Question

我有其余的模型用于构建发送的JSON。

休息模式

@Getter @Setter
@ToString
public class OrderRequestModel {
    private String orderKeyId;
    private String paymentMode;
    private double totalAmount;
    private List<ProductRequestModel> orderProducts;
    private UserDetailsRequestModel seller;
    private Date createdAt;
}

ProductRequestModel相似

@Getter @Setter
@ToString
public class ProductRequestModel {
    private String productKeyId;
    private String name;
    private double price;
    private int qty;
    private String imgPath;

    private CategoryRequestModel category;
}

我将模型传递给与数据库有关的DTO层（它们包含一个长ID）：

@Getter @Setter
@ToString
public class OrderDto implements Serializable {
    @Getter(AccessLevel.NONE)
    @Setter(AccessLevel.NONE)
    private static final long serialVersionUID = 1L;

    private Long id;
    private String orderKeyId;
    private String paymentMode;
    private double totalAmount;
    private List<ProductDto> orderProducts;
    private UserDto seller;
    private Date createdAt;
}

和我的ProductDto：

@Getter @Setter
@ToString
public class ProductDto implements Serializable {
    // ommit this member and do not generate getter / setter
    @Getter(AccessLevel.NONE)
    @Setter(AccessLevel.NONE)
    private static final long serialVersionUID = 1L;

    private Long id;
    private String productKeyId;
    private String name;
    private double price;
    private int qty;
    private String imgPath;

    private CategoryDto category = new CategoryDto();
}

当我尝试将OrderDto映射到关联的模型时，我会隐式地进行操作：

OrderDto orderDto = modelMapper.map(orderRequestModel, OrderDto.class);

理论上，模型中的orderKeyId应该与其Dto中的等效项匹配。不幸地，它返回一个错误：

Converter org.modelmapper.internal.converter.NumberConverter@3e36f4cc failed to convert java.lang.String to java.lang.Long.
Caused by: org.modelmapper.MappingException: ModelMapper mapping errors:

我确实需要DTO中的ID，因为如果要进行更新，请使用“ id”

Answer 1

此问题是由于映射策略引起的。我们可以将映射策略设置为STRICT，以便从源对象属性映射到目标对象属性时，仅映射那些在属性名称及其数据类型上完全匹配的属性。下面是一个示例。

public ModelMapper modelMapper() {
    ModelMapper modelMapper = new ModelMapper();
    modelMapper.getConfiguration()
        .setMatchingStrategy(MatchingStrategies.STRICT);
}

仅供参考： http://modelmapper.org/user-manual/configuration/#matching-strategies

ModelMapper无法将java.lang.String转换为java.lang.Long

1 个答案: