java 泛型匹配

public class App {
    public static void main(String[] args) {
        test(new ArrayList<String>());
        test(new ArrayList<Integer>());
    }

    public static void test(List<String> strings, String... a) {
        System.out.println("strings");
    }

    public static void test(List<Integer> integers, Integer... a) {
        System.out.println("integers");
    }
}

群友讨论中学到的, 原因是不定参在编译后会自动带空参数, 如以上代码会被编译为:

public class App {
    public App() {
    }

    public static void main(String[] args) {
        test(new ArrayList(), (String[])());
        test(new ArrayList(), (Integer[])());
    }

    public static void test(List<String> strings, String... a) {
        System.out.println("strings");
    }

    public static void test(List<Integer> integers, Integer... a) {
        System.out.println("integers");
    }
}