Java Help.

I have an array like is:

And the arrays have a constructor that all do the same thing, get a file and puts them into a hashmap (All the constructors have a different file to open but and are similar to this):

I'm supposed to calculate which service (hashmap) has the lowest average and highest average, but can't see how to put the priceForTicker (in the interface )function to work in an array:

I'll appreciate the help, here my code to better understand:

import java.io.FileReader;

import java.io.IOException;

import java.util.Map;

import java.util.Scanner;

import java.util.HashMap;

public class Main {

////////////////////////////////////////////////////////////////////////////////////////////

public interface StockPriceService{

double priceForTicker(String ticker);

String nameOfService();

}

////////////////////////////////////////////////////////////////////////////////////////////

static public class NLPService implements StockPriceService{

private HashMap tickerPrices = new HashMap();

public NLPService() throws IOException {

String ticker;

Double price;

Scanner scanner = new Scanner(new FileReader("NLPService.txt"));

while(scanner.hasNext())

{

ticker = scanner.next();

price = scanner.nextDouble();

tickerPrices.put(ticker, price);

}

scanner.close();

}

@Override

public double priceForTicker(String ticker) {

// TODO Auto-generated method stub

if(tickerPrices.get(ticker) == null)

return 0;

else

return tickerPrices.get(ticker);

}

@Override

public String nameOfService() {

// TODO Auto-generated method stub

return "NLP";

}

}

////////////////////////////////////////////////////////////////////////////////////////////

static public class UHStockService implements StockPriceService{

private HashMap tickerPrices = new HashMap();

public UHStockService() throws IOException {

String ticker;

Double price;

Scanner scanner = new Scanner(new FileReader("UHStockService.txt"));

while(scanner.hasNext())

{

ticker = scanner.next();

price = scanner.nextDouble();

tickerPrices.put(ticker, price);

}

scanner.close();

}

@Override

public double priceForTicker(String ticker) {

// TODO Auto-generated method stub

if(tickerPrices.get(ticker) == null)

return 0;

else

return tickerPrices.get(ticker);

}

@Override

public String nameOfService() {

// TODO Auto-generated method stub

return "UH";

}

}

////////////////////////////////////////////////////////////////////////////////////////////

static public class ExternalService implements StockPriceService{

private HashMap tickerPrices = new HashMap();

public ExternalService () throws IOException {

String ticker;

Double price;

Scanner scanner = new Scanner(new FileReader("ExternalService.txt"));

while(scanner.hasNext())

{

ticker = scanner.next();

price = scanner.nextDouble();

tickerPrices.put(ticker, price);

}

scanner.close();

}

@Override

public double priceForTicker(String ticker) {

// TODO Auto-generated method stub

if(tickerPrices.get(ticker) == null)

return 0;

else

return tickerPrices.get(ticker);

}

@Override

public String nameOfService() {

// TODO Auto-generated method stub

return "External";

}

}

////////////////////////////////////////////////////////////////////////////////////////////

static public class StockMachine {

private StockPriceService[] stockPriceServices;

private String[] tickerSymbols;

public StockMachine(String fileName) throws IOException {

stockPriceServices = new StockPriceService[3];

stockPriceServices[0] = new UHStockService();

stockPriceServices[1] = new NLPService();

stockPriceServices[2] = new ExternalService();

}

public String getServiceWithLowestAvg() {

double sum;

for(int i = 0; i

priceForTicke(stockPriceServices[i].get());

}

}

////////////////////////////////////////////////////////////////////////////////////////////

public static void main(String[] args) throws IOException {

// TODO Auto-generated method stub

}

}

static public class StockMachine private StockPriceService[] stockPriceServices; private String[] tickerSymbols; public StockMachine (String fileName) throws IOException{ stockPriceservices - new StockPriceService[3]: stockPriceServices []-new UHStockService() stockPriceServices [1] = new NLPService(); stockPriceServices [2] ce(); new Externalservi