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Oracle® Java Micro Edition Embedded Client Architecture Guide
Release 1.1
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3 Optional Packages

This chapter describes optional packages that provide useful functions for some, but not all, deployments. Optional packages support remote method invocation, database connectivity, XML processing, encryption, and web services. The Customization Guide describes how to remove and install these optional packages to optimize the use of device memory.

This chapter includes the following topics:

J2ME Remote Method Invocation (RMI, JSR 66)

The RMI interface enables distributed applications to invoke each other's methods across a network. The Oracle Java Micro Edition Embedded Client RMI API is a subset of the Java SE RMI API, and includes the following capabilities:

For a complete description, including differences from Java SE RMI, see

Java Database Connectivity for CDC/FP (JDBC, JSR 169)

JDBC is a Java interface for querying and updating a relational database with SQL statements. JDBC for CDC/FP (which is supplied with Oracle Java Micro Edition Embedded Client) is a subset defined at

To use JDBC, you must logically connect the interface to an actual database as described in the Oracle Java Micro Edition Embedded Client Customization Guide.


The XML API supports the XML data format in mobile and embedded devices. It consists of subsets of the following:

The API definition is at

Security Optional Package

The security optional package included with Oracle Java Micro Edition Embedded Client consists of javax.crypto classes that perform encryption, key generation, key agreement, and Message Authentication Code (MAC) generation. Support for encryption includes symmetric, asymmetric, block, and stream ciphers. This package also supports secure streams and sealed objects.

Web Services (JSR 172)

The Web Services optional package enables applications to communicate with XML-based enterprise web services and to parse XML data.

In Oracle Java Micro Edition Embedded Client, the Web Services package and the XML API package are mutually exclusive. The XML API optional package is installed by default. The Customization Guide describes how to swap the packages.