hbm2java with bound properties

willcodejavaforfood · **Joined:** Sun Dec 21, 2008 4:01 pm **Posts:** 4

Hello everyone,

I have recently customised the templates for generating POJOs with hbm2java to also generate bound properties and add PropertyChangeSupport instance to my POJOs. What worries me is that I really could not find much information about people doing stuff like this so my question to the hibernate community is: Are you designing your domain objects with bound properties?

Kind Regards,
Erik

max · **Posted:** Mon Dec 22, 2008 4:55 am

I don't since I find most of the time the model is more strict than I really would like it to be for an ui where propertychange listeners are the most useful - but there have been others that did it for the older hibernate tools but the change did not make it over since it was not easily moved from velocity to freemarker.

If you have done it how about contributed your fix ?

willcodejavaforfood · **Joined:** Sun Dec 21, 2008 4:01 pm **Posts:** 4

Certainly,

It might need some more work though. Let me try and outline what I have done first and I'll have a chance to do some enhancements if necessary.

I have a class level meta attribute "property-change-support" which will add the field propertyChangeSupport of the type java.beans.PropertyChangeSupport. It will also add the following methods:

Code:

public void firePropertyChange(String property, Object oldValue, Object newValue);

public void addPropertyChangeListener(String property, java.beans.PropertyChangeListener listener);

public void removePropertyChangeListener(String property, java.beans.PropertyChangeListener listener);

Any property with the following meta attribute "bound-property" will have a constant generated and its set method modified to something along the line of:

Code:

public static final String CREDIT_PROPERTY = "credit";

public void setCredit(double credit) {
        double old = this.credit;
        this.credit = credit;
        firePropertyChange("credit", Double.valueOf(old), Double.valueOf(this.credit));
    }

I have no support for indexed properties and at the moment you have to specify which properties you want to be bound.

max · **Posted:** Mon Dec 22, 2008 5:18 pm

in the old days meta could be bound and constrained to indicate the type of property change listener the user wanted.

willcodejavaforfood · **Joined:** Sun Dec 21, 2008 4:01 pm **Posts:** 4

max wrote:

in the old days meta could be bound and constrained to indicate the type of property change listener the user wanted.

You mean, bound, vetoable, indexed etc?

max · **Posted:** Wed Dec 24, 2008 6:27 am

yes - thats what i recall from reading the old hibernate 2 docs.

willcodejavaforfood · **Joined:** Sun Dec 21, 2008 4:01 pm **Posts:** 4

Do you think it would make more sense to have all properties bound instead of doing them individually?

max · **Posted:** Thu Dec 25, 2008 5:11 am

meta attributes is inherited by default so if you add <meta attribute="bound"/> at the class level every property will pick that up making them all bound.

Caleb666 · **Joined:** Sat Sep 03, 2011 10:16 am **Posts:** 10

If this feature used to exist in the old version, why has it been removed?

It's a really useful feature to have, for anyone doing DataBinding on the persistent objects.

Caleb666 · **Joined:** Sat Sep 03, 2011 10:16 am **Posts:** 10

willcodejavaforfood decided not to publish any source code, so I will post it here for posterity.

To use it simply add <meta attribute="property-change-support">true</meta> under your <class>.
And to add fields that fire the event, simply add <meta attribute="bound">FIELD_PROPERTY</meta> under the needed <property>.

FIELD_PROPERTY should be the unique name given to this property, and it will be exposed as a static string.

Pojo.ftl

Code:

${pojo.getPackageDeclaration()}
// Generated ${date} by Hibernate Tools ${version}

<#assign classbody>
<#include "PojoTypeDeclaration.ftl"/> {

<#if !pojo.isInterface()>
<#include "PojoFields.ftl"/>

<#include "PojoConstructors.ftl"/>
   
<#include "PojoPropertyAccessors.ftl"/>

<#include "PojoToString.ftl"/>

<#include "PojoEqualsHashcode.ftl"/>

<#else>
<#include "PojoInterfacePropertyAccessors.ftl"/>

</#if>
<#include "PojoExtraClassCode.ftl"/>

}
</#assign>

${pojo.generateImports()}
<#if pojo.hasMetaAttribute("property-change-support")>
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
</#if>
${classbody}

PojoFields.ftl

Code:

