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Abstract Syntax Notation One

A binary format for representing structured data.

Access Control List

The most common means by which a network security system decides to grant or deny access to network services. It is a list of the available services and the entities permitted to use each service.


In the SOAP encoding, accessors are the link between a compound type and its constituent parts. The SOAP encoding uses XML elements to hold the parts of compound types. The accessors are either the element names (for structs) or the position of the elements (for arrays).


The acronym for the four properties guaranteed by transactions: atomicity, consistency, isolation, and durability.


A utility used to remotely deploy and undeploy Web resources to an Axis server.


A predeployed service in Axis that can be used to remotely deploy and undeploy Web resources such as services, handlers, and chains.


IBM's Advertising and Discovery of Services, a simple, HTTP-based mechanism to advertise service descriptions on a Web page. For more information, see Compare with DISCO.

Application Service Providers

Companies that host applications for other companies to use on a subscription basis, removing the need to buy software and allowing them to outsource part of their IT departments.


In the SOAP encoding, arrays are subclasses of the SOAP-ENC:Array schema type.

authentication token

A small packet of data, usually encrypted, that is passed between a client and a server, and that contains information establishing an identity.

Axis engine

The main entry point to the SOAP processor.

Axis (Apache Extensible Interaction System)

The Apache SOAP v3 project; see


The Java object representing a fault (exception) generated during the processing of the SOAP message.


An encoding for binary data as described as a means of encoding email bodies in the IETF's MIME RFC. Base64 consists of only 64 of the 256 US-ASCII characters (A through Z, a through z, 0 through 9, +, /).

Bean-Managed Persistence

Data transfer between an entity bean's variables and the resource manager managed by the entity bean.


The mechanism in Axis used to serialize and deserialize XML elements into Java beans.


An operation within a service-oriented architecture. The bind operation describes the set of tasks associated with a service requestor preparing to invoke and invoking a Web service provided by a service provider.

binding mechanism

The mechanism by which the abstract definition of a Web service (a PortType) is mapped into a concrete representation of the Web service within a given messaging protocol, network protocol, and encoding scheme. The WSDL binding element is the binding mechanism used for Web services.


The body of a SOAP message is contained within the SOAP-ENV:Body element.


A characterization of interaction between businesses over the Internet. In a B2B interaction, applications between businesses communicate without human intervention being required during the interaction. Contrast with business-to-consumer (B2C)


A characterization of interaction between a human being and a business over the Internet. In a B2C interaction, a human being, often using a Web browser, invokes applications provided by a business. Contrast with business-to-business (B2B).


A method for generating a physical representation, the canonical form, of an XML document that accounts for the permissible changes. For example, the order of attributes, tab processing, and a standardized code set are used to check the logical equivalence of two documents.

capabilities-based lookup

A type of SOA find operation in which the target of the search is described in terms of what operations, characteristics, and so on the target Web services need to fulfill. Contrast with a name-based lookup, where the target of the service is described in terms of a well-known name or other identifier such as an object ID.

CDATA section

CDATA sections are used to escape blocks of text containing characters that would otherwise be recognized as markup. CDATA sections begin with the string <![CDATA[ and end with the string ]] >. They can occur in all places where character data is allowed.

certificate authority

A trusted third party whose purpose is to sign certificates for network entities that it has authenticated. Other network entities can check the signature to verify that a CA has authenticated the bearer of a certificate.

certificate path

The line of ancestral CAs that signed a given PKI certificate. If a trusted signer is identified in the certificate path, that verifies the binding between the certificate's subject and the public key. The certificate path is also called the certificate chain.

Certificate Revocation List

A list of certificates that have been revoked. This list is usually in a format specified by X.509.


A data record used for authenticating network entities such as a server or a client. A certificate contains standard information about its owner (called the subject) and the signing Certificate Authority (called the issuer), plus the owner's public key and the signature made by the CA. Network entities verify these signatures using CA certificates.


