Adding SelectList Value into DB

[Kashif Mughal]

Hi,

With all my little knowledge with hibernate, I am trying to work on a relationship between CATEGORY and ITEMS. Its a simple one to many relationship but when i try to add an ITEM it also adds the category again for that item. That should not be the case; Category is just a select list in the Gui.

My poor mappings are as follow;

 <?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class
name="com.wondergas.common.impl.ItemImpl"
table="WG_ITEMS">
<id
name="id"
type="long"
column="ITEM_ID">
<generator class="sequence">
<param name="sequence">ID_SEQ</param>
</generator>
</id>
<property name="itemNumber">
<column name="ITEM_NO" />
</property>
<property name="description">
<column name="DESCRIPTION" />
</property>
<property name="imageUrl">
<column name="IMG_URL" />
</property>
<property name="color">
<column name="COLOR" />
</property>
<property name="weight">
<column name="WEIGHT" />
</property>
<property name="height">
<column name="HEIGHT" />
</property>
<property name="length">
<column name="LENGTH" />
</property>
<property name="price">
<column name="PRICE" />
</property>
<property name="quantity">
<column name="QUANTITY" />
</property>

<!-- Category -->
<many-to-one
name="category"
column="CATEGORY_ID"
cascade = "all"
class="com.wondergas.common.impl.CategoryImpl" />
<!-- Orders -->
<set
name="orderSet"
table="WG_ORDER_ITEM"
inverse="true"
lazy="true">
<key column="ITEM_ID" />
<many-to-many
class="com.wondergas.common.impl.OrderImpl"
column="ORDER_ID" />
</set>
</class>
</hibernate-mapping>
   

 <?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class
name="com.wondergas.common.impl.CategoryImpl"
table="WG_CATEGORIES">
<id
name="id"
type="long"
column="CATEGORY_ID">
<generator class="sequence">
<param name="sequence">ID_SEQ</param>
</generator>
</id>
<property name="Description">
<column name="DESCRIPTION" />
</property>
<!-- Items -->
<set
name="itemSet"
cascade="all"
inverse="true">
<key
column="CATEGORY_ID"
not-null="true" />
<one-to-many class="com.wondergas.common.impl.ItemImpl" />
</set>
</class>
</hibernate-mapping>
   

   protected Object formBackingObject(HttpServletRequest request) throws Exception {
ItemImpl item = new ItemImpl();
CategoryImpl cat = new CategoryImpl();
item.setCategory(cat);
return item;
    }
 
    protected Map referenceData(HttpServletRequest request) throws Exception {
 
Map model = new HashMap();
List categories = inventoryService.findAllCategories();
model.put("categories", categories);
return model;
    }
 
    // Creating Category into DB
    public void onBindAndValidate(HttpServletRequest request, Object command, BindException errors) throws Exception {

ItemImpl itm = (ItemImpl) command;

if (errors.hasErrors())
    return;

itm = inventoryService.addItem(itm);
    }   

  <spring:bind path="itemImpl.category.description">
<select name='<c :-o	 ut value="${status.expression}"/>'>
<option value=""></option>
<c:forEach items="${categories}" var="category">
<optionvalue='<c :-o	 ut value="${category.description}"/>'
<c:if test="${category.description == status.value}"> SELECTED</c:if>>
<c :-o	 ut value="${category.description}" />
</option>
</c:forEach>
</select>
</spring:bind>  

I know this is something very tiny but cant find, So Please F1 F1 F1

[Mark Spritzler]

Quick question. Are you setting both sides of the relationship. Meaning are you adding the Item to the collection in Category, and are you setting the Item's Category, and htat Category that you are adding being the one that has the id set. If you are adding a Category that doesn't have an id, then it will do an insert on that Category object.

Also, do you have interfaces for your domain objects? Usually you don't.

Mark

[Kashif Mughal]

Are you setting both sides of the relationship. Meaning are you adding the Item to the collection in Category, and are you setting the Item's Category, and htat Category that you are adding being the one that has the id set. If you are adding a Category that doesn't have an id, then it will do an insert on that Category object.

Yes I do have the bi-directional relationship, I mean Category has Set of Items and Item has Category object. When I am adding item, I expect to take the Category id from the Gui(selectList) that is populated from Categories in DB. I dont want it to add new category.

So, I might have done some wrong relationship or concept. Classes are as follow;

 
public class CategoryImpl {
 
    private Long id;
 
    private String description;
 
    private Set<ItemImpl> itemSet = new HashSet<ItemImpl>();
 
    public CategoryImpl() {
 
    }
 
    public CategoryImpl(long id, String desc) {
this.id = id;
this.description = desc;
    }
 
    public Long getId() {
return id;
    }
 
    public String getDescription() {
return description;
    }
 
    public Set<ItemImpl> getItemSet() {
return itemSet;
    }
 
    public void setId(Long id) {
this.id = id;
    }
 
    public void setDescription(String description) {
this.description = description;
    }
 
    public void setItemSet(Set<ItemImpl> itemSet) {
this.itemSet = itemSet;
    }
 
    public void addItem(ItemImpl item) {
this.itemSet.add(item);
if(item.getCategory() != this){
    item.setCategory(this);
}
    }  

  
public class ItemImpl implements InfAssemblyItems {
 
    private long id;
 
    private String itemNumber;
 
    private String description;
 
    private CategoryImpl category;
 
    public ItemImpl() {
 
    }
 
    public void assemble(ItemImpl item) {
 
// Get Assembly Details
// Check Stock
 
    }
 
    public void unassemble(ItemImpl item) {
 
    }
 
    public long getId() {
return id;
    }
 
    public String getItemNumber() {
return itemNumber;
    }
 
    public String getDescription() {
return description;
    }
 
    public void setId(long id) {
this.id = id;
    }
 
    public void setItemNumber(String itemNumber) {
this.itemNumber = itemNumber;
    }
 
    public void setDescription(String description) {
this.description = description;
    }
 
    public CategoryImpl getCategory() {
return category;
    }
 
    public void setCategory(CategoryImpl category) {
this.category = category;
    }
 

    public void addCategory(CategoryImpl cat) {
this.category = cat;
if (!category.getItemSet().contains(this)) {
    category.getItemSet().add(this);
}
    }
 
    }
  

About Interfaces for the Domain Objects I had them before but not now, just did not changed the names. By the way Which classes should have and not have interfaces ?