From 31ffa5e816d59222abbf4504e77f49a407982100 Mon Sep 17 00:00:00 2001
From: Chris Cranford <chris@hibernate.org>
Date: Thu, 18 Mar 2021 22:23:41 -0400
Subject: [PATCH] DBZ-2994 Fix ClassCastException & compilation error

---
 .../oracle/OracleSnapshotChangeEventSource.java     |  2 +-
 .../debezium/connector/oracle/LogMinerHelperIT.java | 13 ++-----------
 2 files changed, 3 insertions(+), 12 deletions(-)

diff --git a/debezium-connector-oracle/src/main/java/io/debezium/connector/oracle/OracleSnapshotChangeEventSource.java b/debezium-connector-oracle/src/main/java/io/debezium/connector/oracle/OracleSnapshotChangeEventSource.java
index cf36dcdc3..c73c2c4dd 100644
--- a/debezium-connector-oracle/src/main/java/io/debezium/connector/oracle/OracleSnapshotChangeEventSource.java
+++ b/debezium-connector-oracle/src/main/java/io/debezium/connector/oracle/OracleSnapshotChangeEventSource.java
@@ -244,7 +244,7 @@ protected void readTableStructure(ChangeEventSourceContext sourceContext, Relati
 
     @Override
     protected String enhanceOverriddenSelect(RelationalSnapshotContext snapshotContext, String overriddenSelect, TableId tableId) {
-        long snapshotOffset = (Long) snapshotContext.offset.getOffset().get("scn");
+        String snapshotOffset = (String) snapshotContext.offset.getOffset().get(SourceInfo.SCN_KEY);
         String token = connectorConfig.getTokenToReplaceInSnapshotPredicate();
         if (token != null) {
             return overriddenSelect.replaceAll(token, " AS OF SCN " + snapshotOffset);
diff --git a/debezium-connector-oracle/src/test/java/io/debezium/connector/oracle/LogMinerHelperIT.java b/debezium-connector-oracle/src/test/java/io/debezium/connector/oracle/LogMinerHelperIT.java
index 39119d413..cbaadf3f7 100644
--- a/debezium-connector-oracle/src/test/java/io/debezium/connector/oracle/LogMinerHelperIT.java
+++ b/debezium-connector-oracle/src/test/java/io/debezium/connector/oracle/LogMinerHelperIT.java
@@ -14,7 +14,6 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 
@@ -114,16 +113,8 @@ public void shouldAddRightRedoFiles() throws Exception {
         assertThat(redoLogFilesCount + archivedLogFilesForMining.size()).isEqualTo(getNumberOfAddedLogFiles(conn));
     }
 
-    private Scn getOldestArchivedScn(List<Scn> oneDayArchivedNextScn) throws Exception {
-        Scn oldestArchivedScn;
-        Optional<Scn> archivedScn = oneDayArchivedNextScn.stream().min(Scn::compareTo);
-        if (archivedScn.isPresent()) {
-            oldestArchivedScn = archivedScn.get();
-        }
-        else {
-            oldestArchivedScn = Scn.ZERO;
-        }
-        return oldestArchivedScn;
+    private Scn getOldestArchivedScn(List<Scn> oneDayArchivedNextScn) {
+        return oneDayArchivedNextScn.stream().min(Scn::compareTo).orElse(Scn.NULL);
     }
 
     private static int getNumberOfAddedLogFiles(OracleConnection conn) throws SQLException {