Java获取泛型真实类型的方法

获取泛型类的泛型

public abstract class AbstractDao<T> {
    public Class<T> getActualType() {
        ParameterizedType parameterizedType = (ParameterizedType) ().getGenericSuperclass();
        return (Class<T>) ()[0];
    }
}

public class UserDao extends AbstractDao<String> {
    public static void main(String[] args) {
        UserDao userDao = new UserDao();
        Class<String> actualType = ();
        (());
    }
}

获取成员变量的泛型

public class User {
    private List<String> list;
    public static void main(String[] args) {
        try {
            Field field = ("list");
            Type genericType = ();
            if (genericType != null && genericType instanceof ParameterizedType) {
                Type actualType = ((ParameterizedType) genericType).getActualTypeArguments()[0];
                (());
            }
        } catch (Exception e) {
        }
    }
}

获取局部变量的泛型，注意：泛型必须以匿名内部类的方式

public abstract class AbstractDao<T> {

    public Class<T> getActualType() {
        ParameterizedType parameterizedType = (ParameterizedType) ().getGenericSuperclass();
        return (Class<T>) ()[0];
    }

    public static void main(String[] args) {
        AbstractDao<String> dao = new AbstractDao<String>() {
        };
        (().getTypeName());
    }
}