package apusic.myshop.product.ejb;public class ProductPK implements java.io.Serializable {  public String productId;  public ProductPK() { }  public ProductPK(String productId) {    this.productId = productId;  }
   public String toString() {    	return String.valueOf(productId);    }   public boolean equals(Object obj) {	    if (obj != null && obj instanceof ProductPK)	        return productId == ((ProductPK)obj).productId;    	return false;   }   public int hashCode() {    	return productId.hashCode();   }    }