Java 完全忽略Hibernate.initialize()
我有一个实体,它有一些延迟加载的属性,我正试图为一个特定的方法初始化这些属性(大多数情况下,加载这些属性的代价太高,所以不能将它们设置为“渴望”) 其中一个属性是集合,当调用Hibernate.initialize()时,它可以很好地加载。另一个是单个对象,无论我尝试什么,它都不会加载。我甚至无法查询它,因为对象的id本身不可用,即使在同一会话期间也不可用 调用initialize()时没有任何异常,只是被忽略了。当对集合而不是单个对象调用此函数时,日志将显示相应的查询。非常感谢您对加载此属性(设备)的任何帮助。代码如下: 编辑 结果发现我的数据库中缺少一个外键。一旦我纠正了这一点,fetch查询就会出现在控制台上,但是,initialize()完成后,设备对象仍然是一个代理。我通过这样做想出了一个解决办法:Java 完全忽略Hibernate.initialize(),java,hibernate,lazy-loading,Java,Hibernate,Lazy Loading,我有一个实体,它有一些延迟加载的属性,我正试图为一个特定的方法初始化这些属性(大多数情况下,加载这些属性的代价太高,所以不能将它们设置为“渴望”) 其中一个属性是集合,当调用Hibernate.initialize()时,它可以很好地加载。另一个是单个对象,无论我尝试什么,它都不会加载。我甚至无法查询它,因为对象的id本身不可用,即使在同一会话期间也不可用 调用initialize()时没有任何异常,只是被忽略了。当对集合而不是单个对象调用此函数时,日志将显示相应的查询。非常感谢您对加载此属性(
Device device = new Device();
device.setIdDevice(surveyLog.getDevice().getIdDevice());
device.setName(surveyLog.getDevice().getName());
surveyLog.setDevice(device);
如果将属性复制到另一个对象,则可以在方法外部访问这些属性,否则该对象仍将是代理。你知道这是什么原因吗?谢谢
@Transactional
public SurveyLog getById(Long id)
{
SurveyLog surveyLog = this.surveyLogDAO.findById(id);
Hibernate.initialize(surveyLog.getDevice()); //doesn't work
Hibernate.initialize(surveyLog.getSurveyAnswers()); //works like a charm
return surveyLog;
}
这些是我的映射:
import static javax.persistence.GenerationType.IDENTITY;
import java.math.BigDecimal;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import org.hibernate.annotations.Cascade;
import org.hibernate.annotations.CascadeType;
import org.hibernate.annotations.Fetch;
import org.hibernate.annotations.FetchMode;
import com.google.gson.annotations.Expose;
@Entity
@Table(name="SurveyLog")
public class SurveyLog
{
// Fields
@Expose private Long idSurveyLog;
@Expose private Survey survey;
@Expose private Device device;
@Expose private BigDecimal latitude;
@Expose private BigDecimal longitude;
@Expose private Timestamp timestamp;
@Expose private List<SurveyAnswerLog> surveyAnswers = new ArrayList<SurveyAnswerLog>();
/**
* Constructor.
