java - transient 属性值异常 : object references an unsaved transient instance - save the transient instance before flushing

Question

我正在尝试将用户详细信息存储到下表中:user、role、user_role。尝试保存详细信息时，它会引发以下错误。

Error during managed flush [org.hibernate.TransientPropertyValueException: object references an unsaved transient instance - save the transient instance before flushing

这里user_role是父表，user和role表是子表。我尝试使用 cascade = CASCADE.ALL。即使它抛出了同样的错误。

用户.java

@Entity
public class User implements UserDetails, Serializable{

    private static final long serialVersionUID = 902783495L;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="Id", nullable=false, updatable = false)
    private Long id;

    private String username;
    private String password;
        private String email;

    private boolean enabled = true;

    @OneToMany(mappedBy = "user", cascade=CascadeType.ALL, fetch = FetchType.EAGER)
    @JsonIgnore
    private Set<UserRole> userRoles = new HashSet<>();

    public Long getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }



    public void setEnabled(boolean enabled) {
        this.enabled = enabled;
    }

    public Set<UserRole> getUserRoles() {
        return userRoles;
    }

    public void setUserRoles(Set<UserRole> userRoles) {
        this.userRoles = userRoles;
    }

        public String getEmail() {
        return email;
    }

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

    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {

        Set<GrantedAuthority> authorities = new HashSet<>();
        userRoles.forEach(ur -> authorities.add(new Authority(ur.getRole().getName())));

        return authorities;
    }

    @Override
    public boolean isAccountNonExpired() {
        // TODO Auto-generated method stub
        return true;
    }

    @Override
    public boolean isAccountNonLocked() {
        // TODO Auto-generated method stub
        return true;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        // TODO Auto-generated method stub
        return true;
    }

    @Override
    public boolean isEnabled() {
        return enabled;
    }




}

角色.java

@Entity
public class Role implements Serializable{

    private static final long serialVersionUID = 890245234L;

    @Id
    private int roleId;

    private String name;

    @OneToMany(mappedBy = "role", cascade=CascadeType.ALL, fetch = FetchType.LAZY)
    private Set<UserRole> userRoles = new HashSet<>();

    public Role(){}

    public int getRoleId() {
        return roleId;
    }

    public void setRoleId(int roleId) {
        this.roleId = roleId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Set<UserRole> getUserRoles() {
        return userRoles;
    }

    public void setUserRoles(Set<UserRole> userRoles) {
        this.userRoles = userRoles;
    }


}

用户角色.java

@Entity
@Table(name="user_role")
public class UserRole implements Serializable {
    private static final long serialVersionUID = 890345L;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long userRoleId;

    public UserRole () {}

    public UserRole (User user, Role role) {
        this.user = user;
        this.role = role;
    }

    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "user_id")
    private User user;

    @ManyToOne(fetch = FetchType.EAGER)
    private Role role;

    public long getUserRoleId() {
        return userRoleId;
    }

    public void setUserRoleId(long userRoleId) {
        this.userRoleId = userRoleId;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public Role getRole() {
        return role;
    }

    public void setRole(Role role) {
        this.role = role;
    }


}

Answer 1

这里 role_id 是主键，你每次都试图将 1 设置为 role_id，用 @ID @GeneratedValue(策略= GenerationType.AUTO) 私有(private)长序列号；