An ordered collection of Axis handlers. A chain is also an Axis handler.

character reference

An escape sequence for characters in XML documents. The syntax for character references is an ampersand, followed by a pound/hash sign (#), followed by either a decimal character code or lowercase x, followed by a hexadecimal character code, followed by a semicolon. Example: the 8-bit character code 128 will be encoded in a UTF-8 XML document as &#x80;.

client proxy

A component on the client that acts as a substitute (or proxy) for the Web service. A client proxy presents a programming language–specific interface to be used by a client application to invoke the Web service and presents the response from the Web service in a programming language–specific manner back to the client. The term client stub is also used as a synonym.


The Axis client-side configuration file.

compound type

In the SOAP encoding, compound types are composed of several parts, each of which has an accessor. These parts could be either simple or compound types.

concrete endpoint

An actual implementation of a Web service made available at a particular network address. A concrete endpoint is described using a WSDL port element.

connection-oriented messaging

Connection-oriented messaging requires that the sender and the recipient are both running and have a direct connection established between them. Also known as direct messaging.

Container Managed Persistence

Data transfer between an Entity Bean's variables and a resource manager managed by the Entity Bean's container.

control characters

Also known as non-whitespace control characters, these include the ASCII characters with codes 0 through 7, 9, 11, 12, or 14 through 31.

correlation ID

An identifier (usually a string) that is used to keep track of individual requests in a multistep series of Web services interactions.


The XML declaration is a processing instruction (PI) whose target is xml. It specifies the version of XML and, optionally, the character encoding in a document. Example: <?xml version="1.0" encoding="UTF-8"?>.


A file used as input into the Axis AdminClient to deploy new Web resources such as handlers and chains.


The process of generating a data structure from XML. Deserialization differs form parsing in that the data structure is typically focused on the logical structure of the document as opposed to its syntax.

direct messaging
See [connection-oriented messaging]

Microsoft's approach for using a simple, HTTP-based mechanism to advertise service descriptions on a Web page. For more information, see Compare with ADS.


An Axis handler that will locate and invoke the desired Web service.


A document-centric view of processing a SOAP message occurs when the body of the SOAP envelope is viewed as an XML document rather than as an RPC call.

Document Object Model

DOM provides an object-oriented view of XML documents by representing them as a hierarchy of objects mapped to XML markup (elements, attributes, text, comments, and so on).


A standards body jointly initiated by The United Nations body for Trade Facilitation and Electronic Business (UN/CEFACT) and OASIS to standardize XML business specifications. ebXML intends to develop a technical framework that will enable XML to be utilized in a consistent manner for the exchange of all electronic business data.


A markup language term denoting the pairing of start and end tags.

embedded value

In the SOAP encoding, a value that is not independent; that is, a value embedded at the top level of the serialization.

Enterprise Application Integration

A form of distributed computing where applications and business processes are combined to achieve higher goals. Although EAI can indicate integration both within and between organizations, we use EAI for intra-organizations in this book.

Enterprise Java Beans

A component architecture for the development and deployment of object-oriented, distributed, enterprise-level applications. Applications written using the Enterprise Java Beans architecture are scalable, transactional, and secure.


A named piece of information in an XML document. Internal entities are defined within the document. External entities have separate physical storage.

Entity Bean

An enterprise bean that represents persistent data maintained in a database. An Entity Bean can manage its own persistence or it can delegate this function to its container. An Entity Bean is identified by a primary key. If the container in which an Entity Bean is hosted crashes, the Entity Bean, its primary key, and any remote references survive the crash.

entity reference

Refers to the content of a named entity. The syntax for entity references is an ampersand (&), followed by the entity name, followed by a semicolon (;).


The SOAP envelope is the SOAP-ENV:Envelope element and its contents.

(File Transmission Protocol)

A standard Internet protocol to exchange files on top of TCP/IP. FTP is often used to download programs and large files.

global chain

An Axis chain that is invoked for all Web services.


The name that should be used when defining the Axis global chain that is invoked to process the request message.


The name that should be used when defining the Axis global chain that is invoked to process the response message.

grid computing

A model of computation where clusters of machines at various locations on the network are harnessed to perform various high performance computations.

guaranteed message delivery
See [reliable messaging]

The basic building block inside Axis. It links Axis to existing back-end systems. Handlers are grouped into chains.


