JCA 2.0

1
JCA 2.0

• Eric. Boucher APS
• boucher_at_aps.anl.gov
• EPICS Collaboration Meeting - June 18-20, 2003

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Introduction

• What is JCA
• Why a new version
• New features
• Compatibility
• Future of JCA

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What is JCA
JCA is a java implementation of the Channel
Access library It allows standalone Java
application to connect to CA servers. It is
also possible, with some restrictions to develop
web-based applications. It is not a pure Java
implementation.
4
Why a new version

• Previous version was released in 1999
• More and more users
• Release of CA 3.14
• Cleaner API
• Add new features

5
Overview

• New design
• Backward compatible with JCA 1.0
• Support for both EPICS 3.13 and 3.14
• Requirement
• Java 1.2 or higher
• Epics 3.13 or higher
• Successfully build for the following platforms
• Win32
• Linux-x86
• Solaris-sparc

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New Features

• Separation between interfaces and implementation
• Introduction of the concept of Context
• All exception handlers now implemented
• Many helper functions added
• Different level of programation

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Design
Channel
Context
Channel
Channel
Channel
Context
Java application
Channel
Channel
Channel
Channel
Context
Channel
Channel
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Thread Control
CA
9
Browser Integration
CA server
JCA 2.0
Java Plugin
WEB server
Load applet code
Browser
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JCA 1.0
JCA2.0
Bridge
JCA1.0 Application

• Backward compatible
• Possible loss of performance

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EPICS 3.13

• Preemptive callback disabled
• Only one context allowed

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Future of JCA

• Support from different labs.
• SNS ORNL COSYLab DESY
• Web page
• Mailing list
• Pure java version
• JCA components