java.lang.IllegalStateException : org. hibernate.TransientObjectException(更新记录时)

Question

在使用 hibernate 更新记录时，我不断收到以下异常，我对 hibernate 非常陌生，请查看该异常跟踪

java.lang.IllegalStateException: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.rasvek.cms.entity.Country
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:146)
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:157)
    ...
Caused by: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.rasvek.cms.entity.Country
    at org.hibernate.engine.internal.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:279)
    at org.hibernate.type.EntityType.getIdentifier(EntityType.java:493)
    at org.hibernate.type.EntityType.nullSafeSet(EntityType.java:280)
    ...

请看我的实体类:

@Entity
@Table(name = "state", catalog = "cms_db")
public class State implements java.io.Serializable {

    private Integer stateId;
    private Country country;
    private String stateName;
    private String status;  
    private Set<District> districts = new HashSet<District>(0);

    public State() { 
    public State(Country country) {
        this.country = country;
    }

    public State(Country country, String stateName, String status, Set<District> districts) {
        this.country = country;
        this.stateName = stateName;
        this.status = status;
        this.districts = districts;
    }

    @Id
    @GeneratedValue(strategy = IDENTITY)

    @Column(name = "state_id", unique = true, nullable = false)
    public Integer getStateId() {
        return this.stateId;
    }

    public void setStateId(Integer stateId) {
        this.stateId = stateId;
    }

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "country_id", nullable = false)
    public Country getCountry() {
        return this.country;
    }

    public void setCountry(Country country) {
        this.country = country;
    }

    @Column(name = "state_name")
    public String getStateName() {
        return this.stateName;
    }

    public void setStateName(String stateName) {
        this.stateName = stateName;
    }

    @Column(name = "status")
    public String getStatus() {
        return this.status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "state")
    public Set<District> getDistricts() {
        return this.districts;
    } 

    public void setDistricts(Set<District> districts) {   
        this.districts = districts;
    }
}

Controller 及其方法

@RestController
@RequestMapping(value="/master")
public class MasterController {

    @PutMapping("/updateState")
    public ResponseEntity<Map<String, Object>> updateState(@RequestBody State theState) {
        ResponseEntity<Map<String, Object>> responseEntity = null;
        try {  
            boolean res = service.updateState(theState) ;        
            if (res) {
                headers.add("head", "State");
                message.put("status", true);
                message.put("data", "State has been updated successfully!");
                responseEntity = new ResponseEntity<Map<String, Object>>
                    (message, headers, HttpStatus.CREATED);

            } else {
                headers.add("head", "null");
                message.put("status", false);
                message.put("errorMessage", "State has not been updated successfully!");
                responseEntity= new ResponseEntity<Map<String, Object>>
                    (message, headers, HttpStatus.NOT_FOUND);
                }
            } catch (Exception e) { }
            return responseEntity;
        }
}

DAO:

public boolean updateState(State theState) {
    boolean success = false;
    try {
        currentSession=sessionFactory.getCurrentSession();
        currentSession.saveOrUpdate(theState);
        success=true;
    } catch (Exception e) { }
    return success;
}

Answer 1

您可以使用级联。

@ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)

CascadeType.ALL 是持久性会将所有 EntityManager 操作(PERSIST、REMOVE、REFRESH、MERGE、DETACH)传播到相关实体。

另一种方式

public boolean updateState(State theState) {
    boolean success = false;
    try {
        currentSession=sessionFactory.getCurrentSession();
        currentSession.saveOrUpdate(theState.getCountry());
        currentSession.saveOrUpdate(theState);
        success=true;
    } catch (Exception e) { }
    return success;
}