【发布时间】：2020-09-10 22:11:32
【问题描述】：
我正在创建一对多关系，其中类别有许多产品。在列出我现有的所有类别后，我想查看特定类别中的所有产品并对这些产品（来自该类别）进行基本的 CRUD。 我发现在 Thymeleaf 中重定向页面有困难，最确切地说，我无法使用 Thymeleaf 访问“添加产品”页面。
@Entity
@Table(name="category")
public class Category {
@Id
@GeneratedValue(strategy= GenerationType.IDENTITY)
@Column(name="id")
private long id;
@Column
@NotEmpty(message = "*Please provide a description")
private String description;
@OneToMany(mappedBy = "category")
private Set<Product> products;
public Category(){}
@Entity
@Table(name="product")
public class Product {
@Id
@Column(name="id")
private String id;
@Column
private String name;
@Column
private String description;
@Column
private float price;
@Column
private int discount;
@Column
private boolean isInStock;
@ManyToOne
@JoinColumn(name="category_id")
private Category category;
这是我在服务层保存产品的方式
public Product save(Product product, long id) {
Category category = categoryRepository.getById(id);
if (category != null) {
product.setId(UUID.randomUUID().toString());
product.setCategory(category);
product.setInStock(false);
return productRepository.save(product);
} else {
throw new ResourceNotFoundException("Category not found with id: " + id);
}
}
在控制器中我有：
@Autowired
ProductService productService;
@GetMapping("/products/{categoryId}")
public String viewProducts(Model model, @PathVariable("categoryId") long categoryId) {
List<Product> productsList = productService.findByCategoryId(categoryId);
model.addAttribute("productsList", productsList);
model.addAttribute("categoryId",categoryId );
return "products";
}
@GetMapping("/newProduct/{categoryId}")
public String showAddForm(Model model,@PathVariable("categoryId") long categoryId) {
Product product = new Product();
model.addAttribute("product", product);
return "newProduct";
}
@PostMapping("/save/{categoryId}")
public String addProduct(@ModelAttribute("product") Product product, @PathVariable long categoryId){
productService.save(product, categoryId);
return "redirect:products";
}
我卡住的地方是我无法使用路径变量 categoryId 从 products.html 重定向到 newProduct.html（showAddForm 方法应该返回）。如果我手动输入 categoryId，它会将我重定向到错误页面在 URL 中，我终于找到了 newProduct.html。在 products.html 中，我有：
<body>
<div class="container my-2">
<div class="card">
<div class="card-body">
<!-- TODO get category ID from categories (parameters between HTML)-->
<div th:switch="${productsList}" class="container my-5">
<p class="my-5">
<a href="/product/newProduct/" class="btn btn-primary">Add product</a>
</p>
<div class="col-md-10">
<h2 th:case="null">No Products yet!</h2>
<div th:case="*">
<table class="table table-striped table-responsive-md">
<thead>
<tr>
<th>Name</th>
<th>Description</th>
<th>Price</th>
<th>Discount</th>
<th>IsInStock</th>
<th>Edit</th>
<th>Delete</th>
</tr>
</thead>
<tbody>
<tr th:each="product : ${productsList}">
<td th:text="${product.name}"></td>
<td th:text="${product.description}"></td>
<td th:text="${product.discount}"></td>
<td th:text="${product.price}"></td>
<td th:text="${product.isInStock}"></td>
<td><a th:href="@{/product/edit/{id}(id=${product.id})}" class="btn btn-primary"></a></td>
<td><a th:href="@{/product/delete/{id}(id=${product.id})}" class="btn btn-primary"></a></td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
【问题讨论】：
标签： java spring-boot jpa thymeleaf one-to-many