java父类子类初始化顺序

public class BaseApp<S,E> {
    private final List<S> sources;
    private final List<Location> locations;
    private final List<E> entries;

    public BaseApp(List<S> sources, List<Location> locations, List<E> entries) {
        this.sources = sources;
        this.locations = locations;
        this.entries = entries;
    }
}
public class FlightScheduleApp extends BaseApp<Plane, FlightEntry> {
    private final List<Plane> sources=new ArrayList<>();
    private final List<Location> locations=new ArrayList<>();
    private final List<FlightEntry> entries=new ArrayList<>();

    public FlightScheduleApp() {
        //Cannot reference 'FlightScheduleApp.sources' before supertype constructor has been called
        super(sources,locations,entries);
    }
}

/**
 * 父类
 */
public class Base {

    static String sVar = getString("父类静态变量初始化");
    public String var = getString("父类非静态变量初始化");

    public Base() {
        System.out.println("父类构造函数 start");
        draw("父类调用draw方法");//会调用子类覆盖后的方法，这里是null
        System.out.println("父类构造函数 end");
    }

    static String getString(String base) {
        System.out.println(base);
        return base;
    }

    public void draw(String string) {
        System.out.println(string);
    }
}

/**
 * 子类
 */
public class SubClass extends Base {

    public String var = getString("子类非静态变量初始化");
    private String subVar = getString("子类私有变量初始化");
    static String superVar = getString("子类静态变量初始化");

    SubClass() {
        System.out.println("子类构造函数start");
        draw("子类调用draw方法");
        System.out.println("子类构造函数end");
    }

    public void draw(String string) {
        System.out.println(string + subVar);
    }

    public static void main(String[] args) {
        new SubClass();
    }
}