Spring DAO JDBC

Motivation

• DAO : Understand what Data Access Objects are and why one should use them.
  
• Reduction of the boilerplate code : Demonstrate typical rich JDBC try/catch usage in opposite to the lean JdbcTemplate.
  
• Template method pattern : Describe what 'template' in JdbcTemplate stands for. Identify GOF template method pattern.
  
• JdbcDaoSupport interface : Know that programmer provides only DataSource (usually injected via IOC container) in order to get JdbcTemplate. Understand that this is convenient.
  
• SQL exceptions : Know that standard SQLException descendants are not classified into a hierarchy and are inconvenient in general (in particular getNextException() method)
  
• Additional abstraction layer : Identify additional layer of abstraction provided by Spring via SQL operations mappings
  

Exceptions

• Spring DataAccessException hierarchy - Identify the hierarchy of Spring data access exception.
• Particular Spring data access exceptions - Describe all the descendants of the DataAccessException. Identify situations in which each exception can be thrown.
• SQLExceptionTranslator - Understand how Spring translates various SQL exceptions into its own hierarchy, particularly how error codes of standard DBMSs are transformed into the exceptions.

DataSource

• Dependency Injection - Demonstrate various techniques of injecting DataSource into a JdbcTemplate.
• Various DataSources - Recognize when (and how to) use DataSources provided with Spring (such as DriverManagerDataSource, SingleConnectionDataSource, AbstractDataSource and so forth).
• Transactions - Identify how to manage transactions using Spring JDBC DAO.
• Connections in general - Anything else connected directly with the topic of JDBC connection management in Spring JDBC DAO.

Basic use of JdbcTemplate

• General information - Understand that JdbcTemplate is thread-safe and stateless. Describe that JdbcTemplate is usually injected into DAO beans as a singleton using Spring IOC container.
• Queries - Recognize purpose of the RowMapper and RowCallBackHandler. Demonstrate usage of the JdbcTemplate convenience methods queryForXXX. Demonstrate usage of various overloaded versions of the query() method (both parametrized and not parametrized).
• Updates - Identify proper usage of methods modifying data, particularly update(), execute() and batchUpdate().

Advanced use of JdbcTemplate

• Stored procedures - Demonstrate how stored procedures can be called using execute() method. Demonstrate dealing with the both input and output parameters.
• JdbcTemplate wrappers - Understand that JdbcTemplate wrappers are thread-safe. Know that classes implementing SimpleJdbcOperations interface (like SimpleJdbcTemplate) are convenient to use with Java >= 1.5. Identify other JdbcWrappers. Describe purposes of interfaces implemented by JdbcTemplate wrappers.
• JdbcTemplate interfaces - Know the purpose of interfaces used by JdbcTemplate, such as PreparedStatementCreator, PreparedStatementSetter, BatchPreparedStatementSetter or SqlProvider.
• LOB support - Demonstrate how to use LobHandler in order to deal with both BLOBs and CLOBs.

SQL operations mapping

• Common operations - Demonstrate usage of classes mapping common SQL operation, such as SqlUpdate, SqlQuery or UpdatableSqlQuery.
• Stored procedures - Demonstrate usage of classes mapping SQL procedures, such as StoredProcedure or SqlFunction.

Misc

• Keys generators (like DataFieldMaxValueIncrementer).
• Performance issues.
• Integration of Spring JDBC with the application server.
• JDBC vs ORM considerations.
• Anything else connected with the topic what does not fit into the other categories (please note that Spring ORM is not a part of this exam).