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)
Java Database Connectivity for CDC/FP (JDBC, JSR 169)
XML API (JSR 280)
Security Optional Package
Web Services (JSR 172)

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:

Full RMI call semantics
Marshalled object support
RMI wire protocol
Export of remote objects
Client- and server-side distributed garbage collection
The Activator interface and the client-side activation protocol
Registry interfaces and export of a Registry remote object

For a complete description, including differences from Java SE RMI, see http://jcp.org/en/jsr/detail?id=66

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 http://download.oracle.com/javame/config/cdc/opt-pkgs/api/jsr169/index.html.

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.

XML API (JSR 280)

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

Java API for XML Processing (JAXP)
Simple API for XML Processing (SAX)
Streaming API for XML (StAX, JSR 173)
Document Object Model (DOM) Core
DOM Events and View

The API definition is at http://download.oracle.com/javame/config/cldc/opt-pkgs/api/xml/jsr280/index.html.

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.