Bump spring-boot-starter-parent from 3.5.6 to 4.0.0 in Spring Batch Notion

spring-batch-notion/.mvn/jvm.config

@@ -0,0 +1,10 @@
+--add-exports jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED
+--add-opens jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED
+--add-opens jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED

spring-batch-notion/README.md

@@ -6,7 +6,7 @@ This project provides a [Spring Batch][] extension module that adds support for
 
 ## Compatibility
 
-Spring Batch Notion is based on Spring Batch 5 and tested on Spring Boot 3, thus requiring at least Java 17.
+Spring Batch Notion is based on Spring Batch 6 and tested on Spring Boot 4, thus requiring at least Java 17.
 
 Compatibility is guaranteed only with the Spring Batch versions under [OSS support](https://spring.io/projects/spring-batch#support). 
 
@@ -36,25 +36,29 @@ A minimal configuration of the item reader is as follows:
 
 ```java
 NotionDatabaseItemReader<Item> itemReader() {
-    NotionDatabaseItemReader<Item> reader = new NotionDatabaseItemReader<>();
-    reader.setToken(System.getenv("NOTION_TOKEN"));
-    reader.setDatabaseId("XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"); // UUID
-    reader.setPropertiesMapper(new CustomPropertyMapper());
-    return reader;
+    String token = System.getenv("NOTION_TOKEN");
+    String databaseId = "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"; // UUID
+    PropertyMapper<Item> propertyMapper = new CustomPropertyMapper();
+    return new NotionDatabaseItemReader<>(token, databaseId, propertyMapper);
 }
 ```
 
-The following configuration options are available:
+The following constructor parameters should be provided:
+
+| Property         | Description                                                                                                               |
+|------------------|---------------------------------------------------------------------------------------------------------------------------|
+| `token`          | The Notion integration token.                                                                                             |
+| `databaseId`     | UUID of the database to read from.                                                                                        |
+| `propertyMapper` | The `PropertyMapper` responsible for mapping properties of a Notion item into a Java object.                              |
+
+and the following configuration options are available:
 
 | Property         | Required | Default                     | Description                                                                                                               |
 |------------------|----------|-----------------------------|---------------------------------------------------------------------------------------------------------------------------|
 | `baseUrl`        | no       | `https://api.notion.com/v1` | Base URL of the Notion API. A custom value can be provided for testing purposes (e.g., the URL of a [WireMock][] server). |
-| `databaseId`     | yes      | -                           | UUID of the database to read from.                                                                                        |
 | `filter`         | no       | `null`                      | `Filter` condition to limit the returned items.                                                                           |
 | `pageSize`       | no       | `100`                       | Number of items to be read with each page. Must be greater than zero and less than or equal to 100.                       |
-| `propertyMapper` | yes      | -                           | The `PropertyMapper` responsible for mapping properties of a Notion item into a Java object.                              |
 | `sorts`          | no       | `null`                      | `Sort` conditions to order the returned items. Each condition is applied following the declaration order.                 |
-| `token`          | yes      | -                           | The Notion integration token.                                                                                             |
 
 In addition to the Notion-specific configuration, all the configuration options of the Spring Batch
 [`AbstractPaginatedDataItemReader`](https://docs.spring.io/spring-batch/docs/current/api/org/springframework/batch/item/data/AbstractPaginatedDataItemReader.html)

spring-batch-notion/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
-    <version>3.5.6</version>
+    <version>4.0.0</version>
     <relativePath/>
   </parent>
 