An element of WSDL that describes how a SOAP fault message is communicated as a SOAP header.


All SOAP headers are contained inside the SOAP-ENV:Headers element.


The technique used to model in/out and multiple out parameters in Axis by wrapping the actual value in a class that can carry the modified value back to the requestor.

home interface

One of two interfaces for an enterprise bean. The home interface defines zero or more methods for managing an enterprise bean. The home interface of a Session Bean defines create and remove methods, whereas the home interface of an Entity Bean defines create, finder, and remove methods.

horizontal extensibility

Allows different parts of a SOAP message to be targeted toward different recipients along the message path. This is achieved through the use of SOAP intermediaries.

HTTP Basic Authentication (BASIC-AUTH)

An authentication mechanism in which a Web server authenticates an entity by extracting a user name and password from the HTTP request and comparing that data with existing user information stored in the web server.


A reliable messaging protocol using HTTP as a transport protocol, proposed by IBM; see


Hypertext Transfer Protocol layered over the SSL protocol.

hybrid parsing

Combines push, pull, and one-step parsing to best serve particular scenarios.

independent value

In the SOAP encoding, all values that appear at the top level of the serialization are considered independent.

Inquiry API

A set of public non-authenticated operations that allows users to extract information from the UDDI Business Registry.


A level in the W3C discovery stack. Inspection is a technique of discovering the service description given that the details about the service, a service identifier or URL for example, is already known. Examples of inspection include ADS and DISCO.


Also known as XML instance or document instance. Refers to an XML document as a specific instance from the set of possible documents allowed by a schema.

Interface Definition Language

A language to describe function or object interfaces in a distributed computing environment, allowing compilers to generate proxy and stub code to marshal parameters between different computers. In Web services, the IDL of choice is WSDL.

interface repository

A central store of metadata about CORBA components' interfaces. This is a CORBA-specific implementation of the SOA services registry role.


Processing nodes on the SOAP message path that are different from the requestor and the final recipient of the message.

Internet Engineering Task Force

The standards body that defines Internet operating protocols such as TCP/IP, URIs, and so on. The IETF's main documents are the RFCs.

J2EE Connector Architecture

An architecture for the integration of J2EE products with enterprise information systems. There are two parts to this architecture: a resource adapter provided by an enterprise information system vendor and the J2EE product that allows this resource adapter to be plugged in. This architecture defines a set of contracts that a resource adapter has to support to be plugged in to a J2EE product—transactions, security, and resource management.

Java 2 Platform Enterprise Edition

A meta-specification for developing and deploying enterprise applications with Java. J2EE platforms consist of a set of services, application programming interfaces (APIs), and protocols that provide the functionality for developing multitiered, Web-based applications.

Java Authentication and Authorization Services

A Java API that enables services to authenticate and enforce access controls on users. The reference implementation features a version of the standard Pluggable Authentication Module (PAM) framework and supports user-based authorization.

Java Community Processes

An open organization of international Java developers and licensees whose charter is to develop and revise Java technology specifications, reference implementations, and technology compatibility kits.

Java Cryptographic Architecture

A framework for providing cryptographic capabilities to Java programs.

Java Cryptography Extension

A Java framework and implementation of encryption, key generation, key agreement, and Message Authentication Code (MAC) algorithms. Support for encryption includes symmetric, asymmetric, block, and stream ciphers. The software also supports secure streams and sealed objects.

Java Management Extension

A universal, open technology for system management, ready to be deployed across all industries, wherever management is or will be needed. By design, this new standard is suitable for adapting legacy systems, implementing new management solutions, and plugging in to those of the future.

Java Message Service

An API for enterprise messaging systems. Implementations include IBM MQ Series and TIBCO Rendezvous.

Java Secure Socket Extension

A Java API that implements SSL and TLS protocols and supports data encryption, server authentication, message integrity, and client authentication.

Java Specification Requests

A proposed or final specification for an addition or modification to the Java platform. At any one time numerous JSRs are moving through the review and approval process.

