session.java

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	 * and return it as a newly persistent instance. Otherwise, the given instance
	 * does not become associated with the session.
	 * 
	 * @param object a persistent or transient instance with state to be copied
	 * @param id the identifier of the instance to copy to
	 * @return an updated persistent instance
	 */
	public Object saveOrUpdateCopy(Object object, Serializable id) throws HibernateException;
	
	/**
	 * Remove a persistent instance from the datastore. The argument may be
	 * an instance associated with the receiving <tt>Session</tt> or a transient
	 * instance with an identifier associated with existing persistent state.
	 *
	 * @param object the instance to be removed
	 * @throws HibernateException
	 */
	public void delete(Object object) throws HibernateException;
	
	/**
	 * Execute a query.
	 *
	 * @param query a query expressed in Hibernate's query language
	 * @return a distinct list of instances (or arrays of instances)
	 * @throws HibernateException
	 */
	public List find(String query) throws HibernateException;
			
	/**
	 * Execute a query with bind parameters.
	 *
	 * Bind a value to a "?" parameter in the query string.
	 *
	 * @param query the query string
	 * @param value a value to be bound to a "?" placeholder (JDBC IN parameter).
	 * @param type the Hibernate type of the value
	 * @see Hibernate for access to <tt>Type</tt> instances
	 * @return a distinct list of instances (or arrays of instances)
	 * @throws HibernateException
	 */
	public List find(String query, Object value, Type type) throws HibernateException;
	
	/**
	 * Execute a query with bind parameters.
	 *
	 * Binding an array of values to "?" parameters in the query string.
	 *
	 * @param query the query string
	 * @param values an array of values to be bound to the "?" placeholders (JDBC IN parameters).
	 * @param types an array of Hibernate types of the values
	 * @see Hibernate for access to <tt>Type</tt> instances
	 * @return a distinct list of instances
	 * @throws HibernateException
	 */
	public List find(String query, Object[] values, Type[] types) throws HibernateException;
	
	/**
	 * Execute a query and return the results in an iterator. If the query has multiple
	 * return values, values will be returned in an array of type <tt>Object[].</tt><br>
	 * <br>
	 * Entities returned as results are initialized on demand. The first SQL query returns
	 * identifiers only. So <tt>iterate()</tt> is usually a less efficient way to retrieve
	 * objects than <tt>find()</tt>.
	 *
	 * @param query the query string
	 * @return an iterator
	 * @throws HibernateException
	 */
	public Iterator iterate(String query) throws HibernateException;
	
	/**
	 * Execute a query and return the results in an iterator. Write the given value to "?"
	 * in the query string. If the query has multiple return values, values will be returned
	 * in an array of type <tt>Object[]</tt>.<br>
	 * <br>
	 * Entities returned as results are initialized on demand. The first SQL query returns
	 * identifiers only. So <tt>iterate()</tt> is usually a less efficient way to retrieve
	 * objects than <tt>find()</tt>.
	 *
	 * @param query the query string
	 * @param value a value to be witten to a "?" placeholder in the query string
	 * @param type the hibernate type of value
	 * @return an iterator
	 * @throws HibernateException
	 */
	public Iterator iterate(String query, Object value, Type type) throws HibernateException;
	
	/**
	 * Execute a query and return the results in an iterator. Write the given values to "?"
	 * in the query string. If the query has multiple return values, values will be returned
	 * in an array of type <tt>Object[]</tt>.<br>
	 * <br>
	 * Entities returned as results are initialized on demand. The first SQL query returns
	 * identifiers only. So <tt>iterate()</tt> is usually a less efficient way to retrieve
	 * objects than <tt>find()</tt>.
	 *
	 * @param query the query string
	 * @param values a list of values to be written to "?" placeholders in the query
	 * @param types a list of Hibernate types of the values
	 * @return an iterator
	 * @throws HibernateException
	 */
	public Iterator iterate(String query, Object[] values, Type[] types) throws HibernateException;
	
