here is the answer of the question.
The JDBC API is a standard that allows Java applications to perform operations against permanent storage sources, The JDBC is a pure Java API used to execute SQL statements. It provides a set of classes and interfaces that can be used by developers to write database applications.
The steps needed to execute a SQL query using JDBC:
Loading a database driver.
System.out.println( ?Unable to load the driver class!? );
Creating a oracle jdbc Connection.
Creating a jdbc Statement object.
Executing a SQL statement.