IllegalArgumentException: cannot remove/save a detached entity

[Prashaant Sharma]

Hi,

I have 3 entities with relationships shown below.

Entity: MyA

	@Id
	@Column(name = "ID", nullable = false)
	@GeneratedValue(generator = "MY_SEQUENCE", strategy = SEQUENCE)
	private long id;

	@Column(name = "A_NAME", nullable = false, unique = true)
	private String name;

	@OneToOne(optional = false, fetch = EAGER, cascade = { ALL })
	@JoinColumn(name = "B_ID", referencedColumnName = "ID", nullable = false)
	private MyB b;

Entity: MyB

	@Id
	@Column(name = "ID", nullable = false)
	@GeneratedValue(generator = "MY_SEQUENCE", strategy = SEQUENCE)
	private long id;

	@Column(name = "B_NAME", nullable = false, unique = true)
	private String name;

	@OneToMany(fetch = EAGER, mappedBy = "myB", cascade = { ALL })
	private Set<MyC> myC;

Entity: MyC

	@Id
	@Column(name = "ID", nullable = false)
	@GeneratedValue(generator = "MY_SEQUENCE", strategy = SEQUENCE)
	private long id;

	@Column(name = "C_NAME", nullable = false, unique = true)
	private String name;

	@ManyToOne(optional = true)
	@JoinColumn(name = "B_ID", referencedColumnName = "ID", nullable = false)
	private MyB myB;

When removing already persisted MyA entity using below code, I am getting "java.lang.IllegalArgumentException: Removing a detached instance MyA" exception

public void removeMyA(MyA obj) {
    MyA obj = entityManager.find(MyA.class, obj.getId());
    entityManager.remove(obj);
    entityManager.flush();
}

Any help or pointers would be really helpful.
Thanks in advance

[Tejas Morabia]

A transfer object are usually detached. And detached object cannot be removed.
So i will suggest try to use merge before removing.
Try something like this

  
public void removeMyA(MyA obj) {  
    MyA obj = entityManager.merge(obj);  
    entityManager.remove(obj);  
    entityManager.flush();  
}  

 

I hope this helps.