后台开发中有很多场景需要将数据库实体，Dto，Vo，Param相互转换，有的只是简单的属性拷贝，有的会在这基础上再做写其他的处理，为了避免每次重复开发，使用泛型，开发了一套抽象类抽象共有逻辑

AbstractBean

封装泛型类对象，并提供最基本的属性拷贝方法

class AbstractBean<T> {
  /**
   *  当前泛型真实类型的Class
   */
  private Class<T> modelClass;

  AbstractBean() {
      ParameterizedType pt = (ParameterizedType) this.getClass().getGenericSuperclass();
      modelClass = (Class<T>) pt.getActualTypeArguments()[0];
  }

  T toOtherBean(){
      try {
          T model = modelClass.newInstance();
          BeanUtils.copyProperties(this,model);
          return model;
      } catch (ReflectiveOperationException e) {
          throw new ServiceException(ResultCode.FAIL,e);
      }
  }
 }

AbstractModel/AbstractDto/xxx

基于AbstractBean父类，针对Model和Dto做特殊的泛型限制，并提供模板方法给子类做后续的特殊处理

public abstract class AbstractParam<T extends AbstractDto> extends AbstractBean<T> {
    public T toDto(){
        return super.toOtherBean();
    }
}

public abstract class AbstractDto<T extends IModel> extends AbstractBean<T> {
    public T toModel(){
        return super.toOtherBean();
    }

    public T toModel(Consumer<T> consumer){
        T t = super.toOtherBean();
        consumer.accept(t);
        return t;
    }
}

使用方法

@Data
public class CustomModel implements AbstractModel {

    private Integer id;
    private String name;
    private String idConcatName;
}

@Data
public class CustomDto extends AbstractDto<CustomModel> {
    private Integer id;
    private String name;
}

@Data
public class CustomParam extends AbstractParam<CustomDto> {
    private Integer id;
    private String name;
}

public class Test{
    public static void main(String[] args) {
          CustomParam customParam = new CustomParam();
          customParam.setId(1);
          customParam.setName("gwf");
          CustomDto customDto = customParam.toDto();
          System.out.println(JSON.toJSONString(customDto));  // 输出 {"id":1,"name":"gwf"}

          CustomModel iModel = customDto.toModel(model -> model.setIdConcatName(model.getId()+":"+model.getName()));
          System.out.println(JSON.toJSONString(iModel)); // 输出 {"id":1,"idConcatName":"1:gwf","name":"gwf"}
      }
}