Spring mvc org.hibernate.LazyInitializationExceptio­n: could not initialize proxy - no Session

@Controller
@RequestMapping(value = "/admin")
public class AdminProductController {
 
    @Autowired
    private ProductService productService;
 
    @RequestMapping("/product")
    public String login(ModelMap model) {
        return "admin/product";
    }
 
    @RequestMapping(value = "/loadproducts", method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    public @ResponseBody List<Product> loadProducts (){
        return productService.getAll();
    }
 
    @RequestMapping(value = "/saveproduct", method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    public @ResponseBody Product saveProduct(@RequestParam Long id, @RequestParam("column") String column,
                                             @RequestParam("value") String value ) {
        Product product = productService.get(id);
        if (Objects.equals(column, "name")){
            product.setName(value);
        }else if (Objects.equals(column, "description")){
            product.setDescription(value);
        }else if (Objects.equals(column, "price")){
            product.setPrice(Double.parseDouble(value));
        }else if (Objects.equals(column, "discount")){
            product.setDiscount(Integer.parseInt(value));
        }else if (Objects.equals(column, "maxLed")){
            product.setMaxLed(Integer.parseInt(value));
        }
        return productService.save(product);
    }
 
}

@Entity
@Table(name = "products", uniqueConstraints={@UniqueConstraint(columnNames={"name"})})
public class Product  extends NamedEntity {
    @Column(name = "description")
    private String description;
 
    @Column(name = "price", nullable = false)
    private double price;
    /**
     * скидка в процентах
     */
    @Column(name = "discount")
    private int discount;
 
    /**
     * Цена со скидкой
     */
    @Column(name = "discount_price")
    private double discountPrice;
 
    /**
     * кол-во светодиодов в приборе
     */
    @Column(name = "maxLed", nullable = false)
    private int maxLed;
 
    public Product() {
    }
 
    public Product(Long id, String name, String description, double price) {
        super(id, name);
        this.description = description;
        this.price = price;
    }
 
    public Product(Long id, String name, String description, double price, int maxLed) {
        super(id, name);
        this.description = description;
        this.price = price;
        this.maxLed = maxLed;
    }
 
    public String getDescription() {
        return description;
    }
 
    public void setDescription(String description) {
        this.description = description;
    }
 
    public double getPrice() {
        return price;
    }
 
    public void setPrice(double price) {
        this.price = price;
    }
 
    public double getDiscount() {
        return discount;
    }
 
    public void setDiscount(int discount) {
        this.discount = discount;
        discountPrice = (price * discount) / 100;
    }
 
    public double getDiscountPrice() {
        return discountPrice;
    }
 
    public int getMaxLed() {
        return maxLed;
    }
 
    public void setMaxLed(int maxLed) {
        this.maxLed = maxLed;
    }
 
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        if (!super.equals(o)) return false;
 
        Product product = (Product) o;
 
        if (Double.compare(product.price, price) != 0) return false;
        return description.equals(product.description);
    }
 
    @Override
    public int hashCode() {
        int result = super.hashCode();
        long temp;
        result = 31 * result + description.hashCode();
        temp = Double.doubleToLongBits(price);
        result = 31 * result + (int) (temp ^ (temp >>> 32));
        return result;
    }
}