问题：
EclipseLink返回主键为空的实体
游安康
我有一个我觉得很神秘的问题。我在Google和StackOverflow上搜索过，没有发现任何人有类似的问题。我尝试将持久化提供程序切换到Hibernate，但我们的代码过于依赖EclipseLink特性，因此无法将其作为调试的实际选项。如果这个问题仍然存在（哈，哈；Java EE双关语），我很可能会为Hibernate重写所有持久性代码，如果可能的话。
- 我的一个实体
ExperientBlock被正确持久化到数据库，并且它的自动增量主键被正确生成。但是，当它从数据库中读取时，EclipseLink会给出一个主键字段为空的实体。这在生产软件中造成了毁灭性的bug。 ExperientBlock从其超类PeriodreSident继承主键字段并带有注释、一个getter和一个setter。periodresident的其他几个子类也这样做，但是EclipseLink正确地加载了它们的主键。这就是这个bug的奥秘所在:periodresident的每个子类都使用完全相同的field/getter/setter代码，但是experientblock是EclipseLink返回的唯一主键为空的子类！- 运行一个选择
ExpermentBlocks的JPQL查询会返回主键为null的查询。（愁容满面。）但是，运行一个专门选择ExperientBlock的主键字段的JPQL查询可以正常工作，并返回一个整数主键列表！这可以在下面的查询experientblock.findWithIDSBySchedule中看到。
GlassFish 3.1.2,EclipseLink 2.4.0,Java EE 6,MySQL 5.0.95-log
我没有任何例外。此问题发生在远程和本地会话bean中。
代码如下，请让我知道如果我应该提供任何更多的细节。
package ohno;
import ohno.ShiftDateConverter;
import ohno.Shift;
import ohno.Facility;
import java.io.Serializable;
import java.util.Date;
import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.DiscriminatorColumn;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
import org.eclipse.persistence.annotations.Convert;
import org.eclipse.persistence.annotations.Converter;
@Converter(converterClass=ShiftDateConverter.class, name="ShiftDateConverter")
@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name="bs_blocks")
@DiscriminatorColumn(name="block_type")
public abstract class PeriodResident implements Serializable {
private static final long serialVersionUID = 1L;
public PeriodResident() {
}
/**
* Sets the database unique id.
*
* @param uniqueID the new database unique id
*/
public void setUniqueID(Integer uniqueID) {
this.uniqueID = uniqueID;
}
/**
* Provides a useful super-constructor handling initialization of the first
* and last Shifts of the PeriodResident's time block, and the Facility
* where it takes place.
*
* @param startShift The first Shift in the PeriodResident's time block.
* @param endShift The last Shift in the PeriodResident's time block.
* @param facility The Facility where the PeriodResident takes place.
* @param uniqueID the unique id
*/
public PeriodResident(Shift startShift, Shift endShift, Facility facility,
int uniqueID) {
this.startShift = startShift;
this.endShift = endShift;
this.facility = facility;
this.uniqueID = uniqueID;
}
/**
* Instantiates a new period resident.
*
* @param startShift The first Shift in the PeriodResident's time block.
* @param endShift The last Shift in the PeriodResident's time block.
* @param facility The Facility where the PeriodResident takes place.
*/
public PeriodResident(Shift startShift, Shift endShift, Facility facility) {
this(startShift, endShift, facility, null);
}
/**
* Gets the facility.
*
* @return the Facility where the PeriodResident takes place.
*
* @see #setFacility(Facility)
*/
public Facility getFacility() {
return facility;
}
/**
* Gets the shifts.
*
* @return the total number of Shifts in the PeriodResident's time block.
*
* @see #getStartShift()
* @see #getEndShift()
*/
public int getShifts() {
return endShift.getShiftsDifference(startShift);
}
/**
* Gets the start shift.
*
* @return the first <code>Shift</code> in the PeriodResident's time
* block.
*
* @see #setStartShift(Shift)
* @see #getShifts()
*/
public Shift getStartShift(){
return startShift;
}
/**
* Gets the end shift.
*
* @return the last <code>Shift</code> in the PeriodResident's time block.
