谷歌应用引擎的 ORM (java)

Question

我开发了谷歌端点 API 并使用 JDBC 访问云 sql 数据库。现在我想使用 ORM 工具来访问云 sql 数据库。 那么谷歌应用引擎支持哪些ORM工具而不是JDO和JPA？ 我的意思是，hibernate 支持 GAE 吗？

Answer 1

是的，Hibernate works with GAE Cloud SQL。

Answer 2

是的，Google App Engine 支持 Hibernate ORM 与 Google Cloud SQL 的结合。 我们在几乎所有的 Google App Engine 项目中都使用这种组合，有时甚至使用连接池；

Can i use HikariCP on Google App Engine

Cloud SQL 甚至可以在开发过程中使用；

Using Google Cloud SQL during Java appengine development (instead of local MySQL instance)

对于 Hibernate 连接，我们实现了自己的 ConnectionProvider（我从 appengine-java-connection-pool 得到这个想法）。在persistence.xml中

使用 BasicConnectionProvider；

public class BasicConnectionProvider implements ConnectionProvider, Configurable, Stoppable
{
    private static final long serialVersionUID = 5535849343546193022L;
    private static final org.jboss.logging.Logger LOGGER = org.jboss.logging.Logger.getLogger(com.project.server.hibernate.BasicConnectionProvider.class);
    private DriverManagerDataSource mDriverManagerDataSource = null;

    private int mConnectionCount;

    // *************************************************************************
    // Configurable
    // *************************************************************************

    @SuppressWarnings("rawtypes")
    @Override
    public void configure(Map pProperties) throws HibernateException
    {
        try
        {
            LOGGER.debug("Configuring DataSource");

            DriverManagerDataSource lDriverManagerDataSource = new DriverManagerDataSource();

            if (SystemProperty.environment.value() == SystemProperty.Environment.Value.Production)
            {
                lDriverManagerDataSource.setDriverClassName("com.mysql.jdbc.GoogleDriver");
                lDriverManagerDataSource.setUrl("jdbc:google:mysql://appengine-id:europe-west1:project/project");
            }
            else
            {
                lDriverManagerDataSource.setDriverClassName("com.mysql.jdbc.Driver");
                lDriverManagerDataSource.setUrl("jdbc:mysql://localhost:3306/project");
            }

            lDriverManagerDataSource.setUsername("root");
            lDriverManagerDataSource.setPassword("password");

            Properties lProperties = loadConfiguration(pProperties);

            lProperties.put("useSSL", "false");
            lProperties.put("cachePrepStmts", "true");
            lProperties.put("useServerPrepStmts", "true");
            lProperties.put("prepStmtCacheSize", "500");
            lProperties.put("prepStmtCacheSqlLimit", "2048");

            lDriverManagerDataSource.setConnectionProperties(lProperties);

            setDriverManagerDataSource(lDriverManagerDataSource);

            mConnectionCount = 0;
        }
        catch (Exception e)
        {
            throw new HibernateException(e);
        }

        LOGGER.debug("DataSource Configured");
    }

    public static Properties loadConfiguration(Map props)
    {
        Properties lProperties = new Properties();

        copyProperty(AvailableSettings.ISOLATION, props, "transactionIsolation", lProperties);
        copyProperty(AvailableSettings.AUTOCOMMIT, props, "autoCommit", lProperties);
        copyProperty(AvailableSettings.DRIVER, props, "driverClassName", lProperties);
        copyProperty(AvailableSettings.URL, props, "jdbcUrl", lProperties);
        copyProperty(AvailableSettings.USER, props, "username", lProperties);
        copyProperty(AvailableSettings.PASS, props, "password", lProperties);

        return lProperties;
    }

    @SuppressWarnings("rawtypes")
    private static void copyProperty(String srcKey, Map src, String dstKey, Properties dst)
    {
        if (src.containsKey(srcKey))
        {
            dst.setProperty(dstKey, (String) src.get(srcKey));
        }
    }

    // *************************************************************************
    // ConnectionProvider
    // *************************************************************************

    @Override
    public Connection getConnection() throws SQLException
    {
        Connection lConnection = null;

        if (mDriverManagerDataSource != null)
        {
            lConnection = mDriverManagerDataSource.getConnection();
        }

        mConnectionCount++;
        return lConnection;
    }

    @Override
    public void closeConnection(Connection pConnection) throws SQLException
    {
        mConnectionCount--;
        pConnection.close();
    }

    @Override
    public boolean supportsAggressiveRelease()
    {
        return false;
    }

    @Override
    @SuppressWarnings("rawtypes")
    public boolean isUnwrappableAs(Class unwrapType)
    {
        return ConnectionProvider.class.equals(unwrapType)
                || com.project.server.hibernate.BasicConnectionProvider.class.isAssignableFrom(unwrapType)
                || DataSource.class.isAssignableFrom(unwrapType);
    }

    @Override
    @SuppressWarnings("unchecked")
    public <T> T unwrap(Class<T> unwrapType)
    {
        if (ConnectionProvider.class.equals(unwrapType) ||
                com.project.server.hibernate.BasicConnectionProvider.class.isAssignableFrom(unwrapType))
        {
            return (T) this;
        }
        else if (DataSource.class.isAssignableFrom(unwrapType))
        {
            return (T) mDriverManagerDataSource;
        }
        else
        {
            throw new UnknownUnwrapTypeException(unwrapType);
        }
    }

    // *************************************************************************
    // Stoppable
    // *************************************************************************

    @Override
    public void stop()
    {

    }

    public DriverManagerDataSource getDriverManagerDataSource()
    {
        return mDriverManagerDataSource;
    }

    public void setDriverManagerDataSource(DriverManagerDataSource pDriverManagerDataSource)
    {
        mDriverManagerDataSource = pDriverManagerDataSource;
    }
}