泛型父类中获取子类的泛型，延伸工具类-蒲公英云

泛型父类中获取子类的泛型，延伸工具类

小灰灰 2022-09-01 08:30 289阅读 0赞

接口：

public interface Convertable<T,R> extends Serializable {
    /**
     * 转换为R对象
     */
    R convertTo() throws Exception;
    /**
     * T对象赋值
     */
    void convertFor(R r) throws Exception;
}

接口实现：

public abstract class ConvertableImpl<T, R> implements Convertable<T, R> {
    /**
     * 将R转换为T类型
     */
    @Override
    public R convertTo() throws Exception {
        Class<R> classR = null;
        Type genericSuperclass = this.getClass().getGenericSuperclass();
        if (genericSuperclass instanceof ParameterizedType) {
            ParameterizedType parameterizedType = (ParameterizedType) genericSuperclass;
            // size=2，第一个是T，第二个是R
            Type[] actualTypeArguments = parameterizedType.getActualTypeArguments();
            classR = (Class<R>) actualTypeArguments[1];
        }
        R r = classR.newInstance();
        BeanUtils.copyProperties(this, r);
        return r;
    }
    /**
     * T对象赋值
     */
    @Override
    public void convertFor(R r) throws Exception {
        BeanUtils.copyProperties(r, this);
    }
}

DTO：

@Data
public class UserDto extends ConvertableImpl<UserDto, UserPo> {
    private String id;
    private String username;
    private String password;
    private String name;
    private String phone;
}

DO：

@Data
public class UserPo extends ConvertableImpl<UserPo, UserVo> {
    private String id;
    private String username;
    private String password;
    private String name;
    private String phone;
    private Date createTime;
    private Date updateTime;
    private boolean enable;
}

VO：

@Data
public class UserVo {
    private String id;
    private String username;
    private String name;
    private String phone;
}

测试代码：

/**
     * 假设一个正常接口保存流程
     * @param args
     */
    public static void main(String[] args) throws Exception {
        // 1、接口进来的入参
        UserDto dto = new UserDto();
        dto.setName("小明");
        dto.setPhone("12312312313");
        dto.setUsername("xiaoming");
        dto.setPassword("123456");
        // 2、DTO ==》DO
        UserPo po = dto.convertTo();
        po.setCreateTime(new Date());
        po.setUpdateTime(new Date());
        // 3、save po保存成功，回写ID""
        po.setId("1");
        // 4、PO ==》VO
        UserVo vo = po.convertTo();
        System.out.println(vo.getId());
    }