*
* @see #setEndShift(Shift)
* @see #getShifts()
*/
public Shift getEndShift(){
return endShift;
}
/**
* Gets the database table unique ID for this particular PeriodResident, or null if
* it hasn't one.
*
* @return this PeriodResident's unique ID in the database.
*/
public Integer getUniqueID() {
return uniqueID;
}
/**
* sets this PeriodResident's facility location with the given Facility.
*
* @param facility the PeriodResident's new Facility.
*
* @see #getFacility()
*/
public void setFacility(Facility facility) {
this.facility = facility;
}
/**
* sets this PeriodResident's time block's new starting shift with the given
* Shift.
*
* @param startShift the new starting shift.
*
* @see #getStartShift()
*/
public void setStartShift(Shift startShift) {
this.startShift = startShift;
}
/**
* sets this PeriodResident's time block's new ending shift with the given
* Shift.
*
* @param endShift the new ending shift.
*
* @see #getEndShift()
*/
public void setEndShift(Shift endShift) {
this.endShift = endShift;
}
public Schedule getSchedule() {
return schedule;
}
public void setSchedule(Schedule schedule) {
this.schedule = schedule;
}
protected void copyCharacteristics(PeriodResident original, PeriodResident clone) {
clone.setStartShift(original.getStartShift().clone());
clone.setEndShift(original.getEndShift().clone());
clone.setFacility(original.getFacility());
clone.setSchedule(original.getSchedule());
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "PeriodResident (Facility: " + facility + ") from " + startShift + " to " + endShift;
}
@Override
public abstract Object clone();
public abstract String getResidentType();
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final PeriodResident other = (PeriodResident) obj;
if ((uniqueID == null && other.uniqueID != null) || (this.uniqueID != null && !this.uniqueID.equals(other.uniqueID))) {
return false;
}
return true;
}
@Override
public int hashCode() {
if (uniqueID != null) {
return uniqueID;
}
int hash = 7;
hash = 73 * hash + (this.uniqueID != null ? this.uniqueID.hashCode() : 0);
hash = 73 * hash + (this.startShift != null ? this.startShift.hashCode() : 0);
hash = 73 * hash + (this.endShift != null ? this.endShift.hashCode() : 0);
hash = 73 * hash + (this.facility != null ? this.facility.hashCode() : 0);
hash = 73 * hash + (this.schedule != null ? this.schedule.hashCode() : 0);
hash = 73 * hash + getClass().hashCode();
return hash;
}
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
public boolean equivalent(PeriodResident other) {
if (this == other) {
return true;
}
if (other == null) {
return false;
}
if (getClass() != other.getClass()) {
return false;
}
if (endShift == null) {
if (other.endShift != null) {
return false;
}
} else if (!endShift.equals(other.endShift)) {
return false;
}
if (facility == null) {
if (other.facility != null) {
return false;
}
} else if (!facility.equals(other.facility)) {
return false;
}
if (startShift == null) {
if (other.startShift != null) {
return false;
}
} else if (!startShift.equals(other.startShift)) {
return false;
}
if (schedule == null) {
if (other.getSchedule() != null) {
return false;
}
} else if (!schedule.equals(other.getSchedule())) {
return false;
}
return true;
}
public Date getStartShiftDate() {
return getStartShift().getTime();
}
public Date getEndShiftDate() {
return getEndShift().getTime();
}
/** The database unique id. */
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "id")
Integer uniqueID;
/** The start shift of the PeriodResident. */
@Column(name = "start_time")
@Convert(value="ShiftDateConverter")
Shift startShift;
/** The end shift of the PeriodResident.*/
@Column(name = "end_time")
@Convert(value="ShiftDateConverter")
Shift endShift;
/** The facility where the PeriodResident lives. */
@ManyToOne
@JoinColumn(name = "facility", referencedColumnName = "ID")
Facility facility;
@ManyToOne
@JoinColumn(name = "schedule", referencedColumnName = "ID")
private Schedule schedule;
}
package ohno;
import ohno.Experiment;
import ohno.Role;
import java.io.Serializable;
import javax.persistence.DiscriminatorValue;
import javax.persistence.Embedded;
import javax.persistence.Entity;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;
import javax.persistence.Transient;
/**
*
* @author Nick
*/
@Entity
@Table(name = "bs_blocks_experiment")
@NamedQueries({
@NamedQuery(name = "ExperimentBlock.findAll", query = "SELECT e FROM ExperimentBlock e"),
@NamedQuery(name = "ExperimentBlock.findActualByExperiment", query = "SELECT e FROM ExperimentBlock e WHERE e.experiment = :experiment AND e.schedule.scheduleProperties.revision = :active ORDER BY e.schedule.id DESC, e.uniqueID DESC"),
@NamedQuery(name = "ExperimentBlock.findByTime", query = "SELECT e FROM ExperimentBlock e WHERE e.startShift < :endTime AND e.endShift > :startTime and e.schedule = :schedule"),
@NamedQuery(name = "ExperimentBlock.findWithIdsBySchedule", query = "SELECT e, e.uniqueID FROM ExperimentBlock e WHERE e.schedule = :schedule")})
@DiscriminatorValue(value = "EXPERIMENT_BLOCK")
public class ExperimentBlock extends PeriodResident implements Serializable {
private static final long serialVersionUID = 1L;
// #########
// Some columns are inherited from PeriodResident!
