Add UUID in value strategy

src/main/java/com/mongodb/kafka/connect/sink/processor/id/strategy/UuidInValueStrategy.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2008-present MongoDB, Inc.
+ *
+ * Licensed 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.
+ *
+ * Original Work: Apache License, Version 2.0, Copyright 2017 Hans-Peter Grahsl.
+ */
+package com.mongodb.kafka.connect.sink.processor.id.strategy;
+
+import static com.mongodb.kafka.connect.sink.MongoSinkTopicConfig.ID_FIELD;
+
+import java.util.Optional;
+import java.util.UUID;
+
+import org.apache.kafka.connect.errors.DataException;
+import org.apache.kafka.connect.sink.SinkRecord;
+
+import org.bson.BsonBinary;
+import org.bson.BsonDocument;
+import org.bson.BsonNull;
+import org.bson.BsonValue;
+import org.bson.UuidRepresentation;
+
+import com.mongodb.kafka.connect.sink.converter.SinkDocument;
+
+public class UuidInValueStrategy implements IdStrategy {
+
+    private static final int UUID_LENGTH = 36;
+    private static final int UUID_LENGTH_NO_DASHES = 32;
+
+    @Override
+    public BsonValue generateId(final SinkDocument doc, final SinkRecord orig) {
+        Optional<BsonDocument> optionalDoc = doc.getValueDoc();
+        BsonValue id = optionalDoc.map(d -> d.get(ID_FIELD))
+                .orElseThrow(() -> new DataException("Error: provided id strategy is used but the document structure either contained"
+                        + " no _id field or it was null"));
+
+        if (id instanceof BsonNull) {
+            throw new DataException("Error: provided id strategy used but the document structure contained an _id of type BsonNull");
+        }
+
+        return new BsonBinary(constructUuidObjectFromString(id.asString().getValue()), UuidRepresentation.STANDARD);
+    }
+
+    private UUID constructUuidObjectFromString(String uuid) {
+        if (uuid.length() == UUID_LENGTH) {
+            return UUID.fromString(uuid);
+        } else if (uuid.length() == UUID_LENGTH_NO_DASHES) {
+            return UUID.fromString(uuid.replaceFirst(
+                    "(\\p{XDigit}{8})(\\p{XDigit}{4})(\\p{XDigit}{4})(\\p{XDigit}{4})(\\p{XDigit}+)",
+                    "$1-$2-$3-$4-$5"
+            ));
+        }
+
+        throw new DataException("UUID cannot be constructed from provided string.");
+    }
+}

src/test/java/com/mongodb/kafka/connect/sink/processor/id/strategy/IdStrategyTest.java

@@ -32,6 +32,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.UUID;
 
 import org.apache.kafka.connect.errors.DataException;
 import org.apache.kafka.connect.sink.SinkRecord;
@@ -42,12 +43,14 @@
 import org.junit.platform.runner.JUnitPlatform;
 import org.junit.runner.RunWith;
 
+import org.bson.BsonBinary;
 import org.bson.BsonDocument;
 import org.bson.BsonInt32;
 import org.bson.BsonNull;
 import org.bson.BsonObjectId;
 import org.bson.BsonString;
 import org.bson.BsonValue;
+import org.bson.UuidRepresentation;
 
 import com.mongodb.kafka.connect.sink.MongoSinkTopicConfig;
 import com.mongodb.kafka.connect.sink.converter.SinkDocument;
@@ -155,6 +158,31 @@ List<DynamicTest> testIdGenerationStrategies() {
             );
             assertEquals(new BsonDocument(), idS6.generateId(sdWithoutKeyDoc, null));
         }));
+
+        IdStrategy idS7 = new UuidInValueStrategy();
+        idTests.add(dynamicTest(UuidInValueStrategy.class.getSimpleName() + " in value", () -> {
+            String idValue = "6d01622d-b3d5-466d-ae48-e414901af8f2";
+            UUID idUuid = UUID.fromString(idValue);
+            SinkDocument sdWithIdInValueDoc = new SinkDocument(null, new BsonDocument("_id", new BsonString(idValue)));
+            SinkDocument sdWithoutIdInValueDoc = new SinkDocument(null, new BsonDocument());
+            SinkDocument sdWithBsonNullIdInValueDoc = new SinkDocument(null, new BsonDocument());
+            SinkDocument sdWithInvalidUuidInValueDoc = new SinkDocument(null, new BsonDocument("_id", new BsonString("invalid")));
+            BsonValue id = idS7.generateId(sdWithIdInValueDoc, null);
+
+            assertAll("id checks",
+                    () -> assertTrue(id instanceof BsonBinary),
+                    () -> {
+                        BsonBinary bin = (BsonBinary) id;
+                        UUID foundUuid = bin.asUuid(UuidRepresentation.STANDARD);
+                        assertEquals(idUuid, foundUuid);
+                        assertEquals(idValue, foundUuid.toString());
+                    }
+            );
+            assertThrows(DataException.class, () -> idS7.generateId(sdWithoutIdInValueDoc, null));
+            assertThrows(DataException.class, () -> idS7.generateId(sdWithBsonNullIdInValueDoc, null));
+            assertThrows(DataException.class, () -> idS7.generateId(sdWithInvalidUuidInValueDoc, null));
+        }));
+
         return idTests;
     }