I have entities User and GrantedRole that have a bidirectional one-to-many relation.
When I try to add a GrantedRole to the Set in User, there is no exception thrown, but when I debug the variables for the User and GrantedRole object have a description that reads
com.sun.jdi.InvocationException occurred invoking method.
The different fields for the variables can be read while debugging, but when I select the roles field in User or the user field in GrantedRole I get the same description as above. When I go into the Set of GrantedRole in user, I eventually find the following description:
Detail formatter error: An exception occurred: java.lang.StackOverflowError
My code:
public class User { private Set<GrantedRole> roles = new HashSet<GrantedRole>(); public User() { super(); } public User(String name, String password) { this.name = name; this.password = password; } @OneToMany(fetch = FetchType.EAGER, mappedBy = "user") public Set<GrantedRole> getRoles() { return roles; } public void setRoles(Set<GrantedRole> roles) { this.roles = roles; } // equals and hashCode are based on username // toString is based on all fields } public class GrantedRole { private user user; public GrantedRole() { super(); } public GrantedRole(User user, Role role, Organization organization) { this.user = user; this.role = role; this.organization = organization; } @ManyToOne @NotNull public User getUser() { return user; } public void setUser(User user) { this.user = user; } // equals and hashCode are based on all fields // toString was based on all fields, I've changed it to not include User. } public class Test { public void testStuff() { User user = new User("name"); GrantedRole role = new GrantedRole(user, "role"); //this sets the user field user.getRoles().add(role); //doesn't throw Exception, but debugging shows InvocationTargetException and StackOverflowException System.out.println(user.getRoles()); //throws StackOverflowException, as I would expect } } It was my understanding that I should be able to set up a bidirectional relation in this way. I read multiple tutorials, like this one
I left out some trivial code, if it is needed I will gladly provide it. I haven't made code to ensure that a GrantedRole with a reference to a User is referenced by that user in return, but I think that is not relevant for the problem I'm having.