<#-- // Fields -->

<#foreach field in pojo.getAllPropertiesIterator()><#if pojo.getMetaAttribAsBool(field, "gen-property", true)> <#if pojo.hasMetaAttribute(field, "field-description")>    /**
     ${pojo.getFieldJavaDoc(field, 0)}
     */
 </#if>    ${pojo.getFieldModifiers(field)} ${pojo.getJavaTypeName(field, jdk5)} ${field.name}<#if pojo.hasFieldInitializor(field, jdk5)> = ${pojo.getFieldInitialization(field, jdk5)}</#if>;
</#if>
</#foreach>

<#if pojo.hasMetaAttribute("property-change-support")>
    // Property Change support
    <#foreach property in pojo.getAllPropertiesIterator()>  
    <#if pojo.hasMetaAttribute(property, "bound")> 
    public static final String ${c2j.getMetaAsString(property, "bound")} = "${property.name}";
    </#if>  
    </#foreach>
    
    private PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport(this);
    
    public void addPropertyChangeListener(String propertyName, PropertyChangeListener listener) {
        propertyChangeSupport.addPropertyChangeListener(propertyName, listener);
     }

     public void removePropertyChangeListener(PropertyChangeListener listener) {
        propertyChangeSupport.removePropertyChangeListener(listener);
     }    
</#if>

PojoPropertyAccessors.ftl

Code:

<#-- // Property accessors -->
<#foreach property in pojo.getAllPropertiesIterator()>
<#if pojo.getMetaAttribAsBool(property, "gen-property", true)>
 <#if pojo.hasFieldJavaDoc(property)>    
    /**       
     * ${pojo.getFieldJavaDoc(property, 4)}
     */
</#if>
    <#include "GetPropertyAnnotation.ftl"/>
    ${pojo.getPropertyGetModifiers(property)} ${pojo.getJavaTypeName(property, jdk5)} ${pojo.getGetterSignature(property)}() {
        return this.${property.name};
    }
    
    ${pojo.getPropertySetModifiers(property)} void set${pojo.getPropertyName(property)}(${pojo.getJavaTypeName(property, jdk5)} ${property.name}) {
     <#if pojo.hasMetaAttribute(property, "bound")>
       <#assign oldVal = "this.${property.name}">
       <#assign newVal = "this.${property.name} = ${property.name}">
       <#if pojo.getJavaTypeName(property, jdk5) == "byte">
         <#assign oldVal = "new Byte(this.${property.name})">
         <#assign newVal = "new Byte(this.${property.name} = ${property.name})">
       <#elseif  pojo.getJavaTypeName(property, jdk5) == "short">
         <#assign oldVal = "new Short(this.${property.name})">
         <#assign newVal = "new Short(this.${property.name} = ${property.name})">
       <#elseif  pojo.getJavaTypeName(property, jdk5) == "int">
         <#assign oldVal = "new Integer(this.${property.name})">
         <#assign newVal = "new Integer(this.${property.name} = ${property.name})">
       <#elseif  pojo.getJavaTypeName(property, jdk5) == "long">
         <#assign oldVal = "new Long(this.${property.name})">
         <#assign newVal = "new Long(this.${property.name} = ${property.name})">
       <#elseif  pojo.getJavaTypeName(property, jdk5) == "float">
         <#assign oldVal = "new Float(this.${property.name})">
         <#assign newVal = "new Float(this.${property.name} = ${property.name})">
       <#elseif  pojo.getJavaTypeName(property, jdk5) == "double">
         <#assign oldVal = "new Double(this.${property.name})">
         <#assign newVal = "new Double(this.${property.name} = ${property.name})">
       <#elseif  pojo.getJavaTypeName(property, jdk5) == "char">
         <#assign oldVal = "new Character(this.${property.name})">
         <#assign newVal = "new Character(this.${property.name} = ${property.name})">
       <#elseif  pojo.getJavaTypeName(property, jdk5) == "boolean">
         <#assign oldVal = "new Boolean(this.${property.name})">
         <#assign newVal = "new Boolean(this.${property.name} = ${property.name})">
       </#if>
        propertyChangeSupport.firePropertyChange(${c2j.getMetaAsString(property, "bound")}, ${oldVal}, ${newVal});
     <#else>
        this.${property.name} = ${property.name};
     </#if>
    }
</#if>
</#foreach>