Self-recursive Entity relation as part of the compound key will continue to throw SatckOverflow exception with current implementation. I was only partially successful in plugging that error by changing OpenJPA implementation. Because even if the recursive loop is terminated while resolving metadata -- OpenJPA enhanced code does not fully account for self-recursive composite keys. Hence the test fails later within enhanced code to create an application identity. Making changes to enhanced code has a more sever impact across the board.
At this point, a tree-structured domain model has to live with simple keys -- imo. CASERO Jaime wrote: > > After changing the OwnerId class definition as you suggested. > The same exception is thrown again: > > java.lang.StackOverflowError > at > org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepositor > y.java:277) > at > org.apache.openjpa.meta.MetaDataRepository.resolveMeta(MetaDataRepositor > y.java:528) > at > org.apache.openjpa.meta.MetaDataRepository.resolve(MetaDataRepository.ja > va:488) > at > org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepositor > y.java:290) > at > org.apache.openjpa.meta.MetaDataRepository.resolveMeta(MetaDataRepositor > y.java:557) > at > org.apache.openjpa.meta.MetaDataRepository.resolve(MetaDataRepository.ja > va:488) > ) > > Any ideas? > > I'm worry about the "equals" and "hascode" methods overridings > of both the Owner and OwnerId (they have a very recursive behavior). > Could be this issue affecting the metadata resolving?. I guess "equals" > and "hasCode" are only important in runtime. > > -----Original Message----- > From: Pinaki Poddar [mailto:[EMAIL PROTECTED] > Sent: Friday, July 20, 2007 10:05 PM > To: [email protected] > Subject: Re: Mapping tree structures or self-referencing foreign-Keys > > > 1. Owner has a compound key. The key is comprised of two fields: > @Id protected String label; > @Id protected Owner owner; > > 2. Owner says that its compound key class is represented by > OwnerId.class > @IdClass(com.covansys.routingengine.ifc.jpa.OwnerId.class) > public class Owner > > 3. The rule to define the Idclass OwnerId is > a) it must declare all the key fields of Owner > and you declared 'label' and 'owner' > b) the type of the Idclass' fields must be the same as the original > fields > *except* for relation field. > for relation field R, the type of Idclass' field must be the R's > identity > class type. > Here for field 'owner' is a relation field i.e. R=Owner. Id type of R > is > OwnerId. So OwnerId.owner should be of type OwnerId. Resulting into > public class OwnerId { > public String label; > public OwnerId owner; > > ====================================================================== > > I do not know the details of your domain model that requires such > identity > scheme. I would suggest that design a simpler Tree structure like this: > > @Entity > public class Node { > @Id > private long; > @ManyToOne > private Node parent; > @OneToMany(mappedBy="parent", cascade=CascadeType.ALL) > private List<Node> children; > } > > > > > > CASERO Jaime wrote: >> >> Hi all, >> >> >> >> I'm trying to persist a tree structure. Here class A >> references several A's (as his children -> OneToMany), and one A(p) > (as >> his parent -> ManyToOne). When JPA is parsing my metadata a >> "StackOverflowError" exception is thrown. Seems to be the typical >> recursive problem because of the self-referencing foreign key (=a >> foreign key to the same table) created. >> >> >> >> I haven't seend any referente in the manual to this >> scenario. >> >> >> >> Has anyone try this before? Is this feature supported by >> openJPA/JPA? Should i try one of the standard sql approches > ("Adjacency >> List Model", "The Path Enumeration Model", "Nested Set Model of >> Hierarchies"..), or is completely unsupported? >> >> >> >> Thanks in advance >> >> >> >> >> >> Here is the class, and its corresponding Id class: >> >> >> >> /////Owner/////// >> >> package com.covansys.routingengine.functionalcore; >> >> >> >> import javax.persistence.