(Java API For XML Processing)

Defines a vendor-independent API for parsing and transforming XML documents.

(Java Key Store)

A proprietary keystore format used by default in the Sun JDK's KeyStore API and keytool program.

(Java Web Service)

A Java file that Axis will automatically compile and deploy as a Web service.


A repository of keys and certificates.


A tool for managing keys and certificates.

Lightweight Directory Access Protocol

A protocol for accessing online directory services.

logical structure

The logical structure of an XML document describes the organization of the concepts that define the meaning of the document.


A secure hash, or message digest, algorithm developed by Ron Rivest.


A WSDL element that describes a collection of parts of an input, output, or fault data flow associated with an operation. A message can be abstract or concrete, and the use is made clear only when the message is examined in the context of a binding mechanism.

Message Authentication Code

A keyed-hash algorithm that is similar to secret-key digital signatures and is used to ensure data integrity. A hash value is calculated using a symmetric session key, which is included in the message itself, and then recalculated at the other end by the same key to verify that the data has not been altered in transit.


The object that is passed to each handler during the SOAP message flow through the Axis engine. The MessageContext object contains all the data needed to process the request or response SOAP message.

message-driven bean

An enterprise bean that receives and processes asynchronous messages. A message-driven bean has no state for a specific client, but its instance variables can maintain state relating to the handling of client messages, including an open database connection and an object reference to an EJB object. A client accesses a message-driven bean by sending messages to the destination for which the message- driven bean is a message listener.

message queuing

A messaging system built around the concept of message queues. Each message is addressed to a specific queue; clients extract messages from the queue(s) established to hold their messages.


A model for distributed computing where systems interact through the passing of messages containing data.


Can be used to define other languages. For example, XML Schema can be viewed as a language that describes the structure and datatypes of XML-based languages.


An Axis handler that will locate and invoke a Java method. The entire body of the SOAP message is passed as a DOM object to the method.


In SOAP encoding, a value that is referred to by more than one accessor is considered multireference.


A standard that lets you specify a unique label for the set of element names defined by a particular Document Type Definition (DTD). A document using that DTD can be included in any other document without having a conflict between element names. The elements defined in your DTD are then uniquely identified so that, for example, the parser can tell when an element called <name> should be interpreted according to your DTD, rather than using the definition for an element called name in a different DTD.

Network Address Translation

An address assignment system that allows an organization's IP network to appear from the outside to use a different IP address space than its component machines are actually using.

(Organization for the Advancement of Structured Information Standards)

See OASIS sponsors a DTD repository at

one-step parsing

Involves the parser generating a parse tree (typically, a DOM structure) from an XML document.


Documents containing sets of formal definitions of relations among terms in machine readable format, usually in the form of a taxonomy of terms and a set of inference rules to make sense of the terms.


A WSDL element that describes an individual method or function provided by a Web service. An operation is part of an abstract definition of a Web service interface (PortType).

peer-to-peer computing

A model of computation where nodes on the network are equal in status and can act as both clients to request information from other nodes and servers to provide that information to other nodes.

physical structure

The physical structure of an XML document describes the organization of syntax elements (elements, text, comments, and so on) in the document.

pivot point

The Axis handler in a targeted chain that is the point at which the Axis engine believes it has switched from processing the request SOAP message to processing the response SOAP message.


A WSDL element indicating the endpoint address of a Web service in a communications protocol-specific fashion (for example, URL for HTTP, email address for SMTP, and so on).


A WSDL element that describes a collection of message signatures (operation elements) that define the abstract interface of the Web service.


An identity assigned to a user as a result of authentication.

private key

The publicly unavailable key owned by an identity in a Public Key Cryptography system. It is used to decrypt incoming messages and sign outgoing ones.

Processing Instruction

A special directive to the applications processing XML documents. The syntax is <?PITarget ...?>. The PI target is a keyword meaningful to the processing application. Everything between the PI target and the ?> marker is considered the contents of the PI.


A section of XML documents that provides some metadata about the markup in the document such as information about the version of XML in use, information about the character encoding in use, information about the document's DTD, and any comments or processing instructions.

public key

The publicly available key in a Public Key Cryptography system, used to encrypt messages bound for its owner and to decrypt signatures made by its owner.

