Given that
metadata is a set of descriptive, structural and administrative
data
In the pursuit of knowledge, data (; ) is a collection of discrete Value_(semiotics), values that convey information, describing quantity, qualitative property, quality, fact, statistics, other basic units of meaning, or simply sequences of sy ...
about a group of
computer data (for example such as a
database schema), Java Metadata Interface (or JMI) is a platform-neutral specification that defines the creation, storage, access, lookup and exchange of metadata in the
Java programming language
Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers ''write once, run anywh ...
.
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History
The JMI specification was developed under the
Java Community Process
The Java Community Process (JCP), established in 1998, is a formalized mechanism that allows interested parties to develop standard technical specifications for Java technology. Anyone can become a JCP Member by filling a form available at thJCP w ...
and is defined by
JSR 40 (a JSR is the formal document that describe proposed specifications and technologies for adding to the
Java platform
Java is a set of computer software and specifications developed by James Gosling at Sun Microsystems, which was later acquired by the Oracle Corporation, that provides a system for developing application software and deploying it in a cro ...
).
JMI is based on the
Meta-Object Facility
The Meta-Object Facility (MOF) is an Object Management Group (OMG) standard for model-driven engineering. Its purpose is to provide a type system for entities in the CORBA architecture and a set of interfaces through which those types can be creat ...
(or MOF) specification from the
Object Management Group
The Object Management Group (OMG) is a computer industry standards consortium. OMG Task Forces develop enterprise integration standards for a range of technologies.
Business activities
The goal of the OMG was a common portable and interoperab ...
(or OMG). The MOF is a
metamodel
A metamodel or surrogate model is a model of a model, and metamodeling is the process of generating such metamodels. Thus metamodeling or meta-modeling is the analysis, construction and development of the frames, rules, constraints, models and ...
(a
model
A model is an informative representation of an object, person or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin ''modulus'', a measure.
Models c ...
of any kind of metadata) used notably to define the
Unified Modeling Language
The Unified Modeling Language (UML) is a general-purpose, developmental modeling language in the field of software engineering that is intended to provide a standard way to visualize the design of a system.
The creation of UML was originally m ...
(or UML).
It supports the exchange of metadata through
XMI. XMI is a standard for exchanging metadata information via
Extensible Markup Language
Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. T ...
(or XML). The MOF/XMI specifications are used for the exchange of UML models.
Usage
Essentially, JMI can be used to write tools in Java for manipulating UML models, which can be used in
Model Driven Architecture
Model Driven Architecture (MDA) is a software design approach for the development of software systems. It provides a set of guidelines for the structuring of specifications, which are expressed as models. Model Driven Architecture is a kind of doma ...
and/or
Model Driven Development
Model-driven engineering (MDE) is a software development methodology that focuses on creating and exploiting domain models, which are conceptual models of all the topics related to a specific problem. Hence, it highlights and aims at Representati ...
. There are many implementations of JMI, including the Reference Implementation from
Unisys
Unisys Corporation is an American multinational information technology (IT) services and consulting company headquartered in Blue Bell, Pennsylvania. It provides digital workplace solutions, cloud, applications, and infrastructure solutions, ...
,
SAP NetWeaver
SAP NetWeaver is a software stack for many of SAP SE's applications. The SAP NetWeaver Application Server, sometimes referred to as WebAS, is the runtime environment for the SAP applications and all of the mySAP Business Suite runs on SAP WebAS: ...
and
Sun Microsystems's open-source implementation from the
NetBeans
NetBeans is an integrated development environment (IDE) for Java. NetBeans allows applications to be developed from a set of modular software components called ''modules''. NetBeans runs on Windows, macOS, Linux and Solaris. In addition to Java ...
group. JMI is compatible with
Java SE
Java Platform, Standard Edition (Java SE) is a computing platform for development and deployment of portable code for desktop and server environments. Java SE was formerly known as Java 2 Platform, Standard Edition (J2SE).
The platform uses Ja ...
1.3 and above through:
* Standardized mappings from the MOF modeling constructs to Java;
* Reflective APIs for generic discovery and navigation of metadata models and instances.
See also
External links
JSR 40
Metadata Interface
Metadata
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