<package>com.bs.amg.test</package>
	<access>PROPERTY</access>
	<sequence-generator name="PK_FILES" sequence-name="FILES_ID_SEQ" allocation-size="1" initial-value="1" />
	<sequence-generator name="PK_COLUMNS" sequence-name="COLUMNS_ID_SEQ" allocation-size="1" initial-value="1" />
	<entity class="com.bs.amg.test.File" name="File" metadata-complete="false">
		<table name="FILES"/>
		<attributes>
			<id name="id">
				<column name="ID" nullable="false"/>
				<generated-value strategy="SEQUENCE" generator="PK_FILES" />
			</id>
			<basic name="URI" optional="true">
				<column name="URI"/>
			</basic>
			<basic name="delimiter" optional="true">
				<column name="DELIMITER"/>
			</basic>
			<basic name="title">
				<column name="IS_TITLE"/>
			</basic>
			<basic name="colCount">
				<column name="COL_COUNT"/>
			</basic>
			<one-to-many name="columns" mapped-by="file" target-entity="com.bs.amg.test.FileColumn" fetch="LAZY">
				<cascade>
					<cascade-refresh/>
				</cascade>
			</one-to-many>
		</attributes>
	</entity>
	<entity class="com.bs.amg.test.FileColumn" name="FileColumn" metadata-complete="false">
		<table name="COLUMNS"/>
		<attributes>
			<id name="id">
				<column name="ID" nullable="false"/>
				<generated-value strategy="SEQUENCE" generator="PK_COLUMNS"/>
			</id>
			<basic name="position" optional="true">
				<column name="POSITION"/>
			</basic>
			<basic name="title" optional="true">
				<column name="TITLE"/>
			</basic>
			<basic name="type" optional="true">
				<column name="TYPE"/>
			</basic>
			<many-to-one name="file" optional="true" fetch="LAZY" target-entity="com.bs.amg.test.File">
				<cascade>
					<cascade-refresh/>
				</cascade>
			</many-to-one>
		</attributes>
	</entity>

@PersistenceContext( unitName = "manager1")
EntityManager entityManager;

private File file;

private File save( File file ) throws IOException {
	entityManager.persist( file );

	return file;
}

public boolean createFile( String URI ) throws IOException {
	file = File.getInstance( URI ); // происходит правильное заполнение полей File-а
	file = save( file );

	return true;
}

Caused by: org.hibernate.PersistentObjectException: detached entity passed to persist: com.bs.amg.test.persistence.File
	at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:141) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
	at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:78) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
	at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:725) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
	at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:701) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
	at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:705) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
	at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:853) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
	... 60 more

File.GetInstance()