(Java) 如何将 CSV 文件的一列映射到不同类型的另一列？

Question

所以对于这个问题，我的函数应该是 return 出场次数最多的前 10 名复仇者名单（在递减顺序）。
在 Avenger class 中，它很像基本的 Person class 但是没有 getter 函数，只有代表他们的姓名、性别、外貌的字段，等等

public class Avenger {
    public final String name;
    public final int appearances;
    public final String gender;
    public final int year;
    public final String honorary;
    public final String[] deaths;
    public final String[] returns;
    public final String notes;

    public Avenger(String name,
                   int appearances,
                   String gender,
                   int year,
                   String honorary,
                   String[] deaths,
                   String[] returns,
                   String notes) {
        this.name = name;
        this.appearances = appearances;
        this.gender = gender;
        this.year = year;
        this.honorary = honorary;
        this.deaths = deaths;
        this.returns = returns;
        this.notes = notes;
    }

    public static Avenger valueOf(String line) {
        String[] array = line.split(",");
        String name = array[0];
        int appearances = Integer.valueOf(array[1]);
        String gender = array[2];
        int year = Integer.valueOf(array[3]);
        String honorary = array[4];
        String[] deaths = new String[5];
        String[] returns = new String[5];
        String notes = array[15];

        int index = 5;
        int i = 0;
        while (index < 15) {
            deaths[i] = array[index++];
            returns[i] = array[index++];
            i++;
        }
        return new Avenger(name, appearances, gender, year, honorary, deaths, returns, notes);
    }

    @Override
    public String toString() {
        return "Avenger [name=" + name + ", appearances=" + appearances + ", gender=" + gender + ", year=" + year
                + ", honorary=" + honorary + ", deaths=" + Arrays.toString(deaths) + ", returns="
                + Arrays.toString(returns) + ", notes=" + notes + "]";
    }
}

我的函数是获取顶部 10 APPEARANCES，它 returning 的数字是正确的。

static Function<Stream<Avenger>, List<String>> getTop10ByAppearances = a -> 
a.map(s -> s.appearances).sorted((x, y) -> y - x).limit(10)
.map(p -> p.toString()).collect(Collectors.toList());

但是，我不需要它 return 数字，我需要它 return 与那些数字相对应的 NAMES。所以我的问题是如何将我这里的内容映射到名称，然后 return 这些名称的 List<String>？

Answer 1

我认为只删除第一个 map 操作并像这样执行比较就足够了

sorted(Comparator.comparingInt((Avenger x) -> x.appearances).reversed())

然后，您可以在代码中保留您所做的事情。您限制前 10 个结果，将每个复仇者映射到他们的名字，最后收集结果。

static Function<Stream<Avenger>, List<String>> getTop10ByAppearances = a ->
                a.sorted(Comparator.comparingInt((Avenger x) -> x.appearances).reversed())
                .limit(10)
                .map(p -> p.name)
                .collect(Collectors.toList());

(Java) 如何将 CSV 文件的一列映射到不同类型的另一列？

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