Below is the code and mappings I use in my:
Persistent objects:
package test;
import org.apache.commons.lang.builder.ToStringBuilder;
/**
* @hibernate.class
* table="Parent"
* proxy="test.Parent"
*/
public class Parent {
private Long parentId;
private Integer version;
private String field;
private Child child;
public Parent() {
}
/** Getter for property parentId.
* @hibernate.id
* generator-class="seqhilo"
* type="long"
* column="ParentId"
* unsaved-value="null"
* @hibernate.generator-param
* name="sequence"
* value="parent_sequence"
* @return Value of property parentId.
*
*/
public java.lang.Long getParentId() {
return parentId;
}
/** Setter for property parentId.
* @param parentId New value of property parentId.
*
*/
protected void setParentId(java.lang.Long parentId) {
this.parentId = parentId;
}
/** Getter for property version.
* @hibernate.version
* column=Version
* type=integer
* @return Value of property version.
*
*/
public java.lang.Integer getVersion() {
return version;
}
/** Setter for property version.
* @param version New value of property version.
*
*/
protected void setVersion(java.lang.Integer version) {
this.version = version;
}
/** Getter for property field.
* @hibernate.property
* column="Field"
* type="string"
* length="50"
* @return Value of property field.
*
*/
public java.lang.String getField() {
return field;
}
/** Setter for property field.
* @param field New value of property field.
*
*/
public void setField(java.lang.String field) {
this.field = field;
}
/** Getter for property child.
* @hibernate.one-to-one
* name="child"
* class="test.Child"
* cascade="save-update"
* outer-join="false"
* constrained="false"
* property-ref="parent"
* @return Value of property child.
*
*/
public test.Child getChild() {
return child;
}
/** Setter for property child.
* @param child New value of property child.
*
*/
public void setChild(test.Child child) {
this.child = child;
}
public String toString(){
return ToStringBuilder.reflectionToString(this).toString();
}
}
package test;
import org.apache.commons.lang.builder.ToStringBuilder;
/**
* @hibernate.class
* table="Child"
* proxy="test.Child"
*/
public class Child {
private Long childId;
private Integer version;
private String field;
private Parent parent;
public Child() {
}
/** Getter for property childId.
* @hibernate.id
* generator-class="seqhilo"
* type="long"
* column="ChildId"
* unsaved-value="null"
* @hibernate.generator-param
* name="sequence"
* value="child_sequence"
* @return Value of property childId.
*
*/
public java.lang.Long getChildId() {
return childId;
}
/** Setter for property childId.
* @param childId New value of property childId.
*
*/
public void setChildId(java.lang.Long childId) {
this.childId = childId;
}
/** Getter for property version.
* @return Value of property version.
*
*/
public java.lang.Integer getVersion() {
return version;
}
/** Setter for property version.
* @param version New value of property version.
*
*/
public void setVersion(java.lang.Integer version) {
this.version = version;
}
/** Getter for property field.
* @hibernate.property
* column="Field"
* type="string"
* length="50"
* @return Value of property field.
*
*/
public java.lang.String getField() {
return field;
}
/** Setter for property field.
* @param field New value of property field.
*
*/
public void setField(java.lang.String field) {
this.field = field;
}
/** Getter for property parent.
* @hibernate.many-to-one
* column="ParentId"
* class="test.Parent"
* cascade="none"
* not-null="true"
* outer-join="false"
* @return Value of property parent.
*
*/
public test.Parent getParent() {
return parent;
}
/** Setter for property parent.
* @param parent New value of property parent.
