Changed the scope of BULK_COPY_OPERATION_CACHE to connection.

src/main/java/com/microsoft/sqlserver/jdbc/SQLServerBulkCopy.java

@@ -5,7 +5,6 @@
 
 package com.microsoft.sqlserver.jdbc;
 
-import static com.microsoft.sqlserver.jdbc.SQLServerConnection.BULK_COPY_OPERATION_CACHE;
 import static com.microsoft.sqlserver.jdbc.Util.getHashedSecret;
 import static java.nio.charset.StandardCharsets.UTF_16LE;
 import static java.nio.charset.StandardCharsets.UTF_8;
@@ -1731,19 +1730,19 @@ private void getDestinationMetadata() throws SQLServerException {
 
         String escapedDestinationTableName = Util.escapeSingleQuotes(destinationTableName);
         String key = null;
-
+        HashMap<String, Map<Integer, SQLServerBulkCopy.BulkColumnMetaData>> bulkCopyOperationCache = connection.getBulkCopyOperationCache();
         if (connection.getcacheBulkCopyMetadata()) {
             String databaseName = connection.activeConnectionProperties
                     .getProperty(SQLServerDriverStringProperty.DATABASE_NAME.toString());
             key = getHashedSecret(new String[] {escapedDestinationTableName, databaseName});
-            destColumnMetadata = BULK_COPY_OPERATION_CACHE.get(key);
+            destColumnMetadata = bulkCopyOperationCache.get(key);
         }
 
         if (null == destColumnMetadata || destColumnMetadata.isEmpty()) {
             if (connection.getcacheBulkCopyMetadata()) {
                 DESTINATION_COL_METADATA_LOCK.lock();
                 try {
-                    destColumnMetadata = BULK_COPY_OPERATION_CACHE.get(key);
+                    destColumnMetadata = bulkCopyOperationCache.get(key);
 
                     if (null == destColumnMetadata || destColumnMetadata.isEmpty()) {
                         setDestinationColumnMetadata(escapedDestinationTableName);
@@ -1758,7 +1757,7 @@ private void getDestinationMetadata() throws SQLServerException {
                         // driver will not be aware of this and the inserted data will likely be corrupted. In such
                         // scenario, we can't detect this without making an additional metadata query, which would
                         // defeat the purpose of caching.
-                        BULK_COPY_OPERATION_CACHE.put(key, destColumnMetadata);
+                        bulkCopyOperationCache.put(key, destColumnMetadata);
                     }
                 } finally {
                     DESTINATION_COL_METADATA_LOCK.unlock();

src/main/java/com/microsoft/sqlserver/jdbc/SQLServerConnection.java

@@ -1763,7 +1763,7 @@ public static void clearUserTokenCache() {
     /** transaction descriptor */
     private byte[] transactionDescriptor = new byte[8];
 
-    static final HashMap<String, Map<Integer, SQLServerBulkCopy.BulkColumnMetaData>> BULK_COPY_OPERATION_CACHE = new HashMap<>();
+    final HashMap<String, Map<Integer, SQLServerBulkCopy.BulkColumnMetaData>> bulkCopyOperationCache = new HashMap<>();
 
     /**
      * Flag (Yukon and later) set to true whenever a transaction is rolled back..The flag's value is reset to false when
@@ -1782,6 +1782,9 @@ private void setState(State state) {
         this.state = state;
     }
 
+    final HashMap<String, Map<Integer, SQLServerBulkCopy.BulkColumnMetaData>> getBulkCopyOperationCache() {
+        return bulkCopyOperationCache;
+    }
     /**
      * This function actually represents whether a database session is not open. The session is not available before the
      * session is established and after the session is closed.
@@ -2040,6 +2043,11 @@ final void resetPooledConnection() {
         if (null != preparedStatementHandleCache) {
             preparedStatementHandleCache.clear();
         }
+
+        //clear bulk copy operation cache for this connection
+        if (null != bulkCopyOperationCache) {
+            bulkCopyOperationCache.clear();
+        }
     }
 
     /**

src/test/java/com/microsoft/sqlserver/jdbc/unit/statement/BatchExecutionTest.java

@@ -170,9 +170,9 @@ public void testSqlServerBulkCopyCachingConnectionLevel() throws Exception {
 
             if (con.getClass().getName().equals("com.microsoft.sqlserver.jdbc.SQLServerConnection43")) {
                 bulkcopyMetadataCacheField = con.getClass().getSuperclass()
-                        .getDeclaredField("BULK_COPY_OPERATION_CACHE");
+                        .getDeclaredField("bulkCopyOperationCache");
             } else {
-                bulkcopyMetadataCacheField = con.getClass().getDeclaredField("BULK_COPY_OPERATION_CACHE");
+                bulkcopyMetadataCacheField = con.getClass().getDeclaredField("bulkCopyOperationCache");
             }
 
             bulkcopyMetadataCacheField.setAccessible(true);
@@ -233,9 +233,9 @@ public void testSqlServerBulkCopyCachingConnectionLevelMultiThreaded() throws Ex
 
             if (con.getClass().getName().equals("com.microsoft.sqlserver.jdbc.SQLServerConnection43")) {
                 bulkcopyMetadataCacheField = con.getClass().getSuperclass()
-                        .getDeclaredField("BULK_COPY_OPERATION_CACHE");
+                        .getDeclaredField("bulkCopyOperationCache");
             } else {
-                bulkcopyMetadataCacheField = con.getClass().getDeclaredField("BULK_COPY_OPERATION_CACHE");
+                bulkcopyMetadataCacheField = con.getClass().getDeclaredField("bulkCopyOperationCache");
             }
 
             bulkcopyMetadataCacheField.setAccessible(true);