Package uk.ac.ebi.utils.orm

Class Many2ManyUtils

java.lang.Object
uk.ac.ebi.utils.orm.Many2ManyUtils
public class Many2ManyUtils extends Object
Facilities to manager many-to-many relations in JPA.
date
Mar 25, 2013
Author:
Marco Brandizi

  • Constructor Details

    • Many2ManyUtils

      public Many2ManyUtils()

  • Method Details

    • addMany2Many

      public static <O, A> boolean addMany2Many(O obj, A added, String inverseRelationAddMethod, Collection<A> internalCollection)
      Synchronises the addition of an object to a many2many relationship. For example, if you have: Product.orders and Order.products, you can implement: 
      boolean Product.addOrder( Order prod )
      as: 
      return addManyToMany ( this, order, "addProduct", this.orders ); // or this.getOrders()
      where this.orders is the set internal to Product that backs the corresponding relation. This call invokes this.orders.add ( order ) and, in case this operation returns true (i.e., the order was not already inside the collection), it invokes order.addProduct ( this ) too. You should implement Order.product() in a dual way. The check that the element was added to the set avoids infinite loops.
      Parameters:
      obj - the object to which added is added
      added - the added object
      inverseRelationAddMethod - the name of the method to be called to add obj to added, using the inverse side of the relation obj-added relation.
      internalCollection - the collection for the side from obj to added to which added is actually added
      Returns:
      true if the added was really added to obj.

    • deleteMany2Many

      public static <O, A> boolean deleteMany2Many(O obj, A deleted, String inverseRelationDeleteMethod, Collection<A> internalCollection)
      The opposite of addMany2Many(Object, Object, String, Collection), the parameters and the return value have an analogous meaning.