refs #1110 Do not try to close statetment if it is already closed as suggested by Kazuki.

Author: harawata

src/main/java/org/apache/ibatis/executor/BaseExecutor.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2009-2016 the original author or authors.
+ *    Copyright 2009-2017 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -282,7 +282,9 @@ protected abstract <E> Cursor<E> doQueryCursor(MappedStatement ms, Object parame
   protected void closeStatement(Statement statement) {
     if (statement != null) {
       try {
-        statement.close();
+        if (!statement.isClosed()) {
+          statement.close();
+        }
       } catch (SQLException e) {
         // ignore
       }

src/main/java/org/apache/ibatis/executor/BatchExecutor.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2009-2016 the original author or authors.
+ *    Copyright 2009-2017 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -131,6 +131,7 @@ public List<BatchResult> doFlushStatements(boolean isRollback) throws SQLExcepti
               keyGenerator.processAfter(this, ms, stmt, parameter);
             }
           }
+          // Close statement to close cursor #1109
           closeStatement(stmt);
         } catch (BatchUpdateException e) {
           StringBuilder message = new StringBuilder();