org.hibernate.engine.jdbc.dialect.spi.DialectResolver#resolveDialect ( )源码实例Demo

@Override
public Long getNextID(final String sequenceName) {

    ReturningWork<Long> maxReturningWork = new ReturningWork<Long>() {
        @Override
        public Long execute(Connection connection) throws SQLException {
            DialectResolver dialectResolver = new StandardDialectResolver();
            Dialect dialect = dialectResolver.resolveDialect(getResolutionInfo(connection));
            PreparedStatement preparedStatement = null;
            ResultSet resultSet = null;
            try {
                preparedStatement = connection.prepareStatement(dialect.getSequenceNextValString(sequenceName));
                resultSet = preparedStatement.executeQuery();
                resultSet.next();
                return resultSet.getLong(1);
            } catch (SQLException e) {
                throw e;
            } finally {
                if (preparedStatement != null) {
                    preparedStatement.close();
                }
                if (resultSet != null) {
                    resultSet.close();
                }
            }

        }
    };

    Session session = (Session) entityManager.getDelegate();
    SessionFactory sessionFactory = session.getSessionFactory();

    Long maxRecord = sessionFactory.getCurrentSession().doReturningWork(maxReturningWork);
    return maxRecord;
}
 

@Override
public void createSequence(final String sequenceName) {

    if (sequenceExists(sequenceName)) {
        return;
    }
    Work work = new Work() {
        @Override
        public void execute(Connection connection) throws SQLException {
            DialectResolver dialectResolver = new StandardDialectResolver();
            Dialect dialect = dialectResolver.resolveDialect(getResolutionInfo(connection));
            PreparedStatement preparedStatement = null;
            ResultSet resultSet = null;
            try {
                preparedStatement = connection
                        .prepareStatement(dialect.getCreateSequenceStrings(sequenceName, 1, 1)[0]);
                preparedStatement.execute();
            } catch (SQLException e) {
                throw e;
            } finally {
                if (preparedStatement != null) {
                    preparedStatement.close();
                }
                if (resultSet != null) {
                    resultSet.close();
                }
            }

        }
    };

    Session session = (Session) entityManager.getDelegate();
    SessionFactory sessionFactory = session.getSessionFactory();
    sessionFactory.getCurrentSession().doWork(work);
}
 

@Override
public boolean sequenceExists(final String sequenceName) {
    ReturningWork<Boolean> work = new ReturningWork<Boolean>() {
        @Override
        public Boolean execute(Connection connection) throws SQLException {
            DialectResolver dialectResolver = new StandardDialectResolver();
            Dialect dialect = dialectResolver.resolveDialect(getResolutionInfo(connection));
            PreparedStatement preparedStatement = null;
            ResultSet resultSet = null;
            try {
                preparedStatement = connection.prepareStatement(dialect.getQuerySequencesString());
                resultSet = preparedStatement.executeQuery();
                while (resultSet.next()) {
                    if (sequenceName.equals(resultSet.getString(1))) {
                        return true;
                    }
                }
            } catch (SQLException e) {
                throw e;
            } finally {
                if (preparedStatement != null) {
                    preparedStatement.close();
                }
                if (resultSet != null) {
                    resultSet.close();
                }
            }
            return false;

        }
    };

    Session session = (Session) entityManager.getDelegate();
    SessionFactory sessionFactory = session.getSessionFactory();
    return sessionFactory.getCurrentSession().doReturningWork(work);
}
 

@Override
public void dropSequence(final String sequenceName) {

    Work work = new Work() {
        @Override
        public void execute(Connection connection) throws SQLException {
            DialectResolver dialectResolver = new StandardDialectResolver();
            Dialect dialect = dialectResolver.resolveDialect(getResolutionInfo(connection));
            PreparedStatement preparedStatement = null;
            ResultSet resultSet = null;
            try {
                preparedStatement = connection.prepareStatement(dialect.getDropSequenceStrings(sequenceName)[0]);
                preparedStatement.execute();
            } catch (SQLException e) {
                throw e;
            } finally {
                if (preparedStatement != null) {
                    preparedStatement.close();
                }
                if (resultSet != null) {
                    resultSet.close();
                }
            }

        }
    };

    Session session = (Session) entityManager.getDelegate();
    SessionFactory sessionFactory = session.getSessionFactory();
    sessionFactory.getCurrentSession().doWork(work);
}