Goalsof JAVA-JDBC

The JDBC API is a mature technology, having first been specified in January 1997. In
its initial release, the JDBC API focused on providing a basic call-level interface to
SQL databases. The JDBC 2.1 specification and the 2.0 Optional Package
specification then broadened the scope of the API to include support for more
advanced applications and for the features required by application servers to
manage use of the JDBC API on behalf of their applications.
The overall goal of the JDBC 3.0 specification is to “round out” the API by filling in
smaller areas of missing functionality. The following list outlines the goals and
design philosophy for the JDBC API in general and the JDBC 3.0 API in particular:
1. Fit into the J2EE and J2SE platforms
The JDBC API is a constituent technology of the Java platform. The JDBC 3.0 API
should be aligned with the overall direction of the Java 2 Enterprise Edition and
Java 2 Standard Edition platforms.
2. Be consistent with SQL99
The JDBC API provides programmatic access from applications written in the
Java programming language to standard SQL. At the time the JDBC 2.0 API was
in development, the SQL99 specification was a moving target. SQL99 is now a
published standard and includes features that are widely supported among
DBMS vendors as well as features that only a few vendors support. The intent of
the JDBC 3.0 API is to provide access to the subset of SQL99 features that are
likely to be widely supported within the next five years.
3. Consolidate predecessor specifications
This document incorporates content from three prior JDBC specifications to
provide a single standalone specification of the JDBC API.
4. Offer vendor-neutral access to common features
The JDBC API strives to provide high-bandwidth access to features commonly
supported across different vendor implementations. The goal is to provide a
degree of feature access comparable to what can be achieved by native
applications. However, the API must be general and flexible enough to allow for
a wide range of implementations.
5. Maintain the focus on SQL
The focus of the JDBC API has always been on accessing relational data from the
Java programming language. This continues to be true with the JDBC 3.0 API. The
JDBC 3.0 API does not preclude interacting with other technologies, including
XML, CORBA, or non-relational data, but the primary target will still be relational
data and SQL.
6. Provide a foundation for tools and higher-level APIs
The JDBC API presents a standard API to access a wide range of underlying data
sources or legacy systems. Implementation differences are made transparent
through JDBC API abstractions, making it a valuable target platform for tools
vendors who want to create portable tools and applications.
Because it is a “call-level” interface from the Java programming language to SQL,
the JDBC API is also suitable as a base layer for higher-level facilities such as EJB
2.0 container-managed persistence and SQLJ.
7. Keep it simple
The JDBC API is intended to be a simple-to-use, straightforward interface upon
which more complex entities can be built. This goal is achieved by defining many
compact, single-purpose methods instead of a smaller number of complex, multipurpose
ones with control flag parameters.
8. Enhance reliability, availability, and scalability
Reliability, availability, and scalability are the themes of the J2EE and J2SE
platforms, as well as the direction for future Java platforms. The JDBC 3.0 API
stays true to these themes by enhancing support in several areas, including
resource management, the reuse of prepared statements across logical
connections, and error handling.
9. Maintain backward compatibility with existing applications and drivers
Existing JDBC technology-enabled drivers (“JDBC drivers”) and the applications
that use them must continue to work in an implementation of the Java virtual
machine that supports the JDBC 3.0 API. Applications that use only features
defined in earlier releases of the JDBC API, excluding those that were deprecated
by JDBC 2.0, will not require changes to continue running. It should be
straightforward for existing applications to migrate to JDBC 3.0 technology.
10. Allow forward compatibility with Connectors
The Connector architecture defines a standard way to package and deploy a
resource adapter that allows a J2EE container to integrate its connection,
transaction, and security management with those of an external resource.
The JDBC 3.0 API provides the migration path for JDBC drivers to the Connector
architecture. It should be possible for vendors whose products use JDBC
technology to move incrementally towards implementing the Connector API. The
expectation is that these implementors will write “resource manager wrappers”
around their existing data source implementations so that they can be reused in a
Connector framework.
11. Specify requirements unambiguously
The requirements for JDBC compliance need to be unambiguous and easy to
identify. The JDBC 3.0 specification and the API documentation (Javadoc) will
clarify which features are required and which are optional.