带有 MySQL 名称的 Thymeleaf 循环答案

【问题标题】：Thymeleaf loop with names from MySQL带有 MySQL 名称的 Thymeleaf 循环
【发布时间】：2017-09-12 05:57:01
【问题描述】：

试图从数据库中获取名称以显示在网页上，但得到一个空白页面。让我知道我做错了什么，应用确实可以工作，所以没有值得发布的堆栈跟踪

简单的 Thymeleaf 视图：

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org" xmlns:text="http://www.w3.org/1999/xhtml">
<head lang="en"></head>
<body th:each="customer: ${customers}">
<h2 th:text="${customer}"></h2>
</body>
</html>

控制器：

@Controller
public class CustomerController {

    @Autowired
    private CustomerDAO customerDAO;

    @RequestMapping("/list")
    public String listCustomers(Model model){
     List<Customer> customers = customerDAO.findAll();
     model.addAttribute("customers", customers);
    return "list-customers";
    }
}

道：

@Repository
@Transactional
public interface CustomerDAO extends CrudRepository<Customer, String> {
    public List<Customer> findAll();

}

实施：

@Transactional
@Repository
public abstract class CustomerDAOImpl implements CustomerDAO {

    private SessionFactory sessionFactory;

    private CustomerDAO customerDAO;

    @Override
    public List<Customer> findAll() {
       return customerDAO.findAll();
        }   
}

实体：

@Entity
@Table(name = "customer")
public class Customer implements Serializable {

    @Column(name = "id")
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

    @Column(name = "first_name")
    private String firstName;

    @Column(name = "last_name")
    private String lastName;

    @Column(name = "email")
    private String email;

    public Customer(){}

    public Customer(String firstName, String lastName, String company){
        this.firstName = firstName;
        this.lastName = lastName;
        this.email = company;
    }

    @Override
    public String toString() {
        return "Customer{" +
                "id=" + id +
                ", firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", email='" + email + '\'' +
                '}';
    }

    public int getId() {
        return id;
    }

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

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getCompany() {
        return email;
    }

    public void setCompany(String company) {
        this.email = company;
    }
}

【问题讨论】：

使用<body th:each="customer: ${customers}">您可以在一个 HTML 中创建多个正文标签。这在 HTML 中是不允许的。保持身体标签清洁并使用例如一个额外的 div 标签。

标签： mysql hibernate spring-boot thymeleaf

【解决方案1】：

您的 HTML 应更新为：

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org" xmlns:text="http://www.w3.org/1999/xhtml">
<head lang="en"></head>
<body>
  <div th:each="customer: ${customers}">
    <h2 th:text="${customer}"></h2>
  </div>
</body>
</html>

这将对您的每个 customer 对象调用 toString() 方法。

如果您仍然看到一个空列表，您可以在查询调用中添加断点并运行调试器，或者简单地记录计数/元素以查看您的存储库/数据库返回的内容。

【讨论】：