	/**
	 * Apply a filter to a persistent collection. A filter is a Hibernate query that may refer to
	 * <tt>this</tt>, the collection element. Filters allow efficient access to very large lazy
	 * collections. (Executing the filter does not initialize the collection.)
	 *
	 * @param collection a persistent collection to filter
	 * @param filter a filter query string
	 * @return Collection the resulting collection
	 * @throws HibernateException
	 */
	public Collection filter(Object collection, String filter) throws HibernateException;
	
	/**
	 * Apply a filter to a persistent collection. A filter is a Hibernate query that may refer to
	 * <tt>this</tt>, the collection element.
	 *
	 * @param collection a persistent collection to filter
	 * @param filter a filter query string
	 * @param value a value to be witten to a "?" placeholder in the query string
	 * @param type the hibernate type of value
	 * @return Collection
	 * @throws HibernateException
	 */
	public Collection filter(Object collection, String filter, Object value, Type type) throws HibernateException;
	
	/**
	 * Apply a filter to a persistent collection.
	 *
	 * Bind the given parameters to "?" placeholders. A filter is a Hibernate query that
	 * may refer to <tt>this</tt>, the collection element.
	 *
	 * @param collection a persistent collection to filter
	 * @param filter a filter query string
	 * @param values a list of values to be written to "?" placeholders in the query
	 * @param types a list of Hibernate types of the values
	 * @return Collection
	 * @throws HibernateException
	 */
	public Collection filter(Object collection, String filter, Object[] values, Type[] types) throws HibernateException;
	
	/**
	 * Delete all objects returned by the query. Return the number of objects deleted.
	 *
	 * @param query the query string
	 * @return the number of instances deleted
	 * @throws HibernateException
	 */
	public int delete(String query) throws HibernateException;
	
	/**
	 * Delete all objects returned by the query. Return the number of objects deleted.
	 *
	 * @param query the query string
	 * @param value a value to be witten to a "?" placeholder in the query string.
	 * @param type the hibernate type of value.
	 * @return the number of instances deleted
	 * @throws HibernateException
	 */
	public int delete(String query, Object value, Type type) throws HibernateException;
	
	/**
	 * Delete all objects returned by the query. Return the number of objects deleted.
	 *
	 * @param query the query string
	 * @param values a list of values to be written to "?" placeholders in the query.
	 * @param types a list of Hibernate types of the values
	 * @return the number of instances deleted
	 * @throws HibernateException
	 */
	public int delete(String query, Object[] values, Type[] types) throws HibernateException;
	
	/**
	 * Obtain the specified lock level upon the given object. This may be used to
	 * perform a version check (<tt>LockMode.READ</tt>), to upgrade to a pessimistic 
	 * lock (<tt>LockMode.UPGRADE</tt>), or to simply reassociate a transient instance 
	 * with a session (<tt>LockMode.NONE</tt>).
	 *
	 * @param object a persistent or transient instance
	 * @param lockMode the lock level
	 * @throws HibernateException
	 */
	public void lock(Object object, LockMode lockMode) throws HibernateException;
	
	/**
	 * Re-read the state of the given instance from the underlying database. It is
	 * inadvisable to use this to implement long-running sessions that span many
	 * business tasks. This method is, however, useful in certain special circumstances.
	 * For example
	 * <ul>
	 * <li>where a database trigger alters the object state upon insert or update
	 * <li>after executing direct SQL (eg. a mass update) in the same session
	 * <li>after inserting a <tt>Blob</tt> or <tt>Clob</tt>
	 * </ul>
	 *
	 * @param object a persistent or transient instance
	 * @throws HibernateException
	 */
	public void refresh(Object object) throws HibernateException;
	
	/**
	 * Re-read the state of the given instance from the underlying database, with
	 * the given <tt>LockMode</tt>. It is inadvisable to use this to implement 
	 * long-running sessions that span many business tasks. This method is, however, 
	 * useful in certain special circumstances.
	 *
	 * @param object a persistent or transient instance
	 * @param lockMode the lock mode to use
	 * @throws HibernateException
	 */
	public void refresh(Object object, LockMode lockMode) throws HibernateException;
	
