Issue mapping fields ModelMapper - spring

Question

I use DTO and modelMapper in order not to make visible some fields.
I have a CategoryEntity that can have subcategories
public class CategoryEntity {
#Id
#GeneratedValue(strategy= GenerationType.IDENTITY)
private Long id;
#Column(length = 30, nullable = false)
private String categoryKeyId;
#Column(nullable = false)
private String name;
#ManyToOne(optional = true, fetch = FetchType.LAZY)
#JoinColumn(name="parent_id", nullable=true)
private CategoryEntity parentCategory;
// allow to delete also subcategories
#OneToMany(mappedBy="parentCategory", cascade = CascadeType.ALL)
private List<CategoryEntity> subCategories;
}
When i create a category I use a model:
#Getter #Setter
public class CategoryRequestModel {
private String name;
private String parentCategoryKeyId;
}
In this model i want parentCategoryKeyId to match with the categoryKeyId of the parent.
For example if i create a "top" category :
{
"name": "topCategory"
}
It returns me :
{
"categoryKeyId": "jUcpO27Ch2YrT2zkLr488Q435F8AKS",
"name": "topCategory",
"subCategories": null
}
When i do this :
{
"name": "sub",
"parentCategoryKeyId": "jUcpO27Ch2YrT2zkLr488Q435F8AKS"
}
In my Controller, i pass the rest object to a DTO Layer which calls a service :
public CategoryRestResponseModel createCategory(#RequestBody CategoryRequestModel categoryRequestModel) {
CategoryRestResponseModel returnValue = new CategoryRestResponseModel();
if( categoryRequestModel.getName().isEmpty())
throw new NullPointerException(ErrorMessages.MISSING_REQUIRED_FIELDS.getErrorMessage());
ModelMapper modelMapper = new ModelMapper();
CategoryDto categoryDto = modelMapper.map(categoryRequestModel, CategoryDto.class);
CategoryDto createdCategory = categoryService.createCategory(categoryDto);
returnValue = modelMapper.map(createdCategory, CategoryRestResponseModel.class);
return returnValue;
}
My CategoryDto is a basic POJO :
#Getter #Setter
public class CategoryDto implements Serializable {
#Getter(AccessLevel.NONE)
private static final long serialVersionUID = 1L;
private String categoryKeyId;
private String parentCategoryKeyId;
private String name;
private CategoryDto parentCategory;
private List<CategoryDto> subCategories;
}
In my Service :
public CategoryDto createCategory(CategoryDto categoryDto) {
//1. Create an empty object to return
System.out.println("Hello World");
CategoryDto returnValue = new CategoryDto();
System.out.println("CategoryDto: " + categoryDto);
// check if category exists
if (categoryRepository.findByName(categoryDto.getName()) != null)
throw new ApplicationServiceException("Record already in Database");
ModelMapper modelMapper = new ModelMapper();
CategoryEntity categoryEntity = modelMapper.map(categoryDto, CategoryEntity.class);
// Generate categoryKeyId
String categoryKeyId = utils.generateCategoryKeyId(30);
categoryEntity.setCategoryKeyId(categoryKeyId);
System.out.println("categoryDto parentCategory: " + categoryDto.getParentCategory());
System.out.println("CategoryDto: " + categoryDto);
if(categoryDto.getParentCategoryKeyId() != null) {
CategoryEntity parentCategory = categoryRepository.findByCategoryKeyId(categoryDto.getParentCategoryKeyId());
categoryEntity.setParentCategory(parentCategory);
System.out.println("CategoryEntity: " + categoryEntity);
System.out.println("parentCategory: " + parentCategory);
}
CategoryEntity storedCategory = categoryRepository.save(categoryEntity);
returnValue = modelMapper.map(storedCategory, CategoryDto.class);
return returnValue;
}
My issue is that I would like to save the subcategory and retrieve the ID that match the categoryKeyId ...
In the database my entry should be like this
My First entry should have:
id = 1 - parent_id = null, category_key_id = jUcpO27Ch2YrT2zkLr488Q435F8AKS, name = topCategory ...
AND :
id = 2 - parent_id = 1 , category_key_id = "another generated key", name= sub
Unfortunatelly I just persist the id, the categorykeyid and the name.
I removed id from CategoryDto and i obtain : 1) Converter org.modelmapper.internal.converter.NumberConverter#348fc3d8 failed to convert java.lang.String to java.lang.Long.

Answer 1

I solved it in a "dirty" way.
I just changed my object in entry and added a long id.
It gives me :
#Getter #Setter
public class CategoryRequestModel {
private Long id;
private String name;
private String parentCategoryKeyId;
}