Stocks.java

import org.apache.commons.io.IOUtils;

import java.io.IOException;
import java.net.URL;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
import static java.util.AbstractMap.SimpleEntry;

public class Stocks {
    public static void main(String[] args) {
        List<String> symbols = Arrays.asList("AAPL", "GOOG", "IBM", "JAVA", "MSFT");
        int year = 2008;

        SimpleEntry<String, Float> topStock = getTopStock(symbols, year);

        System.out.println("Top stock of " + year + " is " + topStock.getKey() + " closing at price " + topStock.getValue());
    }

    private static SimpleEntry<String, Float> getTopStock(List<String> symbols, int year) {
        return symbols.parallelStream()
                .map(symbol -> getYearEndClosing(symbol, year))
                .reduce((highest, price) -> price.getValue() > highest.getValue() ? price : highest)
                .get();
    }

    private static SimpleEntry<String, Float> getYearEndClosing(String symbol, int year) {
        try {
            String uri = "http://ichart.finance.yahoo.com/table.csv?s=" + symbol + "&a=11&b=01&c=" + year + "&d=11&e=31&f=" + year + "&g=m";
            List<String> data = IOUtils.readLines(new URL(uri).openStream()).stream().map(String::trim).collect(Collectors.toList());
            return new SimpleEntry<>(symbol, Float.parseFloat(data.get(1).split(",")[4]));
        } catch (IOException e) {
            return new SimpleEntry<>(symbol, 0F);
        }
    }
}