Oracle PL/SQL Programming, 6th Edition

Chapter 27. Calling Java from PL/SQL

The Java language, originally designed and promoted by Sun Microsystems and now widely promoted by nearly everyone other than Microsoft, offers an extremely diverse set of programming features, many of which are not available natively in PL/SQL. This chapter introduces the topic of creating and using Java stored procedures in Oracle, and shows how you can create and use JSP functionality from PL/SQL.

Oracle and Java

Starting with Oracle8i Database, the Oracle Database Server has included a Java virtual machine that allows Java programs to run efficiently in the server memory space. Many of the core Java class libraries are bundled with Oracle as well, resulting not only in a formidable weapon in the programmer’s arsenal, but also a formidable topic for a PL/SQL book! That’s why the objectives for this chapter are limited to the following:

• Providing the information you need to load Java classes into the Oracle database, manage those new database objects, and publish them for use inside PL/SQL

• Offering a basic tutorial on building Java classes that will provide enough guidance to let you construct simple classes to access underlying Java functionality

In preview, here is the usual way you will create and expose Java stored procedures:

1. Write the Java source code. You can use any convenient text editor or IDE, such as Oracle’s JDeveloper.

2. Compile your Java into classes and, optionally, bundle them into .jar files. Again, you can use an IDE or Sun’s command-line ...