jdotemplate.java

一个关于Spring框架的示例应用程序,简单使用,可以参考.

	}


	//-------------------------------------------------------------------------
	// Convenience methods for load, save, delete
	//-------------------------------------------------------------------------

	public Object getObjectById(final Serializable objectId) throws DataAccessException {
		return execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				return pm.getObjectById(objectId, true);
			}
		});
	}

	public Object getObjectById(final Class entityClass, final Serializable idValue) throws DataAccessException {
		return execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				Object oid = pm.newObjectIdInstance(entityClass, idValue.toString());
				return pm.getObjectById(oid, true);
			}
		});
	}

	public void evict(final Object entity) throws DataAccessException {
		execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				pm.evict(entity);
				return null;
			}
		});
	}

	public void evictAll() throws DataAccessException {
		execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				pm.evictAll();
				return null;
			}
		});
	}

	public void refresh(final Object entity) throws DataAccessException {
		execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				pm.refresh(entity);
				return null;
			}
		});
	}

	public void refreshAll() throws DataAccessException {
		execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				pm.refreshAll();
				return null;
			}
		});
	}

	public void makePersistent(final Object entity) throws DataAccessException {
		execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				pm.makePersistent(entity);
				return null;
			}
		});
	}

	public void deletePersistent(final Object entity) throws DataAccessException {
		execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				pm.deletePersistent(entity);
				return null;
			}
		});
	}

	public void deletePersistentAll(final Collection entities) throws DataAccessException {
		execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				pm.deletePersistentAll(entities);
				return null;
			}
		});
	}

	public void flush() throws DataAccessException {
		execute(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				getJdoDialect().flush(pm);
				return null;
			}
		});
	}


	//-------------------------------------------------------------------------
	// Convenience finder methods
	//-------------------------------------------------------------------------

	public Collection find(Class entityClass) throws DataAccessException {
		return find(entityClass, null, null);
	}

	public Collection find(Class entityClass, String filter) throws DataAccessException {
		return find(entityClass, filter, null);
	}

	public Collection find(final Class entityClass, final String filter, final String ordering)
			throws DataAccessException {
		return executeFind(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				Query query = (filter != null ? pm.newQuery(entityClass, filter) : pm.newQuery(entityClass));
				prepareQuery(query);
				if (ordering != null) {
					query.setOrdering(ordering);
				}
				return query.execute();
			}
		});
	}

	public Collection find(Class entityClass, String filter, String parameters, Object[] values)
			throws DataAccessException {
		return find(entityClass, filter, parameters, values, null);
	}

	public Collection find(
			final Class entityClass, final String filter, final String parameters, final Object[] values,
			final String ordering) throws DataAccessException {
		return executeFind(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				Query query = pm.newQuery(entityClass, filter);
				prepareQuery(query);
				query.declareParameters(parameters);
				if (ordering != null) {
					query.setOrdering(ordering);
				}
				return query.executeWithArray(values);
			}
		});
	}

	public Collection find(Class entityClass, String filter, String parameters, Map values)
			throws DataAccessException {
		return find(entityClass, filter, parameters, values, null);
	}

	public Collection find(
			final Class entityClass, final String filter, final String parameters, final Map values,
			final String ordering) throws DataAccessException {
		return executeFind(new JdoCallback() {
			public Object doInJdo(PersistenceManager pm) throws JDOException {
				Query query = pm.newQuery(entityClass, filter);
				prepareQuery(query);
				query.declareParameters(parameters);
				if (ordering != null) {
					query.setOrdering(ordering);
				}
				return query.executeWithMap(values);
			}
		});
	}


	/**
	 * Prepare the given JDO query object. To be used within a JdoCallback.
	 * Applies a transaction timeout, if any. If you don't use such timeouts,
	 * the call is a no-op.
	 * <p>In general, prefer a proxied PersistenceManager instead, which will
	 * automatically apply the transaction timeout (through the use of a special
	 * PersistenceManager proxy). You need to set the "exposeNativePersistenceManager"
	 * property to "false" to activate this. Note that you won't be able to cast
	 * to a vendor-specific JDO PersistenceManager class anymore then.
	 * @param query the JDO query object
	 * @throws JDOException if the query could not be properly prepared
	 * @see JdoCallback#doInJdo
	 * @see PersistenceManagerFactoryUtils#applyTransactionTimeout
	 * @see #setExposeNativePersistenceManager
	 */
	public void prepareQuery(Query query) throws JDOException {
		PersistenceManagerFactoryUtils.applyTransactionTimeout(
				query, getPersistenceManagerFactory(), getJdoDialect());
	}


	/**
	 * Invocation handler that suppresses close calls on JDO PersistenceManagers.
	 * Also prepares returned Query and Criteria objects.
	 * @see javax.jdo.PersistenceManager#close
	 */
	private class CloseSuppressingInvocationHandler implements InvocationHandler {

		private static final String PERSISTENCE_MANAGER_CLOSE_METHOD_NAME = "close";

		private final PersistenceManager target;

		public CloseSuppressingInvocationHandler(PersistenceManager target) {
			this.target = target;
		}

		public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
			// Handle close method: suppress, not valid.
			if (method.getName().equals(PERSISTENCE_MANAGER_CLOSE_METHOD_NAME)) {
				return null;
			}

			// Invoke method on target connection.
			try {
				Object retVal = method.invoke(this.target, args);

				// If return value is a JDO Query object, apply transaction timeout.
				if (retVal instanceof Query) {
					prepareQuery(((Query) retVal));
				}

				return retVal;
			}
			catch (InvocationTargetException ex) {
				throw ex.getTargetException();
			}
		}
	}

}