*; >> >> >> >> import org.apache.openjpa.persistence.ElementDependent; >> >> >> >> import com.covansys.routingengine.ifc.jpa.ScreeningElementId; >> >> >> >> import java.util.*; >> >> >> >> @Entity >> >> @IdClass(com.covansys.routingengine.ifc.jpa.OwnerId.class) >> >> public class Owner extends OwnerEntity implements Comparable >> >> { >> >> >> >> @Id >> >> protected String label; >> >> >> >> @Id >> >> @ManyToOne >> >> protected Owner owner; >> >> /** >> >> * <p> >> >> * This function returns the value of the owner member >> >> * </p> >> >> * @return owner, Owner object which contains the owner >> member value >> >> */ >> >> public Owner getOwner() >> >> { >> >> return owner; >> >> } >> >> >> >> >> >> /** >> >> * <p> >> >> * This function sets the owner value to the value of the >> owner passed >> >> * as argument. If the value of the targetOwner is null > then >> it sets its >> >> * value to the same owner. >> >> * </p> >> >> * @param o Owner object to be set as owner >> >> */ >> >> public void setOwner(Owner o) >> >> { >> >> owner = o; >> >> } >> >> >> >> >> >> >> >> >> >> >> >> /** >> >> * <p> >> >> * This function returns the value of the label member >> >> * </p> >> >> * @return label, String which contains the label member >> value >> >> */ >> >> public String getLabel() >> >> { >> >> return label; >> >> } >> >> >> >> >> >> /** >> >> * <p> >> >> * This function sets the value of the label member to the >> value >> >> * of the String passed as argument >> >> * </p> >> >> * @param l String to be set as label >> >> */ >> >> public void setLabel(String l) >> >> { >> >> label = l; >> >> } >> >> >> >> @ElementDependent >> >> @OneToMany(mappedBy="owner", cascade={CascadeType.ALL}) >> >> private Set<Owner> children; >> >> >> >> >> >> @Basic >> >> private String tag; >> >> >> >> >> >> >> >> >> >> public Owner() >> >> { >> >> children = new HashSet<Owner>(); >> >> } >> >> >> >> public void setOwnerId(long id) >> >> { >> >> //ownerId= id; >> >> } >> >> >> >> public long getOwnerId() >> >> { >> >> //return ownerId; >> >> return 0; >> >> } >> >> >> >> public int compareTo(Object o) >> >> { >> >> if (o instanceof Owner) >> >> { >> >> Owner owner = (Owner)o; >> >> return >> getLabel().compareTo(owner.getLabel()); >> >> } else { >> >> //put behind >> >> return 1; >> >> } >> >> } >> >> >> >> >> >> >> >> >> >> /*public int hashCode() { >> >> return ((label == null) ? 0 : label.hashCode()) >> >> ^ ((owner == null) ? 0 : owner.hashCode()); >> >> } */ >> >> >> >> public boolean equals(Object o) >> >> { >> >> if (this == o) return true; >> >> if (o instanceof Owner) >> >> { >> >> Owner owner = (Owner)o; >> >> //return this.getOwner() == >> owner.getOwner() && getLabel().equals(owner.getLabel()); >> >> return >> getLabel().equals(owner.getLabel()); >> >> } else { >> >> return false; >> >> } >> >> } >> >> >> >> public boolean isChild(Owner o) >> >> { >> >> if (o == null ) >> >> { >> >> return false; >> >> } else { >> >> if (equals(o)) { >> >> return true; >> >> } else { >> >> boolean found = false; >> >> Iterator<Owner> it = >> children.iterator(); >> >> Owner child = null; >> >> while(it.hasNext() && >> !found) { >> >> child = >> it.next(); >> >> found = >> child.isChild(o); >> >> } >> >> return found; >> >> } >> >> } >> >> } >> >> >> >> >> >> public void setTag(String t) >> >> { >> >> tag = t; >> >> } >> >> >> >> public String getTag() >> >> { >> >> return tag; >> >> } >> >> >> >> public void addChild(Owner o) >> >> { >> >> children.add(o); >> >> o.setOwner(this); >> >> } >> >> public void removeChild(Owner o) >> >> { >> >> children.remove(o); >> >> } >> >> public void removeAllChildren() >> >> { >> >> for (int i = 0 ; i < children.size(); i ++) >> >> children.remove(i); >> >> } >> >> >> >> public Collection<Owner> getChildren() >> >> { >> >> return children; >> >> } >> >> >> >> >> >> public List<Owner> getAllChildren() >> >> { >> >> List<Owner> allChildren = new Vector<Owner>(); >> >> for(Owner oAux : children) >> >> { >> >> >> allChildren.addAll(oAux.getAllChildren()); >> >> } >> >> return allChildren; >> >> } >> >> >> >> public Owner searchChild(String