// #########
@Embedded
protected Equipment equipment;
@ManyToOne
@JoinColumn(name = "experiment", referencedColumnName = "exp_id")
private Experiment experiment;
public ExperimentBlock() {
}
public Equipment getEquipment() {
return equipment;
}
public void setEquipment(Equipment equipment) {
this.equipment = equipment;
}
public Experiment getExperiment() {
return experiment;
}
public void setExperiment(Experiment experiment) {
this.experiment = experiment;
}
@Override
public boolean equivalent(PeriodResident pr) {
if (!super.equivalent(pr)) {
return false;
}
ExperimentBlock other = (ExperimentBlock) pr;
if (!getExperiment().equals(other.getExperiment())) {
return false;
}
if (!getEquipment().equals(other.getEquipment())) {
return false;
}
return true;
}
@Override
public ExperimentBlock clone() {
ExperimentBlock clone = new ExperimentBlock();
copyCharacteristics(this, clone);
clone.setExperiment(getExperiment());
clone.setEquipment(equipment.clone());
return clone;
}
@Override
public String getResidentType() {
return RESIDENT_TYPE;
}
@Transient
public static final String RESIDENT_TYPE = "ExperimentBlock";
@Override
public String toString() {
return "Experiment " + experiment + "\nChannel: " + getFacility()
+ "\nEquipment: " + getEquipment() + "\nFrom "
+ getStartShift() + "\nto " + getEndShift();
}
/**
* Gets an HTML string representation of this.
*
* @return the string
*/
public String toFancyString() {
return "<html>Experiment <b>" + (experiment.isNoExperiment() ? "N/A" : experiment) + "</b><br>Channel: " + getFacility()
+ "<br>Equipment: " + getEquipment() + "<br>From: <b>"
+ getStartShift().toString(Role.BEGINNING) + "</b><br>To: <b>" + getEndShift().toString(Role.ENDING)
+ "</b><br>Shift Count: <b>" + getShifts() + "</b></html>";
}
}
- 这个问题的黑客（即“cludge”）解决方案和优雅的解决方案绝对是受欢迎的。
- 我检查了数据库（表定义、外键等），但在
ExperientBlock中找不到任何可以解释我的问题的关于ExperientBlock的特殊信息。 - （来自下面的注释：）
ExperientBlock的所有其他持久属性都正确加载。用em.find()加载ExperientBlock会导致同样的问题。（上面，我从一个JPQL查询中加载了它，并将其作为另一个类schedule的属性。）
共有1个答案
胡飞舟
奇怪。这个对象一定与工作的兄弟姐妹有什么不同。
你可以试着缩小问题的范围，
- 对id列（以及所有其他列/表）使用大写字母“id”
- 尝试禁用编织，或禁用“eclipselink.weaving.internal”
- 尝试删除克隆/equals/hashcode方法
还启用日志记录，并包括为查询生成的SQL和完整的异常堆栈跟踪。
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