Error while Persisting an Object

SureshSetty · **Posted:** Tue May 23, 2006 2:21 am

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Hi All, I'm having a problem while persisting an object which uses a reference.
I'm having two tables
1.Dept and
2.Emp
The database schema is...

Code:

Dept:
       Deptno int(11)   Pri
       Dname varchar(255) 
       Loc varchar(255) 

Code:

Emp:
       Empno  int(11) PRI
       Ename  varchar(255) 
       Job       varchar(255)
       Mgr       int(11)
       HireDate date
       Sal        float
       Comm   float
       Deptno  int(11)  MUL References Dept(deptno)

The Mapping XML files are:
The corresponding DTD's are not given.
Dept.hbm.xml :

Code:

<hibernate-mapping package="src.test">
  <class name="Dept" table="dept">
     <id name="deptno" column="Deptno" />
     <property name="dname" column="Dname" />
     <property name="loc" column="Loc" />
  </class>
</hibernate-mapping>

<br><br>
Emp.hbm.xml:

Code:

<hibernate-mapping package="src.test">
  <class name="src.test.Emp" table="emp">
     <id name="empno"  column="Empno" />
     <property name="ename" column="Ename" />
     <property name="job" column="Job" />
     <property name="mgr" column="Mgr" />
     <property name="hiredate" column="HireDate" />
     <property name="sal" column="Sal" />
     <property name="comm" column="Comm" />
    <many-to-one name="Deptno" class="src.test.Dept" column="DeptNo" not-null="false" />
   </class>
</hibernate-mapping>

The Corresponding Pojo's are:
Dept.java

Code:

package src.test;
public class Dept{
  private Integer deptno;
  private String dname;
  private String loc;
  public Dept(){
  //Default Constructor
  }
  public Integer getDeptno(){ return deptno; }
  public void setDeptno(Integer deptno){
     this.deptno=deptno;
  }

  public String getDname(){ return dname; }
  public void setDname(String dname){
     this.dname=dname;
  }

  public String getLoc(){ return loc; }
  public void setLoc(String loc){
     this.loc=loc;
  }

 }

Emp.java

Code:

package src.test;
import java.sql.Date;
public class Emp{
  private Integer empno;
  private String ename;
  private String job;
  private int mgr;
  private Date hiredate;
  private float sal;
  private float comm;
  private Integer deptno;
  public Emp(){
  //Default Contructor
  }
  public Integer getEmpno(){ return empno; }
  public void setEmpno(Integer empno){
     this.empno=empno;
  }

  public String getEname(){ return ename; }
  public void setEname(String ename){
     this.ename=ename;
  }

  public String getJob(){ return job; }
  public void setJob(String job){
     this.job=job;
  }

  public int getMgr(){ return mgr; }
  public void setMgr(int mgr){
     this.mgr=mgr;
  }

  public Date getHiredate(){ return hiredate; }
  public void setHiredate(Date hiredate){
     this.hiredate=hiredate;
  }

  public float getSal(){ return sal; }
  public void setSal(float sal){
     this.sal=sal;
  }

  public float getComm(){ return comm; }
  public void setComm(float comm){
     this.comm=comm;
  }

  public Integer getDeptno(){ return deptno; }
  public void setDeptno(Integer deptno){
   this.deptno=deptno;
  }
  
 }

Hibernate version: 3.1.3

Mapping documents:Dept.hbm.xml and Emp.hbm.xml

Code between sessionFactory.openSession() and session.close():
session.beginTransaction();
Integer deptNo=new Integer(10);
emp.setEmpno(new Integer(1));
emp.setEname("Robin");
emp.setDeptno(deptNo);
emp.setComm(0.0f);
emp.setHiredate(new Date(04,04,04));
emp.setJob("Junior");
emp.setMgr(1);
emp.setSal(9200f);
session.saveOrUpdate(emp);
session.getTransaction().commit();

