[FLINK-35094] Apply fix for Opensearch2

flink-connector-opensearch2-e2e-tests/src/test/java/org/apache/flink/core/execution/CheckpointingMode.java

@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.core.execution;
+
+import org.apache.flink.streaming.tests.OpensearchSinkE2ECase;
+
+/**
+ * This is a copy of {@link CheckpointingMode} from flink-core module introduced in Flink 1.20. We
+ * need it here to make {@link OpensearchSinkE2ECase} compatible with earlier releases. Could be
+ * removed together with dropping support of Flink 1.19.
+ */
+public enum CheckpointingMode {
+    EXACTLY_ONCE,
+    AT_LEAST_ONCE;
+
+    private CheckpointingMode() {}
+}

flink-connector-opensearch2-e2e-tests/src/test/java/org/apache/flink/streaming/tests/OpensearchSinkE2ECase.java

@@ -85,7 +85,8 @@ public OpensearchSinkE2ECase() throws Exception {}
                                     .toUri()
                                     .toURL()));
 
-    @Override
+    /** Could be removed together with dropping support of Flink 1.19. */
+    @Deprecated
     protected void checkResultWithSemantic(
             ExternalSystemDataReader<ComparableTuple2<Integer, String>> reader,
             List<ComparableTuple2<Integer, String>> testData,
@@ -109,8 +110,46 @@ protected void checkResultWithSemantic(
                 READER_RETRY_ATTEMPTS);
     }
 
+    protected void checkResultWithSemantic(
+            ExternalSystemDataReader<ComparableTuple2<Integer, String>> reader,
+            List<ComparableTuple2<Integer, String>> testData,
+            org.apache.flink.core.execution.CheckpointingMode semantic)
+            throws Exception {
+        waitUntilCondition(
+                () -> {
+                    try {
+                        List<ComparableTuple2<Integer, String>> result =
+                                reader.poll(Duration.ofMillis(READER_TIMEOUT));
+                        assertThat(sort(result).iterator())
+                                .matchesRecordsFromSource(
+                                        Collections.singletonList(sort(testData)),
+                                        convertFromCheckpointingMode(semantic));
+                        return true;
+                    } catch (Throwable t) {
+                        LOG.warn("Polled results not as expected", t);
+                        return false;
+                    }
+                },
+                5000,
+                READER_RETRY_ATTEMPTS);
+    }
+
     private static <T extends Comparable<T>> List<T> sort(List<T> list) {
         Collections.sort(list);
         return list;
     }
+
+    /** Could be removed together with dropping support of Flink 1.19. */
+    @Deprecated
+    private static org.apache.flink.streaming.api.CheckpointingMode convertFromCheckpointingMode(
+            org.apache.flink.core.execution.CheckpointingMode semantic) {
+        switch (semantic) {
+            case EXACTLY_ONCE:
+                return org.apache.flink.streaming.api.CheckpointingMode.EXACTLY_ONCE;
+            case AT_LEAST_ONCE:
+                return org.apache.flink.streaming.api.CheckpointingMode.AT_LEAST_ONCE;
+            default:
+                throw new IllegalArgumentException("Unsupported semantic: " + semantic);
+        }
+    }
 }