java/W8/TestGeneric.java

import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;

public class GenericReflectDemo {
    // 成员变量带泛型
    private List<String> list;

    public static void main(String[] args) throws NoSuchFieldException {
        // 1. 获取成员变量的泛型类型
        Field field = GenericReflectDemo.class.getDeclaredField("list");
        Type genericType = field.getGenericType();
        if (genericType instanceof ParameterizedType) {
            ParameterizedType pType = (ParameterizedType) genericType;
            Type[] actualTypeArgs = pType.getActualTypeArguments();
            for (Type arg : actualTypeArgs) {
                System.out.println("泛型参数类型：" + arg); // 输出 class java.lang.String
            }
        }

        // 2. 获取父类的泛型参数
        class MyList extends ArrayList<String> {}
        Type superType = MyList.class.getGenericSuperclass();
        if (superType instanceof ParameterizedType) {
            ParameterizedType pType = (ParameterizedType) superType;
            System.out.println("父类泛型参数：" + pType.getActualTypeArguments()[0]);
        }
    }
}