//Use a try with resources so that the scanner is closed on completion
 int maleCount = 0;
 int femaleCount = 0;
 try (Scanner scanner = new Scanner(f)) {

    while (scanner.hasNextLine()) {
        String line = scanner.nextLine();
        //TODO Check line is not empty whitespace... A good way of doing this is to use StringUtils.isBlank() in Apache Commons
        if (line.length() == 0) {
              //What to do?
        }
        String[] parts = line.split(" ");
        if (parts.length != 2) {
             //What do you want to do with an invalid line? Skip it? End program?
        } else {
            //wrap in a try catch - what if parts[X] isn't a number?
            //Or check the string contains only digits before parsing using StringUtils.isNumeric() which is part of Apache Commons 
            femaleCount += Integer.parseInt(parts[0]);
            maleCount += Integer.parseInt(parts[1]);
        }
    }
}
//Use the counts

如果您在方法中有这个，您可以从apachecommons返回一个immutablepair中的计数(https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/tuple/immutablepair.html)

首先，我更喜欢退货 List 接口到 ArrayList 具体类型，第二次声明（并初始化）您的 List 两个整数值（分别代表女性和男性模拟市民）。使用 try-with-Resources 以避免内存泄漏 Scanner （或显式关闭）。读取文件中的每一行，在空白处拆分并解析两个int值。将它们添加到各自的运行总数中。归还 List . 比如，

public static List<Integer> simCity(File f) throws FileNotFoundException {
    // Start with a List of femaleCounts = 0, maleCounts = 0
    List<Integer> totals = new ArrayList<>(Arrays.asList(0, 0));
    try (Scanner scanner = new Scanner(f)) {
        while (scanner.hasNextLine()) {
            String line = scanner.nextLine();
            // Skip empty lines
            if (line.isEmpty()) {
                continue;
            }
            // Tokenize the line
            String[] tokens = line.split("\\s+");
            // Add the line count of females
            totals.set(0, Integer.parseInt(tokens[0]) + totals.get(0));
            // Add the line count of males
            totals.set(1, Integer.parseInt(tokens[1]) + totals.get(1));
        }
    }
    // Return the List of femaleCounts, maleCounts
    return totals;
}

也许，定义一个自定义计数器类型会更好。这样你就可以 female 以及 male 独立于任何 List ，并使代码更易于推理。它甚至可以包含解析和加法逻辑！例如，

class SimCounter {
    private int female;
    private int male;

    public SimCounter(int female, int male) {
        this.female = female;
        this.male = male;
    }

    public void add(SimCounter sc) {
        this.female += sc.female;
        this.male += sc.male;
    }

    public int getFemale() {
        return female;
    }

    public int getMale() {
        return male;
    }

    public String toString() {
        return String.format("%d %d", female, male);
    }

    public static SimCounter parse(String line) {
        String[] tokens = line.split("\\s+");
        return new SimCounter(Integer.parseInt(tokens[0]), 
                Integer.parseInt(tokens[1]));
    }
}

然后您的方法可以实现为

public static SimCounter simCity(File f) throws FileNotFoundException {
    SimCounter counter = new SimCounter(0, 0);
    try (Scanner scanner = new Scanner(f)) {
        while (scanner.hasNextLine()) {
            counter.add(SimCounter.parse(scanner.nextLine()));
        }
    }
    return counter;
}