Full stack trace of any exception that occurs:
11:04:30,406 ERROR BasicPropertyAccessor:167 - IllegalArgumentException in class: src.test.Dept, getter method of property: deptno
org.hibernate.PropertyAccessException: IllegalArgumentException occurred calling getter of src.test.Dept.deptno
at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:171)
at org.hibernate.tuple.AbstractEntityTuplizer.getIdentifier(AbstractEntityTuplizer.java:176)
at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:3257)
at org.hibernate.persister.entity.AbstractEntityPersister.isTransient(AbstractEntityPersister.java:2983)
at org.hibernate.engine.ForeignKeys.isTransient(ForeignKeys.java:181)
at org.hibernate.engine.ForeignKeys$Nullifier.isNullifiable(ForeignKeys.java:137)
at org.hibernate.engine.ForeignKeys$Nullifier.nullifyTransientReferences(ForeignKeys.java:69)
at org.hibernate.engine.ForeignKeys$Nullifier.nullifyTransientReferences(ForeignKeys.java:47)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:263)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:167)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:114)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:186)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:175)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:98)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:502)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:494)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:490)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:301)
at $Proxy0.saveOrUpdate(Unknown Source)
at classes.Transactions.insertIntoEmp(Transactions.java:256)
at classes.Transactions.insertRecord(Transactions.java:199)
at classes.Transactions.main(Transactions.java:37)
Caused by: java.lang.IllegalArgumentException: object is not an instance of declaring class
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:145)
... 26 more

Name and version of the database you are using:mysql-5.0.18

The generated SQL (show_sql=true):
select emp_.Empno, emp_.Ename as Ename1_, emp_.Job as Job1_, emp_.Mgr as Mgr1_, emp_.HireDate as HireDate1_, emp_.Sal as Sal1_, emp_.Comm as Comm1_, emp_.DeptNo as DeptNo1_ from emp emp_ where emp_.Empno=?

Debug level Hibernate log excerpt:
391 DEBUG IntegerType:80 - binding '1' to parameter: 1

I don't know why it is showing the error when i'm trying to persist an Emp object. But persisting an Dept object is working.
Please help me.
Any suggestions are appreciated.[/u]

zzyborg · **Posted:** Tue May 23, 2006 5:36 am

use cascade ="save-update" on the association mapping for department in employee

<many-to-one name="Deptno" class="src.test.Dept" column="DeptNo" not-null="false" cascade="save-update"/>

SureshSetty · **Posted:** Tue May 23, 2006 6:31 am

As i made that modification, it is still showing the same exception.
But thanks for your suggestion.

zzyborg · **Posted:** Tue May 23, 2006 6:38 am

i noticed something in ur Emp class

the deptNo is supposed to be of type Dept

public class Emp{
private Integer empno;
private String ename;
private String job;
private int mgr;
private Date hiredate;
private float sal;
private float comm;
(--) private Integer deptno;
(+) private Dept deptno ;

public Emp(){
//Default Contructor
}

SureshSetty · **Posted:** Tue May 23, 2006 7:00 am

Thank you. Whether i have to make any changes, to the code while inserting i.e., in between creating and saving object in the session?

zzyborg · **Posted:** Tue May 23, 2006 7:19 am

it can be somewhat like this

Code:

Emp emp = new Emp();

emp.setEmpno(new Integer(1));
emp.setEname("Robin");

//emp.setDeptno(deptNo);

Dept d = new Dept();
...
...
emp.setDeptno(d); // set the dept instance to be cascaded 

emp.setComm(0.0f);
emp.setHiredate(new Date(04,04,04));
emp.setJob("Junior");
emp.setMgr(1);
emp.setSal(9200f);

session.saveOrUpdate(emp);

SureshSetty · **Posted:** Tue May 23, 2006 7:33 am

Thank you Sherlin. Its working now. But i don't know why it is required? Can you explain me that?

Actually i'm a new member to the forums and i'm thinking that it may take day's to get response. But its not like that. Thanks again for your suggestions........:)

zzyborg · **Posted:** Tue May 23, 2006 7:51 am

SureshSetty wrote:

But i don't know why it is required?

well,i think it has nothing to do with the hibernate , just part of object oriented design if u were asking about the Dept stuff .

if it was about the mapping , refer the documentation