Getting file with model field in spring mvc - spring-mvc

Question

I am try to upaload a file with some other fields for model, but I can't binding file with those fields.
handling request.
#RequestMapping(value="/products", method=RequestMethod.POST)
public String saveProduct(#Valid #ModelAttribute("product") Product product, BindingResult result){
if (result.hasErrors()) {
return "manageProduct";
}
}
in model class with some other fields
#Entity
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
private String code;
#NotBlank(message = "Product name can't be blank")
private String name;
#NotBlank(message = "Brand name can't be blank")
private String brand;
#NotBlank(message = "Description can't be blank.")
#Size(min = 10, max = 500, message = "Description shoud be contain 10 and 500 characters")
#JsonIgnore
private String description;
#Min(value = 1)
#Column(name = "unit_price")
private float unitPrice;
private int quantity;
#JsonIgnore
#Column(name = "is_active")
#OrderBy("id ASC")
private boolean active;
#Column(name = "category_id")
#JsonIgnore
private int categoryId;
#Column(name = "supplier_id")
#JsonIgnore
private int supplierId;
private int purchases = 0;
private int views = 0;
#Transient
private MultipartFile file;
//getters and setters
}
form also enctype="multipart/form-data" and method is "post".
When try to upload file with others fields, then errors occurs.
And I am using spring boot.

Answer 1

Assuming you are using Spring Data and JPA then Spring Content provides a solution to uploading and associating content with your entity.
As you are using Spring Boot it is easy to add. Add the following dependencies:
pom.xml
<!-- Java API -->
<dependency>
<groupId>com.github.paulcwarren</groupId>
<artifactId>spring-content-jpa-boot-starter</artifactId>
<version>0.0.11</version> <!-- Or 0.1.0 for Spring Boot 2 -->
</dependency>
<!-- REST API -->
<dependency>
<groupId>com.github.paulcwarren</groupId>
<artifactId>spring-content-rest-boot-starter</artifactId>
<version>0.0.11</version> <!-- Or 0.1.0 for Spring Boot 2 -->
</dependency>
Add the following attributes to your Product entity so that content can be associated with it (this is in place of your Multipart file field):
Product.java
#Entity
public class Product {
...existing fields...
#ContentId
private String contentId;
#ContentLength
private long contentLength = 0L;
#MimeType
private String mimeType;
// no need for MultipartFile
Create a ContentStore (the equivalent of a JpaRepository for BLOBs):
ProductContentStore.java
#StoreRestResource(path="productsContent")
public interface ProductContentStore extends ContentStore<Product, String> {
}
When you run your application Spring Content will see the ProductContentStore interface and the spring-content-jpa dependency and inject an JPA implementation of this interface for you meaning that you don't have to write this yourself. It will also see the spring-content-rest dependency and add an #Controller implementation that forwards GET, PUT, POST and DELETE REST requests onto the ProductContentStore bean meaning that you don't have to write this controller either. REST endpoints will be available at /productsContent so...
after creating your product and getting an ID, you can then:
curl -X POST -F "image=#/some/local/path/product.jpg" /productsContent/{productId}
to upload product.jpg and associate it with your product entity. And:
curl /productsContent/{productId} will fetch it again.
Yes, this does imply that you need TWO requests to create a product and associate an image with it. If you have valid reasons that justify why this needs to be one request and not two then raise an issue against Spring Content github repo and we can look into adding support this for you.
HTH