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copied!<p>First, let's remind the various states of an entity. From the JPA 1.0 specification (in section 3.2 Entity Instance’s Life Cycle):</p> <blockquote> <p>This section describes the EntityManager operations for managing an entity instance’s lifecycle. An entity instance may be characterized as being new, managed, detached, or removed.</p> <ul> <li>A <strong>new</strong> entity instance has <strong>no persistent identity</strong>, and is not yet associated with a persistence context.</li> <li>A <strong>managed</strong> entity instance is an instance <strong>with a persistent identity</strong> that is currently associated with a persistence context.</li> <li>A <strong>detached</strong> entity instance is an instance <strong>with a persistent identity</strong> that is not (or no longer) associated with a persistence context.</li> <li>A <strong>removed</strong> entity instance is an instance with a persistent identity, associated with a persistence context, that is scheduled for removal from the database.</li> </ul> </blockquote> <p>And a graphical illustration:</p> <p><img src="https://openjpa.apache.org/builds/1.0.2/apache-openjpa-1.0.2/docs/manual/img/jpa-state-transitions.png" alt="alt text"></p> <p>So, by definition, a detached entity has already been persisted, and I actually don't think that this is your real question. Now, if you want to know if an entity is <em>new</em> (i.e. doesn't have any persistent identity), what about this:</p> <pre><code>@Transient public boolean isNew() { return (this.id == null); } </code></pre>

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