Bean属性“category name”不可读或具有无效的getter方法

Question

谁能看看这个错误并帮助我吗？我花了两个小时去找问题，但我没有找到解决办法。列出数据是可行的，但问题是在使用action=“saveCategory添加jsp时。

org.springframework.beans.NotReadablePropertyException：bean类[java.util.ArrayList]的属性“category name”无效：bean属性“category name”不可读或具有无效的getter方法：getter的返回类型是否与setter的参数类型匹配？

JSP：

<c:forEach var="tempInvoiceCategory" items="${invoiceCategory}">
    <tr>
        <td>${tempInvoiceCategory.categoryName}</td>
        <td>
            <button type="button" class="btn btn-info">Edit</button>
            <button type="button" class="btn btn-danger">Delete</button>
        </td>
    </tr>
</c:forEach>

<form:form class="forms-sample" action="saveCategory" modelAttribute="invoiceCategory" method="POST">
    <div class="form-group">
        <label>Nazwa Kategorii</label>
        <form:input path="categoryName" type="text" class="form-control"/>
    </div>
    <button type="submit" class="btn btn-primary mr-2">Submit</button>
</form:form>

实体：

@Entity
@Table(name="T_INVOICE_CATEGORY")
public class InvoiceCategory {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="ID_CATEGORY")
    private int id;
    
    @Column(name="CATEGORY_NAME")
    private String categoryName;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getCategoryName() {
        return categoryName;
    }

    public void setCategoryName(String categoryName) {
        this.categoryName = categoryName;
    }

    @Override
    public String toString() {
        return "InvoiceCategory [id=" + id + ", categoryName=" + categoryName + "]";
    }
    
}

控制器：

@Controller
@RequestMapping("/invoice")
public class InvoiceController {
    
    @Autowired
    private InvoiceCategoryService invoiceCategoryService;
    
    @GetMapping("/listCategory")
    public String listCategory(Model theModel) {
        
        List<InvoiceCategory> invoiceCategory = invoiceCategoryService.getInvoiceCategory();
        
        theModel.addAttribute("invoiceCategory",invoiceCategory);
        
        return "add-invoice-category";
    }
        
    @PostMapping("/saveCategory")
    public String saveCustomer(@ModelAttribute("invoiceCategory") InvoiceCategory theInvoiceCategory) {
        invoiceCategoryService.saveInvoiceCategory(theInvoiceCategory);
        
        return "redirect:/customer/list";
    }
}

Answer 1

我认为问题是模型属性InvoiceCategory是list 并且在同一个JSP中尝试构建项目列表和尝试访问该项目的表单，但它是list :

<form:form class="forms-sample" action="saveCategory" modelAttribute="invoiceCategory" method="POST">
    <div class="form-group">
        <label>Nazwa Kategorii</label>
        <form:input path="categoryName" type="text" class="form-control"/>
    </div>
    <button type="submit" class="btn btn-primary mr-2">Submit</button>
</form:form>

请尝试注释此部分并再次运行应用程序。