JEP 486: Permanently Disable the Security Manager

https://openjdk.org/jeps/486 <— here more info what replaces SecurityManager

Try to add

System.setSecurityManager(new SecurityManager());

🔍 What the SecurityManager did

It allowed:

• Fine-grained permission checks (file, network, reflection, etc.)

• User-defined security policies via .policy files

• Applet sandboxing (run untrusted code safely)

But it had major problems:

• Too complex to configure

• Often bypassed or misunderstood

• Hard to test and debug

• Didn't align with modern deployment (e.g. containers, microservices)

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✅ What replaces it (functionally)?

Layer	Tool / Concept
OS Level	SELinux, seccomp, AppArmor
Container	Docker, Kubernetes, cgroups
JVM Level	JPMS (--limit-modules), custom agents
Build Level	JLink, JDeps to create minimized runtimes
Dev Level	Static analysis, sealed classes, final