TIKA-4859: Accept enum values in JSON config case-insensitively

CHANGES.txt

@@ -1,5 +1,9 @@
 Release 4.1.0 - unreleased
 
+   * Enum values in JSON configuration are matched case-insensitively, so
+     "no_ocr" works as well as "NO_OCR"; the server docs used the lower-case
+     form in their examples (TIKA-4859).
+
    * The preview image of iWork '09 packages (QuickLook/Thumbnail.jpg) and of
      iWork '18 packages (preview.jpg) is emitted as a THUMBNAIL embedded
      document, as it already was for iWork '13 (TIKA-4854).

docs/modules/ROOT/pages/migration-to-4x/migrating-tika-server-4x.adoc

@@ -67,7 +67,7 @@ POST endpoints accept multipart requests with a `file` part and optional `config
 # Parse with custom PDF parser settings (requires allowPerRequestConfig)
 curl -X POST http://localhost:9998/tika/config/json \
   -F "file=@document.pdf" \
-  -F "config={\"pdf-parser\":{\"ocr\":{\"strategy\":\"no_ocr\"}}};type=application/json"
+  -F "config={\"pdf-parser\":{\"ocr\":{\"strategy\":\"NO_OCR\"}}};type=application/json"
 ----
 
 == Breaking Changes

docs/modules/ROOT/pages/using-tika/server/index.adoc

@@ -246,7 +246,7 @@ POST with multipart for custom per-request configuration:
 ----
 curl -X POST http://localhost:9998/tika/config/json \
   -F "file=@document.pdf" \
-  -F "config={\"pdf-parser\":{\"ocr\":{\"strategy\":\"no_ocr\"}}};type=application/json"
+  -F "config={\"pdf-parser\":{\"ocr\":{\"strategy\":\"NO_OCR\"}}};type=application/json"
 ----
 
 Valid handler paths under `/tika/`: `text`, `html`, `xml`, `md`, `json` (bare `/tika` returns

tika-serialization/src/main/java/org/apache/tika/config/loader/TikaObjectMapperFactory.java

@@ -19,6 +19,7 @@
 import com.fasterxml.jackson.core.JsonFactory;
 import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.MapperFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import org.slf4j.Logger;
@@ -126,6 +127,10 @@ public static ObjectMapper createMapper(JsonFactory factory) {
         // Ensure enums are properly validated (not just numeric values)
         mapper.configure(DeserializationFeature.FAIL_ON_NUMBERS_FOR_ENUMS, true);
 
+        // Accept enum values in any case ("no_ocr" as well as "NO_OCR"): hand-written
+        // requests and older examples spell them either way
+        mapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_ENUMS, true);
+
         // Catch duplicate keys in JSON objects
         mapper.configure(DeserializationFeature.FAIL_ON_READING_DUP_TREE_KEY, true);
 

tika-serialization/src/test/java/org/apache/tika/config/loader/TikaObjectMapperFactoryTest.java

@@ -0,0 +1,53 @@
+/*
+ * 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.tika.config.loader;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.exc.InvalidFormatException;
+import org.junit.jupiter.api.Test;
+
+public class TikaObjectMapperFactoryTest {
+
+    enum Strategy {
+        NO_OCR, AUTO
+    }
+
+    static class Config {
+        public Strategy strategy;
+    }
+
+    @Test
+    public void testEnumValuesAreCaseInsensitive() throws Exception {
+        ObjectMapper mapper = TikaObjectMapperFactory.getMapper();
+        assertEquals(Strategy.NO_OCR,
+                mapper.readValue("{\"strategy\":\"no_ocr\"}", Config.class).strategy);
+        assertEquals(Strategy.NO_OCR,
+                mapper.readValue("{\"strategy\":\"NO_OCR\"}", Config.class).strategy);
+        assertEquals(Strategy.AUTO,
+                mapper.readValue("{\"strategy\":\"Auto\"}", Config.class).strategy);
+    }
+
+    @Test
+    public void testUnknownEnumValueStillFails() {
+        ObjectMapper mapper = TikaObjectMapperFactory.getMapper();
+        assertThrows(InvalidFormatException.class,
+                () -> mapper.readValue("{\"strategy\":\"nope\"}", Config.class));
+    }
+}