@@ -160,8 +160,31 @@ limitations under the License.
         <artifactId>maven-compiler-plugin</artifactId>
         <configuration>
           <compilerArgs>
-            <arg>-Xlint:all,-varargs</arg>
+            <compilerArg>-Xlint:all,-varargs</compilerArg>
+            <!-- https://errorprone.info/docs/installation#maven -->
+            <compilerArg>-XDcompilePolicy=simple</compilerArg>
+            <compilerArg>--should-stop=ifError=FLOW</compilerArg>
+            <compilerArg>
+              -Xplugin:ErrorProne
+              -XepDisableAllChecks
+              <!-- Check JSpecify annotations -->
+              -Xep:NullAway
+              -XepOpt:NullAway:OnlyNullMarked
+              -XepOpt:NullAway:SuppressionNameAliases=DataFlowIssue
+            </compilerArg>
           </compilerArgs>
+          <annotationProcessorPaths>
+            <path>
+              <groupId>com.google.errorprone</groupId>
+              <artifactId>error_prone_core</artifactId>
+              <version>2.43.0</version>
+            </path>
+            <path>
+              <groupId>com.uber.nullaway</groupId>
+              <artifactId>nullaway</artifactId>
+              <version>0.12.11</version>
+            </path>
+          </annotationProcessorPaths>
           <failOnWarning>true</failOnWarning>
         </configuration>
       </plugin>
@@ -178,8 +201,8 @@ limitations under the License.
           </additionalDependencies>
           <failOnWarnings>true</failOnWarnings>
           <links>
-            <link>https://docs.spring.io/spring-batch/docs/${spring-batch.version}/api/</link>
             <link>https://docs.spring.io/spring-framework/docs/${spring-framework.version}/javadoc-api/</link>
+            <link>https://javadoc.io/static/org.springframework.batch/spring-batch-core/${spring-batch.version}/</link>
           </links>
         </configuration>
         <executions>

spring-batch-notion/src/main/java/org/springframework/batch/extensions/notion/NotionDatabaseItemReader.java

@@ -25,11 +25,11 @@
 import notion.api.v1.model.pages.PageProperty;
 import notion.api.v1.model.pages.PageProperty.RichText;
 import notion.api.v1.request.databases.QueryDatabaseRequest;
+import org.jspecify.annotations.Nullable;
 import org.springframework.batch.extensions.notion.mapping.PropertyMapper;
-import org.springframework.batch.item.ExecutionContext;
-import org.springframework.batch.item.ItemReader;
-import org.springframework.batch.item.data.AbstractPaginatedDataItemReader;
-import org.springframework.beans.factory.InitializingBean;
+import org.springframework.batch.infrastructure.item.ExecutionContext;
+import org.springframework.batch.infrastructure.item.ItemReader;
+import org.springframework.batch.infrastructure.item.data.AbstractPaginatedDataItemReader;
 import org.springframework.util.Assert;
 
 import java.util.Collections;
@@ -57,39 +57,41 @@
  * @author Stefano Cordio
  * @param <T> Type of item to be read
  */
-public class NotionDatabaseItemReader<T> extends AbstractPaginatedDataItemReader<T> implements InitializingBean {
-
-	private static final String DEFAULT_BASE_URL = "https://api.notion.com/v1";
+public class NotionDatabaseItemReader<T> extends AbstractPaginatedDataItemReader<T> {
 
 	private static final int DEFAULT_PAGE_SIZE = 100;
 
-	private String baseUrl;
+	private static final String DEFAULT_BASE_URL = "https://api.notion.com/v1";
+
+	private final String token;
 
-	private String token;
+	private final String databaseId;
 
-	private String databaseId;
+	private final PropertyMapper<T> propertyMapper;
 
-	private PropertyMapper<T> propertyMapper;
+	private String baseUrl = DEFAULT_BASE_URL;
 
-	private QueryTopLevelFilter filter;
+	private @Nullable QueryTopLevelFilter filter;
 
-	private List<QuerySort> sorts;
+	private @Nullable List<QuerySort> sorts;
 
-	private NotionClient client;
+	private @Nullable NotionClient client;
 
 	private boolean hasMore;
 
-	private String nextCursor;
+	private @Nullable String nextCursor;
 
 	/**
-	 * Create a new {@link NotionDatabaseItemReader} with the following defaults:
-	 * <ul>
-	 * <li>{@code baseUrl} = {@value #DEFAULT_BASE_URL}</li>
-	 * <li>{@code pageSize} = {@value #DEFAULT_PAGE_SIZE}</li>
-	 * </ul>
+	 * Create a new {@link NotionDatabaseItemReader}.
+	 * @param token the Notion integration token
+	 * @param databaseId UUID of the database to read from
+	 * @param propertyMapper the {@link PropertyMapper} responsible for mapping properties
+	 * of a Notion item into a Java object
 	 */
-	public NotionDatabaseItemReader() {
-		this.baseUrl = DEFAULT_BASE_URL;
+	public NotionDatabaseItemReader(String token, String databaseId, PropertyMapper<T> propertyMapper) {
+		this.token = Objects.requireNonNull(token);
+		this.databaseId = Objects.requireNonNull(databaseId);
+		this.propertyMapper = Objects.requireNonNull(propertyMapper);
 		this.pageSize = DEFAULT_PAGE_SIZE;
 	}
 
