Parse a string and return a list of values

I want to create a custom java action that parses a string on some delimiter and returns a List of the parsed values. I have an Invoice entity with an InvoiceID attribute. 

My goal is to take a string of invoices like "44 55 66" and return the members of the SearchStringSplitResult entity with InvoiceID = 44, 55 or 66. Then I think I'll be able to create an association between SearchStringSplitRsult and Invoice that will allow me to return an Invoice list.

This is the code for my java action:

// This file was generated by Mendix Modeler.
//
// WARNING: Only the following code will be retained when actions are regenerated:
// - the import list
// - the code between BEGIN USER CODE and END USER CODE
// - the code between BEGIN EXTRA CODE and END EXTRA CODE
// Other code you write will be lost the next time you deploy the project.
// Special characters, e.g., é, ö, à, etc. are supported in comments.

package myfirstmodule.actions;

import com.mendix.systemwideinterfaces.core.IContext;
import com.mendix.webui.CustomJavaAction;
import com.mendix.systemwideinterfaces.core.IMendixObject;
import java.util.List;
import java.util.ArrayList;

public class SplitString extends CustomJavaAction<java.util.List<IMendixObject>>
{
	private java.lang.String StringToSplit;
	private java.util.List<IMendixObject> __SearchStringSplitResultList;
	private java.util.List<myfirstmodule.proxies.SearchStringSplitResult> SearchStringSplitResultList;

	public SplitString(IContext context, java.lang.String StringToSplit, java.util.List<IMendixObject> SearchStringSplitResultList)
	{
		super(context);
		this.StringToSplit = StringToSplit;
		this.__SearchStringSplitResultList = SearchStringSplitResultList;
	}

	@Override
	public java.util.List<IMendixObject> executeAction() throws Exception
	{
		this.SearchStringSplitResultList = new java.util.ArrayList<myfirstmodule.proxies.SearchStringSplitResult>();
		if (__SearchStringSplitResultList != null)
			for (IMendixObject __SearchStringSplitResultListElement : __SearchStringSplitResultList)
				this.SearchStringSplitResultList.add(myfirstmodule.proxies.SearchStringSplitResult.initialize(getContext(), __SearchStringSplitResultListElement));

		// BEGIN USER CODE
		String[] splitArray = StringToSplit.split("");

		for (String splitStringElement : splitString){
			List<myfirstmodule.proxies.SearchStringSplitResult> ResultList = new ArrayList<myfirstmodule.proxies.SearchStringSplitResult>();

		}
		// END USER CODE
	}

	/**
	 * Returns a string representation of this action
	 */
	@Override
	public java.lang.String toString()
	{
		return "SplitString";
	}

	// BEGIN EXTRA CODE
	// END EXTRA CODE
}