*
*/
public SurveyLog() {}
// Property accessors
@Id
@GeneratedValue(strategy=IDENTITY)
@Column(name="idSurveyLog", unique=true, nullable=false)
public Long getIdSurveyLog()
{
return idSurveyLog;
}
public void setIdSurveyLog(Long idSurveyLog)
{
this.idSurveyLog = idSurveyLog;
}
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="idSurvey", nullable=false)
public Survey getSurvey()
{
return survey;
}
public void setSurvey(Survey survey)
{
this.survey = survey;
}
@ManyToOne(fetch=FetchType.LAZY)
@Fetch(value = FetchMode.SELECT)
@JoinColumn(name="idDevice", nullable=false)
public Device getDevice()
{
return device;
}
public void setDevice(Device device)
{
this.device = device;
}
@Column(name="latitude", precision=8, scale=6)
public BigDecimal getLatitude()
{
return latitude;
}
public void setLatitude(BigDecimal latitude)
{
this.latitude = latitude;
}
@Column(name="longitude", precision=9, scale=6)
public BigDecimal getLongitude()
{
return longitude;
}
public void setLongitude(BigDecimal longitude)
{
this.longitude = longitude;
}
@Column(name="timestamp", length=19)
public Timestamp getTimestamp()
{
return timestamp;
}
public void setTimestamp(Timestamp timestamp)
{
this.timestamp = timestamp;
}
@OneToMany(fetch=FetchType.LAZY, mappedBy="surveyLog")
@Cascade({CascadeType.ALL, CascadeType.DELETE_ORPHAN})
public List<SurveyAnswerLog> getSurveyAnswers()
{
return surveyAnswers;
}
public void setSurveyAnswers(List<SurveyAnswerLog> surveyAnswers)
{
this.surveyAnswers = surveyAnswers;
}
}
import static javax.persistence.GenerationType.IDENTITY;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
import javax.persistence.Version;
import com.google.gson.annotations.Expose;
import com.sitei.base.model.City;
import com.sitei.base.model.Company;
@Entity
@Table(name="Device", uniqueConstraints = @UniqueConstraint(columnNames = "macAddress"))
public class Device
{
// Fields
@Expose private Integer idDevice;
@Expose private String macAddress;
@Expose private String name;
@Expose private String description;
@Expose private Short type;
@Expose private City city;
@Expose private Company company;
@Expose private Survey survey;
@Expose private Integer surveyPoints;
@Expose private boolean active;
@Expose private Long version;
/**
* Constructor.
*
*/
public Device() {}
// Property accessors
@Id
@GeneratedValue(strategy=IDENTITY)
@Column(name="idDevice", unique=true, nullable=false)
public Integer getIdDevice()
{
return idDevice;
}
public void setIdDevice(Integer idDevice)
{
this.idDevice = idDevice;
}
@Column(name="macAddress", nullable=false, length=17)
public String getMacAddress()
{
return macAddress;
}
public void setMacAddress(String macAddress)
{
this.macAddress = macAddress;
}
@Column(name="name", nullable=false, length=64)
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
@Column(name="description", length=256)
public String getDescription()
{
return description;
}
public void setDescription(String description)
{
this.description = description;
}
@Column(name="type", nullable=false)
public Short getType()
{
return type;
}
public void setType(Short type)
{
this.type = type;
}
@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="idCity", nullable=false)
public City getCity()
{
return city;
}
public void setCity(City city)
{
this.city = city;
}
@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="idCompany")
public Company getCompany()
{
return company;
}
public void setCompany(Company company)
{
this.company = company;
}
@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="idSurvey")
public Survey getSurvey()
{
return survey;
}
public void setSurvey(Survey survey)
{
this.survey = survey;
}
@Column(name="surveyPoints", nullable=false)
public Integer getSurveyPoints()
{
return surveyPoints;
}
public void setSurveyPoints(Integer surveyPoints)
{
