Image uploading and displaying from database H2 error spring boot thymleaf - spring-boot

Question

I am trying to build a Book shop website using Springboot,thymleaf,H2 embedded. When I try to upload the picture of new book category it gives me a null pointer error
this is my Category.class
#Entity
#Table(name="category")
public class Category implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy= GenerationType.AUTO)
#Column(name="ID")
private Long id;
#Size(min=1, max=90)
#Column(name="CATEGORY_NAME")
private String CategoryName;
#Lob
#Column(name="CATEGORY_PHOTO")
private byte[] CategoryPhoto;
public Category(Long id, #Size(min = 1, max = 90) String categoryName, byte[] categoryPhoto) {
super();
this.id = id;
CategoryName = categoryName;
CategoryPhoto = categoryPhoto;
}
public byte[] getCategoryPhoto() {
return CategoryPhoto;
}
public void setCategoryPhoto(byte[] categoryPhoto) {
CategoryPhoto = categoryPhoto;
}
public Category() {}
#OneToMany(mappedBy = "category", cascade=CascadeType.ALL, orphanRemoval=true)
private Set<Book> Books = new HashSet<>();
public Set<Book> getBooks() {
return Books;
}
CategoryController:
#Controller
#RequestMapping(value="/categories")
public class CategoryController {
private final Logger logger = LoggerFactory.getLogger(BookController.class);
private MessageSource messageSource;
#Autowired
private CategoryService categoryService;
#GetMapping
public String list(Model uiModel) {
logger.info("Listing categories:");
List<Category> categories = categoryService.findALL();
uiModel.addAttribute("categories", categories);
logger.info("No. of categories: " + categories.size());
return "categories";
}
#GetMapping(value = "/{id}")
public String show(#PathVariable Long id, Model model) {
Category category = categoryService.findbyID(id);
if(category.getCategoryPhoto() == null) {
logger.debug("Downloading photo for id: {} with size{}",
category.getId(), category.getCategoryPhoto().length);
}
model.addAttribute("category", category);
return "showCategory";
}
#GetMapping(value = "/new")
public String create(Model uiModel) {
logger.info("creating Category ...");
Category category = new Category();
uiModel.addAttribute("category", category);
return "updateCategory";
}
#PostMapping
public String saveCategory(#Valid Category category, BindingResult bindingResult,
Model uiModel, HttpServletRequest httpServletRequest, RedirectAttributes redirectAttributes,
Locale locale, #RequestParam(value="file", required=false) Part file) {
logger.info("Creating Category....");
if(bindingResult.hasErrors())
{
uiModel.addAttribute("message", new Message("error", messageSource.getMessage("category_save_fail", new Object[] {}, locale)));
uiModel.addAttribute("Category", category);
return "categories/new";
}
uiModel.asMap().clear();
redirectAttributes.addFlashAttribute("message", new Message("success", messageSource.getMessage("Category_save_success", new Object[] {}, locale)));
logger.info("Category ID" + category.getId());
//process upload file
if(file != null) {
logger.info("File name:" + file.getName());
logger.info("File size:" + file.getSize());
logger.info("File content type:" + file.getContentType());
byte[] filecontent = null;
try
{
InputStream inputStream = file.getInputStream();
if(inputStream == null)
logger.info("File InputStream is null");
filecontent = IOUtils.toByteArray(inputStream);
category.setCategoryPhoto(filecontent);
}catch(IOException ex) {
logger.error("Error Saving uploaded file");
}
category.setCategoryPhoto(filecontent);
}
categoryService.save(category);
return "redirect:/categories/" + category.getId();
}
}
updatecategories.html page :: used for creating a new category and updating category with Name and Categoryphoto
<form class="form-horizontal" th:object="${category}" th:action="#{/categories}" method="post" enctype="multipart/form-data">
<input type="hidden" th:field="*{id}"/>
<div class="form-group">
<label class="col-sm-2 control-label">Category Name</label>
<div class="col-sm-10">
<input class="form-control" th:field="*{CategoryName}"/>
</div>
</div>
<div class="form-group">
<label class="col-sm-2 control-label">Category Photo</label>
<div class="col-sm-10">
<input name="file" type="file" value="upload" class="form-control" th:field="*{CategoryPhoto}"/>
</div>
</div>
<div class="row">
<button class="btn btn-default">Save</button>
</div>
</form>
show Categories.html page for showing the category name and photo after creating or updating
<form class="form-horizontal" th:object="${category}" th:action="#{/categories}" method="post" enctype="multipart/form-data">
<input type="hidden" th:field="*{id}"/>
<div class="form-group">
<label class="col-sm-2 control-label">Category Name</label>
<div class="col-sm-10">
<input class="form-control" th:field="*{CategoryName}"/>
</div>
</div>
<div class="form-group">
<label class="col-sm-2 control-label">Category Photo</label>
<div class="col-sm-10">
<input name="file" type="file" value="upload" class="form-control" th:field="*{CategoryPhoto}"/>
</div>
</div>
<div class="row">
<button class="btn btn-default">Save</button>
</div>
</form>
here is a image when I create a new category
error Image:
sorry for Long Question description but I want to clarify the details. Help would be appreciated.

Answer 1

I got the mistake I am using MessageSource without autowiring it Done that. And Adding Messages to my properties file.