Creation dynamic attributes

I solved a recurrent trouble when an entity need dynamics fields depending on it's own subcategory or class.

Here's my solution

db schema
DROP TABLE IF EXISTS attribute CASCADE;
CREATE TABLE attribute (
id_attribute SERIAL,
ref_subcategory integer REFERENCES subcategory(id_subcategory),
ref_message integer NOT NULL,
name varchar,
PRIMARY KEY (id_attribute)
);

DROP TABLE IF EXISTS value CASCADE;
CREATE TABLE value (
id_value SERIAL,
ref_attribute integer REFERENCES attribute(id_attribute),
ref_article integer,
value varchar NOT NULL,
PRIMARY KEY (id_value)
);

code from web tier :

Since my attributes depends on the subcategories I make a call to buildFields(1, 1) into it :

public void loadSubategories(int id) {
logger.info("loadSubategories Begin");
categoriesSelect.setContext(getContext());
categoriesSelect.bindRequestValue();
String categoryString = categoriesSelect.getValue();
if (categoryString != null && categoryString.length() > 0) {
int index = categoryString.indexOf("category=") + 9;
id = Integer.valueOf(categoryString.substring(index));
}
subcategoriesSelect.setContext(getContext());
subcategoriesSelect.bindRequestValue();
String subcategoryString = subcategoriesSelect.getValue();
Option selected = null;
if (subcategoryString != null && subcategoryString.length() > 0) {
int index = subcategoryString.indexOf("subcat=") + 7;
id = Integer.valueOf(subcategoryString.substring(index));
SubcategoryBU selectedCat = subcategoryService.findById(id);
selected = new Option("/auction/add_other.html?action=loadSubcat&category=" + id + "&subcat=",selectedCat.getText(lang));
selected.setSelected(true);
subcategoriesSelect.add(selected);
}
CategoryBU categoryBu = categoryService.findById(id, lang);
subcategories = subcategoryService.findAllSubcategory(categoryBu);
for (int i = 0; i < subcategory =" subcategories.get(i);" option =" new" action="loadSubcat&category="" subcat=" + subcategory.getSubcategoryId(),subcategory.getText(lang)); subcategoriesSelect.add(option); } subcategoriesSelect.setAttribute(" idcat = " + idCat + " idsubcat =" " categorystring =" categoriesSelect.getValue();"> 0) {
int index = categoryString.indexOf("category=") + 9;
idCat = Integer.valueOf(categoryString.substring(index));
}
subcategoriesSelect.setContext(getContext());
subcategoriesSelect.bindRequestValue();
String subcategoryString = subcategoriesSelect.getValue();
if (subcategoryString != null && subcategoryString.length() > 0) {
int index = subcategoryString.indexOf("subcat=") + 7;
idSubcat = Integer.valueOf(subcategoryString.substring(index));
}
if (idCat > 1 && idSubcat == 1)
idSubcat = categoryService.findFirstSubcategoryId(idCat);
AttributeBusinessServiceImpl attributeBusinessService = new AttributeBusinessServiceImpl();
List attributes = attributeBusinessService.findAllBySubcategory(idSubcat, lang);
for (int i = 0; i < attribute =" attributes.get(i);" name =" attribute.getText(lang).replace('" textfieldatribute =" new"> attributes = attributeBusinessService.findAllBySubcategory(idSubcat, lang)