AlgorithmBasic.java

package com.org.example;

import java.util.HashMap;

/**
 * Hello world!
 *
 */
class AlgorithmBasic
{
    String foo(String input, HashMap<String, String> l) throws RuntimeException{
        return "hello ".concat(input);
    }

    Integer bar() throws RuntimeException{
        return 1;
    }

    public static void main(String[] args) throws Exception{
        AlgorithmBasic defs = new AlgorithmBasic();
        AlgorithmHandler algo = new AlgorithmHandler<>(defs::foo);
        algo = algo.setLoad(defs::bar);
        algo.run();
    }
}

AlgorithmHandler.java

package com.org.example;

import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.function.Supplier;


public class AlgorithmHandler<INPUT, STATE, OUTPUT> {


    private BiFunction<INPUT, STATE, OUTPUT> applyFuncState;
    private Supplier<STATE> loadFunc;
    private STATE state;
    
    public AlgorithmHandler(BiFunction<INPUT,STATE, OUTPUT> applyFunc, Supplier<STATE> loadFunc){
        this.applyFuncState = applyFunc;
        this.loadFunc = loadFunc;
    }

    public AlgorithmHandler(BiFunction<INPUT, STATE, OUTPUT> applyFunc) throws Exception{

        this.applyFuncState = applyFunc;
    }

    public AlgorithmHandler setLoad(Supplier<STATE> func) throws Exception{
        loadFunc = func;
        return this;
    }
    public void run() throws Exception{
        System.out.println("Not implemented");
    }

}