build with jdk17

Author: rbri

README.md

@@ -18,6 +18,26 @@ We will try to stay in sync with CSSParser regarding the features in the future.
 
 [HtmlUnit@mastodon](https://fosstodon.org/@HtmlUnit) | [HtmlUnit@bsky](https://bsky.app/profile/htmlunit.bsky.social) | [HtmlUnit@Twitter](https://twitter.com/HtmlUnit)
 
+#### Version 5
+
+Work on HtmlUnit-CSSParser 5.0 has started. This new major version will require **JDK 17 or higher**.
+
+
+#### Legacy Support (JDK 8)
+
+If you need to continue using **JDK 8**, please note that versions 4.x will remain available as-is. However,
+**ongoing maintenance and fixes for JDK 8 compatibility are only available through sponsorship**.
+
+Maintaining separate fix versions for JDK 8 requires significant additional effort for __backporting__, testing, and release management.
+
+**To enable continued JDK 8 support**, please contact me via email to discuss sponsorship options. Sponsorship provides:
+
+- __Backporting__ security and bug fixes to the 4.x branch
+- Maintaining compatibility with older Java versions
+- Timely releases for critical issues
+
+Without sponsorship, the 4.x branch will not receive updates. Your support ensures the long-term __sustainability__ of this project across multiple Java versions.
+
 ### Latest release Version 4.21.0 / December 28, 2025
 
 ## Get it!
@@ -161,3 +181,17 @@ This project is licensed under the Apache 2.0 License
 ## Acknowledgments
 
 Many thanks to all of you contributing to HtmlUnit/CSSParser/Rhino in the past.
+
+## Development Tools
+
+Special thanks to:
+
+<a href="https://www.jetbrains.com/community/opensource/"><img src="https://resources.jetbrains.com/storage/products/company/brand/logos/jb_beam.svg" alt="JetBrains" width="42"></a>
+<a href="https://www.jetbrains.com/idea/"><img src="https://resources.jetbrains.com/storage/products/company/brand/logos/IntelliJ_IDEA_icon.svg" alt="IntelliJ IDEA" width="42"></a>  
+**[JetBrains](https://www.jetbrains.com/)** for providing IntelliJ IDEA under their [open source development license](https://www.jetbrains.com/community/opensource/) and
+
+<a href="https://www.eclipse.org/"><img src="https://www.eclipse.org/eclipse.org-common/themes/solstice/public/images/logo/eclipse-foundation-grey-orange.svg" alt="Eclipse Foundation" width="80"></a>  
+Eclipse Foundation for their Eclipse IDE
+
+<a href="https://www.syntevo.com/smartgit/"><img src="https://www.syntevo.com/assets/images/logos/smartgit-8c1aa1e2.svg" alt="SmartGit" width="54"></a>  
+to **[Syntevo](https://www.syntevo.com/)** for their excellent [SmartGit](https://www.smartgit.dev/)!

pom.xml

@@ -4,7 +4,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>org.htmlunit</groupId>
     <artifactId>htmlunit-cssparser</artifactId>
-    <version>4.21.0</version>
+    <version>5.0.0-SNAPSHOT</version>
     <name>HtmlUnit CSS Parser</name>
     <organization>
         <name>HtmlUnit</name>
@@ -17,16 +17,17 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.build.timestamp.format>yyyy-MM-dd HH:mm</maven.build.timestamp.format>
 
-        <maven.compiler.source>8</maven.compiler.source>
-        <maven.compiler.target>8</maven.compiler.target>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+
+        <maven.version.ignore>(?i).*-(alpha|beta|m|rc)([\.-]?\d+)?</maven.version.ignore>
 
         <!-- test dependencies -->
-        <junit.version>5.14.1</junit.version>
-        <junit-launcher.version>1.14.1</junit-launcher.version>
+        <junit.version>6.0.2</junit.version>
         <commons-io.version>2.21.0</commons-io.version>
 
         <!-- quality -->
-        <checkstyle.version>12.3.0</checkstyle.version>
+        <checkstyle.version>13.0.0</checkstyle.version>
         <dependencycheck.version>10.0.4</dependencycheck.version>
 
         <!-- plugins -->
@@ -60,7 +61,7 @@
                                     <version>3.6.3</version>
                                 </requireMavenVersion>
                                 <requireJavaVersion>
-                                    <version>1.8.0</version>
+                                    <version>17</version>
                                 </requireJavaVersion>
                             </rules>
                         </configuration>
@@ -365,7 +366,7 @@
         <dependency>
             <groupId>org.junit.platform</groupId>
             <artifactId>junit-platform-launcher</artifactId>
-            <version>${junit-launcher.version}</version>
+            <version>${junit.version}</version>
             <scope>test</scope>
         </dependency>
         <dependency>