JavaOne Conference Trip Report

Database Connectivity with JDBC Technology

They are stressing a compatibility program via the email address jdbc-business@eng.sun.com.

JDBC is a foundation technology for the following software: embedded SQL, Enterprise JavaBeans and Java Blend. JDBC is a call-level API that provides connection, submission and results processing methods. SQL can be handled as either a simple statement (normal way), prepared statement (for multiple times, which can contain input parameters), and callable statement (when you need output parameters or stored procedures).

The returned result from a query is called a ResultSet. This provides a dynamic API where you can discover the types of the data inside.

A demo of InterSolv followed - they said they really liked JBuilder.

The spec for JDBC V. 2.0 is now available on the net; comments are welcome. This is the version due with JDK V. 1.2 which is in beta 3 version now. JDBC V. 2.0 changes include:

• ResultSet enhancements
• New data types:
  • blob, clob, array, reference, structured, distinct
  • Java programmed classes can be stored and loaded
  • Mapping of data is customizable per connection by extending the get/setObject methods
• Standard extensions to JDBC:
  • RowSet component
    • This is a JavaBean component
    • Properties include command, data source and maximum rows
    • Events are defined for cursor movement and update
    • Multiple cursors are supported
    • Caching is provided, and you can operate disconnected (if you reconnect, updates will be made if the data hasn't changed in the modified columns)
    • The information can be serialized and passed around
  • Distributed transactions
    • XA-style hooks
    • XAResource interface
  • Scrollable ResultSets:
    • static, dynamic and keyset
    • forward and backward traversal
    • absolute and relative addressing
  • Updating ResultSets:
    • readonly, locking, optomistic
    • Direct update, delete, insert
    • Alternative to positioned update and delete

There have been performance improvements added for JDBC V. 2.0. First, updates can now be batched. There are added performance hints for pre-fetch and way-to-use (e.g. array fetching). And, they've added connection pooling, which is most useful for server-side Java.

JDBC 2.0 is managed via JNDI services. There is a new DataSource interface/extension that provides properties and a factory to create connections.

You can get the source for the InterSolv demo at the JavaOne website.