Storing a jpa entity where only the timestamp changes results in updates rather than inserts (desire
- by David Schlenk
I have a JPA entity that stores a fk id, a boolean and a timestamp:
@Entity
public class ChannelInUse implements Serializable {
@Id
@GeneratedValue
private Long id;
@ManyToOne
@JoinColumn(nullable = false)
private Channel channel;
private boolean inUse = false;
@Temporal(TemporalType.TIMESTAMP)
private Date inUseAt = new Date();
...
}
I want every new instance of this entity to result in a new row in the table. For whatever reason no matter what I do it always results in the row getting updated with a new timestamp value rather than creating a new row. Even tried to just use a native query to run an insert but channel's ID wasn't populated yet so I gave up on that. I've tried using an embedded id class consisting of channel.getId and inUseAt. My equals and hashcode for are:
public boolean equals(Object obj){
if(this == obj)
return true;
if(!(obj instanceof ChannelInUse))
return false;
ChannelInUse ciu = (ChannelInUse) obj;
return ( (this.inUseAt == null ? ciu.inUseAt == null : this.inUseAt.equals(ciu.inUseAt))
&& (this.inUse == ciu.inUse)
&& (this.channel == null ? ciu.channel == null : this.channel.equals(ciu.channel))
);
}
/**
* hashcode generated from at, channel and inUse properties.
*/
public int hashCode(){
int hash = 1;
hash = hash * 31 + (this.inUseAt == null ? 0 : this.inUseAt.hashCode());
hash = hash * 31 + (this.channel == null ? 0 : this.channel.hashCode());
if(inUse)
hash = hash * 31 + 1;
else
hash = hash * 31 + 0;
return hash;
}
}
I've tried using hibernate's Entity annotation with mutable=false. I'm probably just not understanding what makes an entity unique or something. Hit the google pretty hard but can't figure this one out.
