JavaServer Pages, 3rd Edition

JDBC Basics

The JDBC API is a set of classes and interfaces that allows a Java application to send SQL statements to a database in a vendor-independent way. The API consists mostly of interfaces that define the methods you use in your program. Database engine vendors and third parties provide implementations of these interfaces for a specific database engine; such an implementation is called a JDBC driver. This allows you to develop your program in a database-independent way and connect to a specific database engine by plugging in the appropriate JDBC driver at deployment time. There are JDBC drivers for most database engines on the market, both commercial and open source. If you can’t get one from your vendor, check out Sun’s list of third-party drivers at http://industry.java.sun.com/products/jdbc/drivers.

Figure 24-1 shows how the main interfaces and classes are related.

Figure 24-1. Main JDBC interfaces and classes

All JDBC core classes and interfaces belong to the java.sql package. Of the types shown in Figure 24-1, only the DriverManager is a class (part of the standard J2SE package); the rest are interfaces implemented by each unique JDBC driver.

The Driver implementation is the entry point to all the other interface implementations. When the Driver is loaded, it register itself with the DriverManager. When the JDBC application needs a connection to a database, it asks the ...