Update default configuration of Jackson 3 mapper in JacksonJsonObjectReader

The default value of DeserializationFeature.FAIL_ON_TRAILING_TOKENS has
changed from false to true in Jackson 3. This change requires users to
disable that feature to be able to use Spring Batch's JsonItemReader
correctly.

This commit disables that feature by default in JacksonJsonObjectReader
so that Spring Batch users do not have to do it manually.

Resolves #5047

Author: fmbenhassine

spring-batch-infrastructure/src/main/java/org/springframework/batch/infrastructure/item/json/JacksonJsonObjectReader.java

@@ -21,6 +21,7 @@
 import tools.jackson.core.JacksonException;
 import tools.jackson.core.JsonParser;
 import tools.jackson.core.JsonToken;
+import tools.jackson.databind.DeserializationFeature;
 import tools.jackson.databind.json.JsonMapper;
 import org.jspecify.annotations.Nullable;
 
@@ -47,13 +48,26 @@ public class JacksonJsonObjectReader<T> implements JsonObjectReader<T> {
 	private @Nullable InputStream inputStream;
 
 	/**
-	 * Create a new {@link JacksonJsonObjectReader} instance.
+	 * Create a new {@link JacksonJsonObjectReader} instance. This will initialize the
+	 * reader with a default {@link JsonMapper} having
+	 * {@link DeserializationFeature#FAIL_ON_TRAILING_TOKENS} and
+	 * {@link DeserializationFeature#FAIL_ON_NULL_FOR_PRIMITIVES} disabled by default. If
+	 * you want to customize the mapper, use
+	 * {@link #JacksonJsonObjectReader(JsonMapper, Class)}.
 	 * @param itemType the target item type
 	 */
 	public JacksonJsonObjectReader(Class<? extends T> itemType) {
-		this(new JsonMapper(), itemType);
+		this(JsonMapper.builder()
+			.disable(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)
+			.disable(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES)
+			.build(), itemType);
 	}
 
+	/**
+	 * Create a new {@link JacksonJsonObjectReader} instance.
+	 * @param mapper the json mapper to use
+	 * @param itemType the target item type
+	 */
 	public JacksonJsonObjectReader(JsonMapper mapper, Class<? extends T> itemType) {
 		this.mapper = mapper;
 		this.itemType = itemType;

spring-batch-infrastructure/src/test/java/org/springframework/batch/infrastructure/item/json/JacksonJsonItemReaderCommonTests.java

@@ -16,9 +16,6 @@
 
 package org.springframework.batch.infrastructure.item.json;
 
-import tools.jackson.databind.DeserializationFeature;
-import tools.jackson.databind.json.JsonMapper;
-
 import org.springframework.batch.infrastructure.item.sample.Foo;
 
 /**
@@ -28,11 +25,7 @@ class JacksonJsonItemReaderCommonTests extends JsonItemReaderCommonTests {
 
 	@Override
 	protected JsonObjectReader<Foo> getJsonObjectReader() {
-		JsonMapper jsonMapper = JsonMapper.builder()
-			.disable(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES)
-			.disable(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)
-			.build();
-		return new JacksonJsonObjectReader<>(jsonMapper, Foo.class);
+		return new JacksonJsonObjectReader<>(Foo.class);
 	}
 
 }

spring-batch-infrastructure/src/test/java/org/springframework/batch/infrastructure/item/json/JacksonJsonItemReaderFunctionalTests.java

@@ -17,8 +17,6 @@
 package org.springframework.batch.infrastructure.item.json;
 
 import tools.jackson.core.JacksonException;
-import tools.jackson.databind.DeserializationFeature;
-import tools.jackson.databind.json.JsonMapper;
 
 import org.springframework.batch.infrastructure.item.json.domain.Trade;
 
@@ -29,11 +27,7 @@ class JacksonJsonItemReaderFunctionalTests extends JsonItemReaderFunctionalTests
 
 	@Override
 	protected JsonObjectReader<Trade> getJsonObjectReader() {
-		JsonMapper jsonMapper = JsonMapper.builder()
-			.disable(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES)
-			.disable(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)
-			.build();
-		return new JacksonJsonObjectReader<>(jsonMapper, Trade.class);
+		return new JacksonJsonObjectReader<>(Trade.class);
 	}
 
 	@Override