Introduction
Please feel free to send any questions or comments to Ted Stockwell
ServiceTango is an application server for building,
deploying, and managing network-delivered business applications.
ServiceTango is designed to be
OSGi (Open Services Gateway Initiative) 1.0 compatible.
ServiceTango's primary goal is to use the Java (TM) programming language's platform independence and dynamic code-loading capability to make development and dynamic deployment of business applications easier.
This goal is met in two ways. First, the OSGi Framework Specification provides
a consistent programming model during application development; it supports the
development and use of services by decoupling a service's specification
(the interface) from its implementation.
Thereby:
Developers can provide multiple implementations to the same service interfaceThis support is critical, because ServiceTango is designed to run on a variety of hardware; different hardware characteristics could affect many aspects of the service implementation, yet a stable service interface ensures the stability of the overall software system.
Developers who use a service can code against that service's interface without regard to its implementation
For example, in one deployment a logging service might store log messages on a hard drive, while in another deployment the log entries may be saved remotely. The developers of the two logging service implementations implement the same interface; the developers of services that use a logging service write code against the logging service interface, without regard to which implementation their service might use.
Second, it provides life-cycle management functionality that permits application developers to partition applications into small self-installable components. These components are called bundles. Bundles can be downloaded on demand and removed when they are no longer needed. When a bundle is installed and activated in ServiceTango it can register any number of services that can be used by other bundles.
This dynamic aspect makes the software extensible on the device after deployment: new bundles can be installed for added features or existing bundles can be updated for bugfixes without bringing down the entire system.
Capabilities
Standard OSG platform, including web server and log handling
Restrictions
The OSG device manager interface is not supported.
Requirements
Developing with ServiceTango requires that you have the following:
Runtime environment that supports Java 2. For instance, Java Development Kit (JDK) v1.2 or better.
Development environment including a Java compiler and interpreter. For instance, JBuilder Foundation (free!).
An understanding of Java programming.
ServiceTango is distributed as a .zip file.
It's easy to expand the ServiceTango download with Java's jar tool.
Set your current directory to the directory in which you would like to create the ServiceTango home directory. On a Windows workstation this would typically be the root directory.
Then type the command:jar xvf <file-name>
where <file-name> is the substituted with the name of the ServiceTango distribution file that you downloaded. This command creates a directory named ServiceTango off the current directory and copies the ServiceTango files into the new directory. This directory is referred to as the <ServiceTango-Home> directory.
Execution
To start ServiceTango simple execute the command:
java -cp <ServiceTango-Home>/lib/servicetango.jar org.servicetango.startup.ServiceTango [options]
where [options] may include the following:
-config
<file-name>
where <file-name> is the name of a file that contains configuration properties. This is the server's XML configuration file. If not specified then the server will try to use a file named "servicetango.xml
" in the current directory.See the Configuration section for details.
See the Services section for instructions on using the services that come with ServiceTango.
See the Examples section for instructions on starting the ServiceTango instance included in the distribution.
Components
Tomcat
Tomcat's license is reproduced below as required...
Java API for XML Parsing 1.0.1
ServiceTango is built with the following third-party libraries and components (other than what's contained in the Java 2 platform):
Tomcat is the Reference Implementation for the Java Servlet 2.2 and JavaServer Pages 1.1 Technologies.
Tomcat is the official reference implementation for these complementary technologies.
Tomcat also contains an HTTP 1.0 compliant web server.
Copyright (c) 1999 The Apache Software Foundation. All rights
reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
3. The end-user documentation included with the redistribution, if
any, must include the following acknowlegement:
"This product includes software developed by the
Apache Software Foundation (http://www.apache.org/)."
Alternately, this acknowlegement may appear in the software itself,
if and wherever such third-party acknowlegements normally appear.
4. The names "The Jakarta Project", "Tomcat", and "Apache Software
Foundation" must not be used to endorse or promote products derived
from this software without prior written permission. For written
permission, please contact apache@apache.org.
5. Products derived from this software may not be called "Apache"
nor may "Apache" appear in their names without prior written
permission of the Apache Group.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
The JAVA API for XML Parsing (JAXP) Optional Package provides basic functionality for reading, manipulating, and generating XML documents through pure Java APIs.
Future Enhancements
The ServiceTango Management Panel
The ServiceTango Management Panel is an application which is used to get information about the entities running in a ServiceTango instance, and to perform operations on those entities (such as stopping or installing bundles)Support for the Java Network Laucher Protocol and API.
Bundles that export JNLP services will provide a higher level API to developers for developing network deployable and automatically updating applications than that provided by the OSGi Framework.A mail service.
A bundle that exports mail services for sending and receiving mail messages. Because this service will be available to other applications via the OSGi API any other application installed into the same ServiceTango instance will instantly know the correct way to get and send e-mail.An e-mail client application.
A complete, Swing-based, e-mail application that can be automatically updated.