[英]Hibernate saveorupdate or merge for saving/updating one-to-many relationship objects
我正在使用Spring MVC 3和Hibernate開發應用程序。 我有2個具有父子關系的User和TenancyDetails類。 在編輯詳細信息功能中,我們可以編輯User類的詳細信息,並動態添加classTenancyDetails項目並保存更改。 我為此使用hibernate saveorupdate()方法,並且hibernate應該在更新現有記錄時為User類創建一條新記錄。 這是我的代碼。
模型類別:
@Entity
@Table(name="tenancydetails")
public class TenancyDetails {
@Column(name="tenancyID")
@Id
@GeneratedValue
private int tenancyId;
@Column(name="landlordName")
@NotNull
private String landlordName;
@Column(name="landLordEmail")
@NotNull
private String landlordEmail;
@Column(name="fromDate")
@NotNull
private Date fromDate;
@Column(name="toDate")
@NotNull
private Date toDate;
@Column(name="location")
@NotNull
private String location;
@ManyToOne(cascade=CascadeType.ALL)
@JoinColumn(name="userId", nullable=false)
private User user;
@Transient
protected Object[] jdoDetachedState;
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public int getTenancyId() {
return tenancyId;
}
public void setTenancyId(int tenancyId) {
this.tenancyId = tenancyId;
}
public String getLandlordName() {
return landlordName;
}
public void setLandlordName(String landlordName) {
this.landlordName = landlordName;
}
public String getLandlordEmail() {
return landlordEmail;
}
public void setLandlordEmail(String landlordEmail) {
this.landlordEmail = landlordEmail;
}
public Date getFromDate() {
return fromDate;
}
public void setFromDate(Date fromDate) {
this.fromDate = fromDate;
}
public Date getToDate() {
return toDate;
}
public void setToDate(Date toDate) {
this.toDate = toDate;
}
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
}
@Entity
@Table(name="User")
public class User {
@Column(name="userId")
@Id
private int userId;
@Column(name="name")
private String name;
@Column(name="emailId")
@NotEmpty(message = "Please enter your email id")
@Size(max = 50, message = "Email id can only be upto 50 characters long")
private String emailId;
@Column(name="password")
@NotEmpty(message = "Please enter your password")
@Size(max = 20, message = "Password can only be upto 20 characters long")
private String password;
@OneToMany(cascade={CascadeType.ALL}, fetch = FetchType.EAGER)
@Cascade({org.hibernate.annotations.CascadeType.DELETE_ORPHAN,
org.hibernate.annotations.CascadeType.PERSIST,
org.hibernate.annotations.CascadeType.SAVE_UPDATE})
@JoinColumn(name="userId"/*, nullable=true*/)
@LazyCollection(LazyCollectionOption.FALSE)
private List<TenancyDetails> tenancyDetails = null;
public User(){
tenancyDetails = new AutoPopulatingList<TenancyDetails>(TenancyDetails.class);
}
public List<TenancyDetails> getTenancyDetails() {
return tenancyDetails;
}
public void addTenancyDetail(TenancyDetails tenancyDetail) {
if (!tenancyDetails.contains(tenancyDetail)) {
tenancyDetails.add(tenancyDetail);
}
}
public void setTenancyDetails(List<TenancyDetails> tenancyDetails) {
this.tenancyDetails = tenancyDetails;
}
public int getUserId() {
return userId;
}
public void setUserId(int userId) {
this.userId = userId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmailId() {
return emailId;
}
public void setEmailId(String emailId) {
this.emailId = emailId;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
控制器:
@RequestMapping(value = "/Profile/{userId}", method = RequestMethod.POST)
public ModelAndView saveProfileDetails(@PathVariable int userId, Model model, HttpServletRequest request, HttpServletResponse response,
HttpSession session, ModelMap modelMap, @ModelAttribute("user") User user) {
System.out.println("am in save");
model.addAttribute("user", user);
System.out.println(user.getPassword());
System.out.println(user.getTenancyDetails().get(0).getUser().getUserId());
System.out.println(model.containsAttribute("user"));
tenantRatingService.saveProfileDetails(user);
return new ModelAndView("editProfile","user", user);
}
DAO方法:
public void saveProfileDetails(User user){
System.out.println("inside the save profile method");
Session session = getSession();
Transaction transaction = session.beginTransaction();
System.out.println("before save: " + user.getPassword());
System.out.println("before save: " + user.getTenancyDetails().get(0).getUser().getUserId());
session.saveOrUpdate(user);
transaction.commit();
session.flush();
System.out.println(user.getPassword());
}
我也將這兩個類的id字段設置為mysql中的AUTO_INCREMENT字段。 我使用的一對多映射或@GeneratedValue是否存在問題? 還是與saveorupdate()方法有關? 在這種情況下,我應該使用merge()嗎? 在saveorupdate()語句之前,已正確打印出現有userId的值!
有人可以讓我知道我要去哪里嗎? 提前致謝。
我不知道,您如何在呈現表單時將user
對象放入Model
而表單最終出現在您的POST方法"/Profile/{userId}"
。 user
對象的id
變為0
。 這就是為什么saveOrUpdate
方法再次保存您的user
的原因。 要進行驗證,可以在進入saveProfileDetails
方法之前添加以下行:
user.setUserId(userId);
您的問題將得到解決。
您還可以通過將@SessionAttributes("user")
放在"/Profile/{userId}"
的GET
和POST
方法的所有者控制器之前,來解決此問題。
也可以看看:
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