label) throws > OwnerNotFound >> >> { >> >> Owner oAux = new Owner(); >> >> oAux.setLabel(label); >> >> return searchChild(oAux); >> >> } >> >> >> >> public Owner searchChildByTag(String t) throws > OwnerNotFound >> >> { >> >> if (t == null ) >> >> { >> >> throw new OwnerNotFound(); >> >> } else { >> >> if (t.equals(this.tag)) >> >> { >> >> return this; >> >> } else { >> >> boolean found = false; >> >> Iterator<Owner> it = >> children.iterator(); >> >> Owner child = null; >> >> Owner oAux = null; >> >> while(it.hasNext() && >> !found) >> >> { >> >> try >> >> { >> >> >> child = it.next(); >> >> >> oAux = child.searchChildByTag(t); >> >> >> found = true; >> >> } catch >> (Exception e) { >> >> > >> >> } >> >> } >> >> if (found) >> >> { >> >> return > oAux; >> >> } else { >> >> throw new >> OwnerNotFound(); >> >> } >> >> } >> >> } >> >> } >> >> >> >> public Owner searchChild(Owner o) throws OwnerNotFound >> >> { >> >> if (o == null ) >> >> { >> >> throw new OwnerNotFound(); >> >> } else { >> >> if (equals(o)) >> >> { >> >> return this; >> >> } else { >> >> boolean found = false; >> >> Iterator<Owner> it = >> children.iterator(); >> >> Owner child = null; >> >> Owner oAux = null; >> >> while(it.hasNext() && >> !found) >> >> { >> >> try >> >> { >> >> >> child = it.next(); >> >> >> oAux = child.searchChild(o); >> >> >> found = true; >> >> } catch >> (Exception e) { >> >> >> //this child don't have the owner, try with the next >> >> } >> >> } >> >> if (found) >> >> { >> >> return > oAux; >> >> } else { >> >> throw new >> OwnerNotFound(); >> >> } >> >> } >> >> } >> >> } >> >> >> >> } >> >> >> >> ////////end owner/////// >> >> >> >> >> >> >> >> //////////OwnerId////////// >> >> package com.covansys.routingengine.ifc.jpa; >> >> >> >> import java.util.List; >> >> >> >> import com.covansys.routingengine.functionalcore.Owner; >> >> >> >> >> >> public class OwnerId >> >> { >> >> public String label; >> >> public String owner; >> >> >> >> public boolean equals(Object other) { >> >> if (other == this) >> >> return true; >> >> if (!(other instanceof OwnerId)) >> >> return false; >> >> >> >> OwnerId mi = (OwnerId) other; >> >> return (label == mi.label >> >> || (label != null && label.equals(mi.label))) >> >> && (owner == mi.owner >> >> || (owner != null && owner.equals(mi.owner))); >> >> } >> >> public int hashCode() { >> >> return ((label == null) ? 0 : label.hashCode()) >> >> ^ ((owner == null) ? 0 : owner.hashCode()); >> >> } >> >> >> >> >> >> } >> >> /////////end ownerid///////// >> >> Confidentiality Statement: >> >> This message is intended only for the individual or entity to which it > is >> addressed. It may contain privileged, confidential information which > is >> exempt from disclosure under applicable laws. If you are not the > intended >> recipient, please note that you are strictly prohibited from > disseminating >> or distributing this information (other than to the intended > recipient) or >> copying this information. If you have received this communication in >> error, please notify us immediately by return email. >> ----------------------------- >> >> > > -- > View this message in context: > http://www.nabble.com/Mapping-tree-structures-or-self-referencing-foreig > n-Keys-tf4117022.html#a11715126 > Sent from the OpenJPA Users mailing list archive at Nabble.com. > > Confidentiality Statement: > > This message is intended only for the individual or entity to which it is > addressed. It may contain privileged, confidential information which is > exempt from disclosure under applicable laws. If you are not the intended > recipient, please note that you are strictly prohibited from disseminating > or distributing this information (other than to the intended recipient) or > copying this information. If you have received this communication in > error, please notify us immediately by return email. > ----------------------------- > > -- View this message in context: http://www.nabble.com/Mapping-tree-structures-or-self-referencing-foreign-Keys-tf4117022.html#a11748494 Sent from the OpenJPA Users mailing list archive at Nabble.com.
