java - Hibernate saveOrUpdate 不会更新现有记录，而是将记录另存为新条目

Question

从今天早上开始就一直在寻找这个问题，但我找不到这个问题的正确答案，我正在使用 ID 作为引用来更新记录，但不是更新应用程序而是插入现有的新条目记录，控制台显示“插入”而不是“更新”。以下是该应用程序的片段:

Controller :

@PostMapping("/saveCustomer")
public String saveCustomer(@ModelAttribute("customer") Customer customer) {

    customerService.saveCustomer(customer);

    return "redirect:/erp/list";
}

@GetMapping("/showFormForUpdate")
public String showFormForUpdate(@RequestParam("customerId") int id, Model model) {

    Customer customer = customerService.getCustomer(id);

    model.addAttribute("customer", customer);

    return "customer-form";
}

DAO 实现:

@Override
public void saveCustomer(Customer customer) {
    Session currentSession = sessionFactory.getCurrentSession();

    currentSession.saveOrUpdate(customer);
}

实体:

@Entity
@Table(name="customer")
public class Customer {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="id")
private int id;

@Column(name="company_name")
private String companyName;

@Column(name="company_email")
private String companyEmail;

@Column(name="company_address")
private String companyAddress;

@Column(name="contact_no")
private String contactNo;

@Column(name="company_tin")
private String companyTin;

public Customer() {

}

public String getContactNo() {
    return contactNo;
}

public void setContactNo(String contactNo) {
    this.contactNo = contactNo;
}

public String getCompanyName() {
    return companyName;
}

public void setCompanyName(String companyName) {
    this.companyName = companyName;
}

public String getCompanyEmail() {
    return companyEmail;
}

public void setCompanyEmail(String companyEmail) {
    this.companyEmail = companyEmail;
}

public String getCompanyAddress() {
    return companyAddress;
}

public void setCompanyAddress(String companyAddress) {
    this.companyAddress = companyAddress;
}

public String getCompanyTin() {
    return companyTin;
}

public void setCompanyTin(String companyTin) {
    this.companyTin = companyTin;
}

public int getId() {
    return id;
}

Answer 1

我认为您的 bean 中缺少 setter 方法:

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

这就是为什么当您添加模型属性时，它不会在您的 bean 中设置 id 值。