	/**
	 * Determine the current lock mode of the given object.
	 *
	 * @param object a persistent instance
	 * @return the current lock mode
	 * @throws HibernateException
	 */
	public LockMode getCurrentLockMode(Object object) throws HibernateException;
	
	/**
	 * Begin a unit of work and return the associated <tt>Transaction</tt> object.
	 * If a new underlying transaction is required, begin the transaction. Otherwise
	 * continue the new work in the context of the existing underlying transaction.
	 * The class of the returned <tt>Transaction</tt> object is determined by the
	 * property <tt>hibernate.transaction_factory</tt>.
	 *
	 * @return a Transaction instance
	 * @throws HibernateException
	 * @see Transaction
	 */
	public Transaction beginTransaction() throws HibernateException;
	
	/**
	 * Create a new <tt>Criteria</tt> instance, for the given entity class.
	 * 
	 * @param persistentClass
	 * @return Criteria
	 */
	public Criteria createCriteria(Class persistentClass);
	
	/**
	 * Create a new instance of <tt>Query</tt> for the given query string.
	 *
	 * @param queryString a Hibernate query
	 * @return Query
	 * @throws HibernateException
	 */
	public Query createQuery(String queryString) throws HibernateException;
	
	/**
	 * Create a new instance of <tt>Query</tt> for the given collection and filter string.
	 *
	 * @param collection a persistent collection
	 * @param queryString a Hibernate query
	 * @return Query
	 * @throws HibernateException
	 */
	public Query createFilter(Object collection, String queryString) throws HibernateException;
	
	/**
	 * Obtain an instance of <tt>Query</tt> for a named query string defined in the
	 * mapping file.
	 *
	 * @param queryName the name of a query defined externally
	 * @return Query
	 * @throws HibernateException
	 */
	public Query getNamedQuery(String queryName) throws HibernateException;

	/**
	 * Create a new instance of <tt>Query</tt> for the given SQL string.
	 * 
	 * @param sql a query expressed in SQL
	 * @param returnAlias a table alias that appears inside <tt>{}</tt> in the SQL string
	 * @param returnClass the returned persistent class
	 */
	public Query createSQLQuery(String sql, String returnAlias, Class returnClass);
	/**
	 * Create a new instance of <tt>Query</tt> for the given SQL string.
	 * 
	 * @param sql a query expressed in SQL
	 * @param returnAliases an array of table aliases that appear inside <tt>{}</tt> in the SQL string
	 * @param returnClasses the returned persistent classes
	 */
	public Query createSQLQuery(String sql, String[] returnAliases, Class[] returnClasses);
	
	/**
	 * Completely clear the session. Evict all loaded instances and cancel all pending
	 * saves, updates and deletions. Do not close open iterators or instances of
	 * <tt>ScrollableResults</tt>.
	 */
	public void clear();
	
	/**
	 * Return the persistent instance of the given entity class with the given identifier,
	 * or null if there is no such persistent instance. (If the instance, or a proxy for the
	 * instance, is already associated with the session, return that instance or proxy.)
	 * 
	 * @param clazz a persistent class
	 * @param id an identifier
	 * @return a persistent instance or null
	 * @throws HibernateException
	 */
	public Object get(Class clazz, Serializable id) throws HibernateException;

	/**
	 * Return the persistent instance of the given entity class with the given identifier,
	 * or null if there is no such persistent instance. Obtain the specified lock mode
	 * if the instance exists.
	 * 
	 * @param clazz a persistent class
	 * @param id an identifier
	 * @param lockMode the lock mode
	 * @return a persistent instance or null
	 * @throws HibernateException
	 */
	public Object get(Class clazz, Serializable id, LockMode lockMode) throws HibernateException;
	
}