this.surveyPoints = surveyPoints;
}
@Column(name="active", nullable=false)
public boolean isActive()
{
return active;
}
public void setActive(boolean active)
{
this.active = active;
}
@Version
public Long getVersion()
{
return version;
}
public void setVersion(Long version)
{
this.version = version;
}
}
导入静态javax.persistence.GenerationType.IDENTITY;
导入java.math.BigDecimal;
导入java.sql.Timestamp;
导入java.util.ArrayList;
导入java.util.List;
导入javax.persistence.Column;
导入javax.persistence.Entity;
导入javax.persistence.FetchType;
导入javax.persistence.GeneratedValue;
导入javax.persistence.Id;
导入javax.persistence.JoinColumn;
导入javax.persistence.manytone;
导入javax.persistence.OneToMany;
导入javax.persistence.Table;
导入org.hibernate.annotations.Cascade;
导入org.hibernate.annotations.CascadeType;
导入org.hibernate.annotations.Fetch;
导入org.hibernate.annotations.FetchMode;
导入com.google.gson.annotations.Expose;
@实体
@表(name=“SurveyLog”)
公共类调查
{
//田地
@公开私有长idSurveyLog;
@公开私人调查;
@公开私有设备;
@公开私人信息;
@公开私有数据;
@公开私有时间戳;
@Expose private List surveyAnswers=new ArrayList();
/**
*构造器。
*
*/
公共调查日志(){}
//属性访问器
@身份证
@生成值(策略=标识)
@列(name=“idSurveyLog”,unique=true,nullable=false)
公共长getIdSurveyLog()
{
返回idSurveyLog;
}
公共无效集合idSurveyLog(长idSurveyLog)
{
this.idSurveyLog=idSurveyLog;
}
@manytone(fetch=FetchType.LAZY)
@JoinColumn(name=“idSurvey”,nullable=false)
公众调查
{
回归调查;
}
公共调查(调查)
{
这个调查=调查;
}
@manytone(fetch=FetchType.LAZY)
@获取(值=获取模式。选择)
@JoinColumn(name=“idDevice”,nullable=false)
公共设备getDevice()
{
返回装置;
}
公共无效设置设备(设备)
{
这个装置=装置;
}
@列(名称=“纬度”,精度=8,刻度=6)
公共BigDecimal getLatitude()
{
返回纬度;
}
公共void设置纬度(BigDecimal纬度)
{
这个。纬度=纬度;
}
@列(名称=“经度”,精度=9,刻度=6)
公共bigdecim getLongitude()
{
返回经度;
}
公共无效设置经度(BigDecimal经度)
{
这个经度=经度;
}
@列(name=“timestamp”,长度=19)
公共时间戳getTimestamp()
{
返回时间戳;
}
public void setTimestamp(Timestamp Timestamp)
{
this.timestamp=时间戳;
}
@OneToMany(fetch=FetchType.LAZY,mappedBy=“surveyLog”)
@级联({CascadeType.ALL,CascadeType.DELETE_ORPHAN})
公共列表getSurveyAnswers()
{
返回调查和回答;
}
公共无效设置调查和回答者(列表调查和回答者)
{
this.surveyAnswers=surveyAnswers;
}
}
导入静态javax.persistence.GenerationType.IDENTITY;
导入java.util.EnumSet;
导入java.util.HashMap;
导入java.util.Map;
导入javax.persistence.Column;
导入javax.persistence.Entity;
导入javax.persistence.FetchType;
导入javax.persistence.GeneratedValue;
导入javax.persistence.Id;
导入javax.persistence.JoinColumn;
导入javax.persistence.manytone;
导入javax.persistence.Table;
导入javax.persistence.UniqueConstraint;
导入javax.persistence.Version;
导入com.google.gson.annotations.Expose;
导入com.sitei.base.model.City;
导入com.sitei.base.model.Company;
@实体
@表(name=“Device”,uniqueConstraints=@UniqueConstraint(columnNames=“macAddress”))
公共类设备
{
//田地
@公开私有整数设备;
@公开私有字符串macAddress;
@公开私有字符串名称;
@公开私有字符串描述;
@公开私人短型;
@揭露私人城市;
@揭露私人公司;
@公开私人调查;
@公开私有整数测量点;
@公开私有布尔活动;
@公开私有长版本;
/**
*构造器。
*
*/
公用设备(){}
//属性访问器
@身份证
@生成值(策略=标识)
@列(name=“idDevice”,unique=true,nullable=false)
公共整数getIdDevice()
{
返回装置;
}
public void setIdDevice(整数idDevice)
{
this.idDevice=idDevice;
}
@列(name=“macAddress”,null=false,长度=17)
公共字符串getMacAddress()
{
返回macAddress;
}
public void setMacAddress(字符串macAddress)
{
this.macAddress=macAddress;
}
@列(name=“name”,nullable=false,length=64)
公众的
List<String> methodNames= new ArrayList();
methodNames.add("getScTeamUserses");
public T getByID(PK id, List<String> methodNames) {
T object = null;
Session sess = getSession();
try {
sess.beginTransaction();
object = (T) sess.get(clazz, id);
Class[] clazz = null;
for (String methodName : methodNames) {
Method method = object.getClass().getMethod(methodName, clazz);
Hibernate.initialize(method.invoke(object, clazz));
}
sess.getTransaction().commit();
} catch (Exception e) {
logger.error("getByID id=" + id, e);
try {
sess.getTransaction().rollback();
throw e;
} catch (Exception ex) {
logger.error("getByID methodNames id=" + id, e);
}
} finally {
closeSession(sess);
}
return object;
}