JSP Expression Language: Variable input arguments and custom methods declaration

ELEntity.java

package com.example;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

/**
 * Extend this class to implement a server side method that takes arguments that
 * you would like to call via expression language.
 *
 * EL call example: ${elEntity[arg1][arg2][argN].method}
 */
public abstract class ELEntity extends HashMap<Object, Object> {

    private static final Logger log = LoggerFactory.getLogger(ELEntity.class);

    protected List<Object> args = new ArrayList<Object>();

    /**
     * A new argument to add or a method to execute
     * @param key
     * @return Itself if an argument has been added or the
     * result of a method execution
     */
    @Override
    public Object get(Object key) {
        if(key instanceof String){
            Method method = getMethod((String)key);
            if(method != null){
                return this.executeMethod(method);
            }
        }
        this.args.add(key);
        return this;
    }

    public ELEntity reset(){
        args = new ArrayList<Object>();
        return this;
    }

    protected Method getMethod(String name){
        Method method  = null;
        if(StringUtils.isNotEmpty(name)){
            try {
                method = this.getClass().getMethod(name, null);
            } catch (NoSuchMethodException e) {
            }
        }
        return method;
    }

    protected Object executeMethod(Method method){
        Object result = null;
        try {
            result = method.invoke(this, null);
        } catch (IllegalAccessException e) {
            log.error("Illegal access on method execution, method:" + method.getName(), e);
        } catch (InvocationTargetException e) {
            log.error("Invocation error on method execution, method:" + method.getName(), e);
        }
        this.reset();
        return result;
    }
}

ELListBuilder.java

package com.example;

import java.util.ArrayList;
import java.util.List;

public class ELListBuilder extends ELEntity {

    public List build() {
        return new ArrayList(args);
    }
}

view.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jstl/core_rt" %>

...

<jsp:useBean id="listBuilder" class="com.example.ELListBuilder"/>


<ul>
  <c:forEach var="item" items="${listBuilder['red']['yellow']['green'].build}">
      <li>${item}</li>
  </c:forEach>
</ul>

...