java: unable to override protected methods

[eladb]

🐛 Bug Report

Affected Languages

• TypeScript or Javascript
• Python
• Java
• .NET (C#, F#, ...)

General Information

• JSII Version: 0.19.0
• Platform: any

What is the problem?

When trying to override a protected jsii method in Java, the following error is printed:

software.amazon.jsii.JsiiException: Resolution error: Unable to find callback method with signature: protected java.lang.String com.amazon.noopf.tenantresourcegenrator.NoOpfStack.allocateLogicalId(software.amazon.awscdk.core.CfnElement).

An example would be to try and override the allocateLogicalId method in a subclass of @aws-cdk/core.Stack:

public class MyStack extends Stack {
    private final String STACK_MAJOR_VERSION = "v1";

    public MyStack(App parent, String name, MyStackProps props) {
        super(parent, name, props);
        //CfnResource cfnResource = new CfnResource(...);
        //...
    }

    @Override
    protected String allocateLogicalId(CfnElement cfnElement) {
        return super.allocateLogicalId(cfnElement) + STACK_MAJOR_VERSION;
    }
}

Workaround

A workaround (credits @RomainMuller) is to change the override from protected to public.