Web serwis przesłanie listy obiektów błąd mapowania na XML

Witam posiadam trzy klasy encji

package pl.luppo.ztz.model;

import java.io.Serializable;
import java.util.List;

import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlType;
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "product", propOrder = {
    "category",
    "manufacturer",
    "price",
    "purchasePositions"
})
@Entity
@NamedQueries({
	@NamedQuery(name = Product.ALL, query = "SELECT p FROM Product p  "),
    @NamedQuery(name = Product.TOTAL, query = "SELECT COUNT(p) FROM Product p")})
public class Product extends AbstractEntity implements Serializable {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	public final static String ALL = "PRODUCT_ALL";
	public final static String TOTAL = "PRODUCT_TOTAL";


	private Double price;
	@ManyToOne(fetch = FetchType.LAZY)
	@JoinColumn(name = "MANUFACTURER_ID")
	private Manufacturer manufacturer;
//	@ManyToMany(mappedBy="products")
	
	@ManyToOne(fetch = FetchType.LAZY)
	@JoinColumn(name = "CATEGOTY_ID")
	private Category category;
	@OneToMany(mappedBy="product")
	@XmlElement(nillable = true)
	private List<PurchasePosition> purchasePositions;
	



	public Double getPrice() {
		return price;
	}

	public void setPrice(Double price) {
		this.price = price;
	}



	public Manufacturer getManufacturer() {
		return manufacturer;
	}

	public void setManufacturer(Manufacturer manufacturer) {
		this.manufacturer = manufacturer;
	}


	public Category getCategory() {
		return category;
	}

	public void setCategory(Category category) {
		this.category = category;
	}

	public List<PurchasePosition> getPurchasePositions() {
		return purchasePositions;
	}

	public void setPurchasePositions(List<PurchasePosition> purchasePositions) {
		this.purchasePositions = purchasePositions;
	}



}

```java
package pl.luppo.ztz.model;

import java.util.List;

import javax.persistence.Entity;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlType;

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "category", propOrder = { "products" })
@Entity
@NamedQueries({ @NamedQuery(name = Category.ALL, query = "SELECT c FROM Category c  "),
		@NamedQuery(name = Category.TOTAL, query = "SELECT COUNT(c) FROM Category c") })
public class Category extends AbstractEntity {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	public final static String ALL = "CATEGORY_ALL";
	public final static String TOTAL = "CATEGORY_TOTAL";
	@XmlElement(nillable = true)
	@OneToMany(mappedBy = "category")
	private List<Product> products;

	public List<Product> getProducts() {
		return products;
	}

	public void setProducts(List<Product> products) {
		this.products = products;
	}

}

package pl.luppo.ztz.model;

import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlType;

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "purchasePosition", propOrder = { "count", "product", "purchase" })
@Entity
public class PurchasePosition extends AbstractEntity {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	private int count = 1;
	@ManyToOne(fetch = FetchType.LAZY)
	@JoinColumn(name = "PRODUCT_ID")
	private Product product;

	@ManyToOne(fetch = FetchType.LAZY)
	@JoinColumn(name = "PURCHASE_ID")
	private Purchase purchase;

	public int getCount() {
		return count;
	}

	public void setCount(int count) {
		this.count = count;
	}

	public Product getProduct() {
		return product;
	}

	public void setProduct(Product product) {
		this.product = product;
	}

	public Purchase getPurchase() {
		return purchase;
	}

	public void setPurchase(Purchase purchase) {
		this.purchase = purchase;
	}

}

Gdy przesyłam listę obiektów PurchasePosition bez uzupełnionego obiektu produkt (czyli sam obiekt PurchasePosition z id) to wszystko jest dobrze ale gdy tą liste uzupełnię o produkty to mam błąd

 
ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/Industry].[Faces Servlet]] (http-localhost-127.0.0.1-8080-6) Servlet.service() for servlet Faces Servlet threw exception: com.sun.istack.SAXException2: A cycle is detected in the object graph. This will cause infinitely deep XML: pl.luppo.ztz.model.Product@12fb848 -> pl.luppo.ztz.model.Category@177c6e9 -> pl.luppo.ztz.model.Product@12fb848
	

Wyczytałem że pomaga adnotacja

@XmlAccessorType(XmlAccessType.FIELD)

ale ja już mam ją w swoich encjach. Przesyłanie listy jest za pomocą

public void sendToWS(){
		 IndustryWSImplService industryService = new IndustryWSImplService();
			IndustryWS hello = industryService.getIndustryWSImplPort();
	 
			System.out.println("***********************************************************");
			hello.purchaseWS(purchase);
			hello.purchasePositions(initPurchasePositions);
	}

Jeszcze raz podkreślę że jeśli initPurchasePositions zawiera same obiekty PurchasePositions bez produktów wszystko działa poprawnie.

Proszę o pomoc jakich adnotacji użyć aby Parent->child był dobrze mapowany do XML

Z góry dziękuję za pomoc