Chain of responsibility automatic generator

Question

i have 8 handler class, is there a way i can create the chain dynamically in java?

What I mean, if I have two classes right now like:

HandlerA

HandlerB

HandlerChain

HanddlerChain will create the chain, HandlerA->HandlerB, (using loop read all class names from the folder)

when i add HandlerC then it is automatically add without any interaction and the chain become, HandlerA->HandlerB->HandlerC.

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So if I had String className = "HandlerA"

What is the way i make instance of HandlerA.class using the privaice String?

Answer 1

    File folder = new File("JavaClassesPath");
    ArrayList<String> all = new ArrayList<>();
    for (final File fileEntry : folder.listFiles()) {
        if (!fileEntry.isDirectory()) {
            all.add(fileEntry.getName().substring(0, fileEntry.getName().lastIndexOf('.')));
        }
    }

    String className = "PackageName";

    for (String s: all) {
        if (!s.equals("AbstractClassName")) {
            Class<?> clazz = Class.forName(className + '.' + s);
            Constructor<?> ctor = clazz.getConstructor();
            Object object = ctor.newInstance();
            allHandlers.add((RequestHandler) object);
        }
    }

    for(int i=0; i<allHandlers.size()-1; i++){
        allHandlers.get(i).setNextHandler(allHandlers.get(i+1));
    }