), rollbackHandler);
+			rollbackHandlersMap.set(rollbackHandler.getDBType(), rollbackHandler);
 			result = Either.left(rollbackHandler);
 		}
 		return result;
 
 	}
 
-	protected Either<RollbackHandler, MethodActivationStatusEnum> createRollbackHandler(DBTypeEnum dbType) {
+	protected Either<RollbackHandler, MethodActivationStatusEnum> createRollbackHandler(final DBTypeEnum dbType) {
 
-		final DBTypeEnum dbTypeFinal = dbType;
 		RollbackHandler rollbackHandler = new RollbackHandler(transactionId, userId, actionType) {
 
 			@Override
 			public DBTypeEnum getDBType() {
-				return dbTypeFinal;
+				return dbType;
 			}
 
 			@Override
@@ -89,19 +75,13 @@ public class RollbackManager {
 				return true;
 			}
 		};
-		Either<RollbackHandler, MethodActivationStatusEnum> result = addRollbackHandler(rollbackHandler);
-
-		return result;
+		return addRollbackHandler(rollbackHandler);
 	}
 
 	protected Either<RollbackHandler, MethodActivationStatusEnum> getRollbackHandler(DBTypeEnum dbType) {
-		Either<RollbackHandler, MethodActivationStatusEnum> result;
-		if (rollBackHandlersMap.containsKey(dbType)) {
-			result = Either.left(rollBackHandlersMap.get(dbType));
-		} else {
-			result = Either.right(MethodActivationStatusEnum.NOT_FOUND);
-		}
-		return result;
+		// need to swap here because the uses of Either in SDC appears to be opposite of convention
+		// by convention left is failure; in SDC right is failure
+		return rollbackHandlersMap.get(dbType).toEither(MethodActivationStatusEnum.NOT_FOUND).swap();
 	}
 
 }