How to access the loaded config properties from extended BuildStepDescriptor?

Using Jenkins
1

Jenkins setup:-

Plugin development Environment
version 1.25 archetype

I want to try develop a test tracking post-action plugin,and the form “f:select” is bind to user’s accessible project id,which I want to fetch from remote uri in plugin inside.

Since @DataBoundConstructor will inject the pre-configured paramters to the class which extends hudson.tasks.Recorder, But I’m not sure how to get these saved parameters in the DescriptorImpl class which extends BuildStepDescriptor<Publisher>

    @Extension
    public static final class DescriptorImpl extends BuildStepDescriptor<Publisher> {
        public DescriptorImpl() {
            load();
// load the config,then how to get paramters?
        }

        public String getCurrentUser() {
            Optional<User> currentUser = Optional.ofNullable(User.current());
            if (currentUser.isPresent()) {
                return currentUser.get().getId();
            } else {
                return "anonymous";
            }
        }

        @Override
        public boolean isApplicable(Class<? extends AbstractProject> jobType) {
            return true;
        }

        public ListBoxModel doFillTestProjectItems() {
            ListBoxModel items = new ListBoxModel();
            items.add("I WANT TO ADD THE PRE-CONFIGURED DATA")
            return items;
        }
// ...
}

Any suggestions?