Eclipse Metro

Metro is a high-performance, extensible, easy-to-use web service stack. Although historically an open-source part of the GlassFish application server, it can also be used in a stand-alone configuration.^[1] Components of Metro include: JAXB RI, JAX-WS RI, SAAJ RI, StAX (SJSXP implementation) and WSIT. Originally available under the CDDL and GPLv2 with classpath exception,^[2] it is now available under Eclipse Distribution License [Wikidata]

Metro

Original author(s)	Sun Microsystems
Developer(s)	Eclipse Foundation
Initial release	September 17, 2007; 17 years ago (2007-09-17)
Stable release	3.0.1 / April 14, 2021; 4 years ago (2021-04-14)
Written in	Java
Platform	Jakarta EE
Type	web service framework
License	EDL 1.0 [Wikidata]
Website	projects.eclipse.org/projects/ee4j.metro

History

Originally, the Glassfish project developed two semi-independent projects:

• JAX-WS RI, the Reference implementation of the JAX-WS specification
• WSIT, a Java implementation of some of the WS-* and an enhanced support for interoperability with the .NET Framework. It is based on JAX-WS RI as "Web Service layer".

In June 2007, it was decided to bundle these two components as a single component named Metro.^[3]

Features

Metro compares well with other web service frameworks in terms of functionality. Codehaus started a comparison^[4] which compared Apache Axis 1.x, Axis 2.x, Celtix, Glue, JBossWS, Xfire 1.2 and JAX-WS RI + WSIT (the bundle was not yet named Metro at that time). This was later updated by the ASF to replace Celtix with CXF and to include OracleAS 10g.^[5]

Metro includes JAXB RI, JAX-WS RI, SAAJ RI, SJSXP, and WSIT, along with libraries that those components depend on, such as xmlstreambuffer, mimepull, etc.^[6]

Its features include:

• Basic Profile 1.1 Compliant
• Easily Create Services from POJOs
• RPC-Encoding
• Spring Support
• REST Support
• Soap 1.1/1.2
• Streaming XML (StAX based)
• WSDL 1.1 ->Code (Client)/(Server)
• Server and Client-side Asynchrony^[5]

Supported WS-* Standards^[5]

WS-Addressing	WS-Atomic Transaction	WS-Coordination
WS-Metadata Exchange	WS-ReliableMessaging	WS-Policy
WS-Secure Conversation	WS-Security Policy	WS-Security
WS-Trust	WSDL 1.1 Support

Supported Transport protocols include:

• HTTP
• JMS
• SMTP/POP3
• TCP
• In-VM

Metro augments the JAX-WS environment with advanced features such as trusted, end-to-end security; optimized transport (MTOM, Fast Infoset), reliable messaging, and transactional behavior for SOAP web services.

Market share

Metro is bundled with Java SE 6 in order to allow consumers of Java SE 6 to consume Web Services.^[7]

Metro is bundled with numerous application servers such as:^[8]

• GlassFish
• Sun Java System Application Server Platform Edition 9.x
• Oracle WebLogic Server
• JBoss (version 5.x only)
• TmaxSoft JEUS 6.x

The JAXB reference implementation developed for Metro is used in virtually every Java Web Services framework (Apache Axis2, Codehaus XFire, Apache CXF) and Application Servers.