If you install Oracle Database with Oracle JVM option, then the database is Java-enabled. That is, it is ready to run Java stored procedures and Java Database Connectivity (JDBC).
This section contains the following topics:
4.1.1 Configuring the Oracle JVM Option within the Oracle Database Template
Configure Oracle JVM option within the database template. This is the recommended method for Java installation.
The Database Configuration Assistant enables you to create database templates for defining what each database instance installation will contain. Choose Oracle JVM option to have the Java platform installed within your database.
4.1.2 Modifying an Existing Oracle Database to Include Oracle JVM
If you have already installed Oracle Database without Oracle JVM, then you can add Java to your database through the modify mode of the Database Configuration Assistant of Oracle Database 12c Release 1 (12.1). The modify mode enables you to choose the features, such as Oracle JVM, that you would like to install on top of an existing Oracle Database instance.