@@ -106,37 +108,6 @@ public void setBaseUrl(String baseUrl) {
 		this.baseUrl = Objects.requireNonNull(baseUrl);
 	}
 
-	/**
-	 * The Notion integration token.
-	 * <p>
-	 * Always required.
-	 * @param token the token
-	 */
-	public void setToken(String token) {
-		this.token = Objects.requireNonNull(token);
-	}
-
-	/**
-	 * UUID of the database to read from.
-	 * <p>
-	 * Always required.
-	 * @param databaseId the database UUID
-	 */
-	public void setDatabaseId(String databaseId) {
-		this.databaseId = Objects.requireNonNull(databaseId);
-	}
-
-	/**
-	 * The {@link PropertyMapper} responsible for mapping Notion item properties into a
-	 * Java object.
-	 * <p>
-	 * Always required.
-	 * @param propertyMapper the property mapper
-	 */
-	public void setPropertyMapper(PropertyMapper<T> propertyMapper) {
-		this.propertyMapper = Objects.requireNonNull(propertyMapper);
-	}
-
 	/**
 	 * {@link Filter} condition to limit the returned items.
 	 * <p>
@@ -175,6 +146,19 @@ public void setPageSize(int pageSize) {
 		super.setPageSize(pageSize);
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	protected void doOpen() {
+		client = new NotionClient(token);
+		client.setHttpClient(new JavaNetHttpClient());
+		client.setLogger(new Slf4jLogger());
+		client.setBaseUrl(baseUrl);
+
+		hasMore = true;
+	}
+
 	/**
 	 * {@inheritDoc}
 	 */
@@ -190,6 +174,7 @@ protected Iterator<T> doPageRead() {
 		request.setStartCursor(nextCursor);
 		request.setPageSize(pageSize);
 
+		@SuppressWarnings("DataFlowIssue")
 		QueryResults queryResults = client.queryDatabase(request);
 
 		hasMore = queryResults.getHasMore();
@@ -198,7 +183,7 @@ protected Iterator<T> doPageRead() {
 		return queryResults.getResults()
 			.stream()
 			.map(NotionDatabaseItemReader::getProperties)
-			.map(properties -> propertyMapper.map(properties))
+			.map(propertyMapper::map)
 			.iterator();
 	}
 
@@ -224,19 +209,7 @@ private static String getPlainText(List<RichText> texts) {
 	/**
 	 * {@inheritDoc}
 	 */
-	@Override
-	protected void doOpen() {
-		client = new NotionClient(token);
-		client.setHttpClient(new JavaNetHttpClient());
-		client.setLogger(new Slf4jLogger());
-		client.setBaseUrl(baseUrl);
-
-		hasMore = true;
-	}
-
-	/**
-	 * {@inheritDoc}
-	 */
+	@SuppressWarnings("DataFlowIssue")
 	@Override
 	protected void doClose() {
 		client.close();
@@ -255,14 +228,4 @@ protected void jumpToItem(int itemIndex) throws Exception {
 		}
 	}
 
-	/**
-	 * {@inheritDoc}
-	 */
-	@Override
-	public void afterPropertiesSet() {
-		Assert.state(token != null, "'token' must be set");
-		Assert.state(databaseId != null, "'databaseId' must be set");
-		Assert.state(propertyMapper != null, "'propertyMapper' must be set");
-	}
-
 }

spring-batch-notion/src/main/java/org/springframework/batch/extensions/notion/mapping/package-info.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2024-2025 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+/**
+ * Infrastructure to map the properties of a Notion item into a Java object.
+ */
+@NullMarked
+package org.springframework.batch.extensions.notion.mapping;
+
+import org.jspecify.annotations.NullMarked;

spring-batch-notion/src/main/java/org/springframework/batch/extensions/notion/package-info.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2024-2025 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+/**
+ * Spring Batch extension for Notion.
+ */
+@NullMarked
+package org.springframework.batch.extensions.notion;
+
+import org.jspecify.annotations.NullMarked;