C H A P T E R  15

Java in the Database

Java plays an important role in the application development space today. It has become increasingly popular over the years, because it is cross-platform, powerful, and easy to learn. Although Java development is not directly related to PL/SQL, it is important for a PL/SQL developer to learn a bit about Java since there are some major benefits to using it to perform database tasks. Integrating the two languages when you're building Oracle Database applications is a seamless effort. Oracle Database 11g contains JVM compatibility with Java 1.5, which includes substantial changes to the Java language, making it an even more complementary development platform. Also starting with Oracle 11g, the database includes a just-in-time compiler, which compiles Java bytecode into machine language instructions, making Java in the database run much faster. In 2010, Oracle acquired Sun Microsystems, so it now owns Java. This may help the database JVM compatibility remain in concert with the latest releases.

In this chapter, you will learn how to combine the power of PL/SQL development with Java code that is stored within the database. You will learn how to create stored procedures, functions, and triggers using the Java language. Running Java in the database is a substantial topic that has filled entire books, but in this chapter, we will focus only on using the Java types in conjunction with PL/SQL applications—which, after all, is the subject of this book. For complete documentation on using Java inside Oracle Database, please see the Oracle Java developers guide at http://download.oracle.com/docs/cd/E11882_01/java.112/e10588/toc.htm.