根据不同类型。进入子类

import java.lang.reflect.Constructor;
import java.util.HashMap;
import java.util.Map;

// 基类
public abstract class Base {
    private static final Map<String, Class<? extends Base>> registry = new HashMap<>();

    // 静态方法，用于注册子类
    public static void register(String key, Class<? extends Base> clazz) {
        registry.put(key, clazz);
    }

    // 静态方法，根据key获取并实例化子类
    public static Base getInstance(String key) throws Exception {
        Class<? extends Base> clazz = registry.get(key);
        if (clazz == null) {
            throw new IllegalArgumentException("No class registered with key: " + key);
        }
        
        // 使用无参构造器创建实例
        Constructor<? extends Base> constructor = clazz.getDeclaredConstructor();
        constructor.setAccessible(true); // 如果构造器不是public的，需要设置为可访问
        return constructor.newInstance();
    }

    // 基类的方法，子类可以覆盖
    public void doSomething() {
        System.out.println("Doing something in Base class");
    }
}

// 子类A
public class SubA extends Base {
    static {
        Base.register("SubA", SubA.class);
    }

    @Override
    public void doSomething() {
        System.out.println("Doing something in SubA");
    }
}

// 子类B
public class SubB extends Base {
    static {
        Base.register("SubB", SubB.class);
    }

    @Override
    public void doSomething() {
        System.out.println("Doing something in SubB");
    }
}

// 主类
public class Main {
    public static void main(String[] args) {
        try {
            // 根据key获取并调用子类方法
            Base subA = Base.getInstance("SubA");
            subA.doSomething(); // 输出 "Doing something in SubA"

            Base subB = Base.getInstance("SubB");
            subB.doSomething(); // 输出 "Doing something in SubB"
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}