Application Fails to Start in Development/Deployment Mode

[tech0priyanshu]

When I run the project in Development mode:

$ mvn spring-boot:run
$ node node_modules/.bin/webpack --env.NODE_ENV=dev --watch

Issue Log:

When I run the project in Deployment mode:

$ mvn clean install
$ java $JAVA_OPTS -Dserver.port=$PORT -jar target/*.jar

Issue Log:

Environment Details:

Maven Version: 3.8.7

Node Version: v22.14.0

NPM/Yarn Version: 10.9.2

[himeshpathai]

I encountered this issue while running a Spring Boot 1.5.2 project on Java 17.

Environment: Java: 17.x Maven: 3.8.7 Node: v22.14.0 NPM: 10.9.2 Spring Boot: 1.5.2.RELEASE Spring Framework: 4.3.7.RELEASE

Error: java.lang.reflect.InaccessibleObjectException: Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(...) because module java.base does not "opens java.lang" to unnamed module This happens because Spring Boot 1.5.x and Spring Framework 4.x rely on CGLIB reflection that’s blocked by Java 17’s module system.

Workarounds I tried:

Running with: mvn spring-boot:run -Dspring-boot.run.jvmArguments="--add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/java.lang.reflect=ALL-UNNAMED" → Works, but only as a temporary hack.

Downgrading to Java 8 → Works, but not ideal.

Permanent Fix: Upgrade to Spring Boot 2.7.x (or newer) which is fully Java 17 compatible. This also updates Spring Framework to 5.x and removes the need for --add-opens.