*
*/
public void setParent(test.Parent parent) {
this.parent = parent;
}
public String toString(){
return new ToStringBuilder(this)
.append("childId", childId)
.append("field", field)
.append("version", version)
.toString();
}
}
Mappings:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class
name="test.Parent"
table="Parent"
proxy="test.Parent"
dynamic-update="false"
>
<id
name="parentId"
column="ParentId"
type="long"
unsaved-value="null"
>
<generator class="seqhilo">
<param name="sequence">parent_sequence</param>
</generator>
</id>
<version
name="version"
type="java.lang.Integer"
column="version"
/>
<property
name="field"
type="string"
update="true"
insert="true"
column="Field"
length="50"
/>
<one-to-one
name="child"
class="test.Child"
cascade="save-update"
outer-join="false"
constrained="false"
property-ref="parent"
/>
</class>
</hibernate-mapping>
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class
name="test.Child"
table="Child"
proxy="test.Child"
dynamic-update="false"
>
<id
name="childId"
column="ChildId"
type="long"
unsaved-value="null"
>
<generator class="seqhilo">
<param name="sequence">child_sequence</param>
</generator>
</id>
<property
name="field"
type="string"
update="true"
insert="true"
column="Field"
length="50"
/>
<many-to-one
name="parent"
class="test.Parent"
cascade="none"
outer-join="false"
update="true"
insert="true"
column="ParentId"
not-null="true"
/>
</class>
</hibernate-mapping>
Test methods:
private static void createParent() throws HibernateException {
Transaction tx = null;
Session session = null;
Parent parent = new Parent();
parent.setField("Parent_Field");
Child child = new Child();
child.setField("Child_Field");
parent.setChild(child);
child.setParent(parent);
try {
session = sessionFactory.openSession();
tx = session.beginTransaction();
session.save(parent);
tx.commit();
}
catch (HibernateException he) {
if(tx!=null)
tx.rollback();
throw he;
}
finally {
if(session != null){
session.close();
}
}
}
public static Parent getParent(Long parentId) throws HibernateException{
Parent parent = null;
Transaction tx = null;
Session session = null;
try {
session = sessionFactory.openSession();
tx = session.beginTransaction();
parent = (Parent)session.load(Parent.class, parentId);
tx.commit();
}
catch (HibernateException he) {
if(tx!=null)
tx.rollback();
throw he;
}
finally {
if(session != null){
session.close();
}
return parent;
}
}
I create a parent with the method createParent().
These are the issues I have:
1- If I remove proxy="test.Parent" from the parent's mapping, getParent always returns the parent with the child (sqls to get parent and child are executed, and parent.toString() executed after the session is closed shows the child):
Dec 6, 2003 4:04:17 PM net.sf.hibernate.cache.QueryCache <init>
INFO: starting query cache at region: net.sf.hibernate.cache.QueryCache
Hibernate: select parent0_.ParentId as ParentId0_, parent0_.version as version0_, parent0_.Field as Field0_ from Parent parent0_ where parent0_.ParentId=?
Hibernate: select child0_.ChildId as ChildId0_, child0_.Field as Field0_, child0_.ParentId as ParentId0_ from Child child0_ where child0_.ParentId=?
Found parent: test.Parent@15e0873[parentId=21,version=0,field=Parent_Field,child=test.Child@b7ec5d[childId=11,field=Child_Field,version=<null>]]
2- If I keep proxy="test.Parent" in the parent's mapping, the parent loaded by getParent() is not initialized (no sql is executed by Hibernate), and when I try use it I get the following exception:
INFO: starting update timestamps cache at region: net.sf.hibernate.cache.UpdateTimestampsCache
Dec 6, 2003 3:57:15 PM net.sf.hibernate.cache.QueryCache <init>
INFO: starting query cache at region: net.sf.hibernate.cache.QueryCache
Dec 6, 2003 3:57:15 PM net.sf.hibernate.proxy.LazyInitializer initializeWrapExceptions
SEVERE: Exception initializing proxy
net.sf.hibernate.HibernateException: Could not initialize proxy - the owning Session was closed
at net.sf.hibernate.proxy.LazyInitializer.initialize(LazyInitializer.java:46)
at net.sf.hibernate.proxy.LazyInitializer.initializeWrapExceptions(LazyInitializer.java:56)
at net.sf.hibernate.proxy.LazyInitializer.getImplementation(LazyInitializer.java:156)
at net.sf.hibernate.proxy.CGLIBLazyInitializer.intercept(CGLIBLazyInitializer.java:72)
at test.Parent$$EnhancerByCGLIB$$faa41c66.toString(<generated>)
at java.lang.String.valueOf(String.java:2177)
at java.lang.StringBuffer.append(StringBuffer.java:361)
at hibernate.Test.main(Test.java:26)
What am I missing to have lazy initialization for the child. I also need keep proxy="test.Parent" in the parent's mapping, as the parent is part of a graph, and I need this object also to be lazily initialized.
mota
Login
FAQ
Search
