Given the following tree-like structure…
{code:java}@Entity
class Node {
@Id
String id;
@ManyToOne
Node parent;
@OneToMany(mappedBy = "parent", cascade = CascadeType.ALL, orphanRemoval = true)
Set<Node> children;
}{code}
… I’d like to be able freely move children between parents. I can easily do that when all entities involved in such transaction (2 parents and 1 child) are already persistent. It’s impossible however to insert new (transient) node “between” two existing nodes.
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I’m unable to make
{noformat}a
└── b{noformat}
become
{noformat}a
└── x
└── b{noformat}
if x is transient, as Hibernate deletes b.
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Adding {{x}} in between {{a}} and {{b}} involves 2 steps:
# removing {{b}} from {{a.children}}
# adding {{b}} to {{x.children}}
I suppose that step 1. makes Hibernate to mark {{b}} for deletion. Step 2. should somehow undo this - and it does, but only when {{x}} is already managed (and so is {{x.children}} collection). It’s worth noting that {{x}} becomes managed in the very same transaction because of {{CASCADE.ALL}} on {{a.children}}. I even tried to explicitly call {{persist(x)}} but it doesn't change anything - {{b}} is being deleted anyway.
This looks like a bug.
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I've created SSCCE:
{noformat}git clonehttps://github.com/perceptron8/orphan-removal
cd orphan-removal
mvn test{noformat}
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Please let me know if I can help somehow. |
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