Public Key Infrastructure

The architecture, organization, techniques, practices, and procedures that collectively support the implementation and operation of a certificate-based public key cryptographic system.

Publication API

A set of authenticated UDDI operations that allows organizations to publish information to the UDDI Business Registry.


An operation within a service-oriented architecture, describing a contract between a service provider and a service registry. The publish operation describes the steps taken by a service provider to advertise a service description in a way that one or more service requestors can find that service description, and thereby be able understand what is required to invoke that service.

publish/subscribe messaging

A one-to-many model of messaging interaction where the sender sends a single message but copies it to multiple recipients. Also known as topic-based messaging.

pull parsing

Parsing mechanism in which the application always has to request the next piece of parsing information from the parser.

push parsing

Parsing mechanism in which the parser sends parsing events to the application processing an XML document.

Quality Of Service

A general term encompassing a set of metrics relevant to a particular distributed computing scenario. Typically these include aspects of security, transaction-management, response times.


A string, passed as part of an HTTP request during basic authentication, that defines a protected space. The protected resources on a server can be partitioned into a set of protected spaces, each with its own authentication scheme and/or authorization database.

reliable messaging

Process of delivering messages with various Quality of Service (QoS) options that guarantee the safe arrival of those messages at their destinations, even when machine failures occur. When reliable messaging is used, the following functionality is available: confirmation of receipt of messages, message logging and tracking, correlation of messages, retry attempts, and a choice of message delivery methods.

request message

The SOAP message that will be processed by the SOAP engine.

Resource Description Framework

An XML application that allows the description of resources as structured metadata in machine readable format, and the exchange and reuse of these resources in various and possibly unrelated applications.

response message

The response from a SOAP engine. Typically, this is generated as a result of processing a request message.

Remote Method Invocation over Internet Inter-ORB Protocol

An implementation of RMI using the CORBA IIOP protocol. RMI over IIOP provides interoperability with CORBA objects implemented in any language if all the remote interfaces are originally defined as RMI interfaces.

role-based access control

An access control mechanism based on roles: abstract logical groupings of users that are defined by a system administrator. When an application is deployed, roles are mapped to security identities, such as principals or groups, in the operational environment.

root element

The first element in an XML document. The name derives from the fact that this element is the root of the element hierarchy.

Round-Robin Domain Name Service

A DNS method of managing server congestion by distributing connection loads across multiple servers (containing identical content).

(Remote Procedure Call)

The concept of executing a function on another process or machine.


An Axis handler that will locate and invoke a Java method as a Web service. The body of the SOAP message is assumed to be an RPC call containing the method name and serialized versions of the parameters.


The most widely known public key cryptographic algorithms. The security of RSA relies on the relative ease of finding large prime numbers and the comparative difficulty of factoring large integers.

(Simple API For XML)

Defines a simple event-based API for XML push parsing.

schema compilers

Tools that analyze XML schemas and code-generate serialization and deserialization modules specific to the schemas.

Secure Socket Layer

A security protocol that ensures confidentiality and integrity of data exchanged over the Internet. The protocol allows client and server applications to communicate in such a way that third parties cannot eavesdrop or tamper with the content of the communication. Servers are always authenticated and clients are optionally authenticated.

Security Assertion Markup Language

A proposed standard that specifies a way of exchanging authentication and authorization information as an XML document.

semantic Web

The evolution of the current Web, where Web information is augmented with machine-readable data about the semantics of the content, allowing automatic integration and interoperability between machines.


The process of emitting XML markup from a data structure.


The Axis server-side configuration file.


An Axis Java class that is the portal through which clients will connect to the remote Web Service.


An Axis Java class that is used by the client to give the Axis engine metadata about the Web service being invoked.

service description

A unit of meta data describing the capabilities of a Web service. A service description is key to a service- oriented architecture in that it describes everything a service requestor needs to know in order to invoke a Web service. The most popular form of service description is WSDL. The W3C describes a service description stack, outlining all of the technologies associated with describing many facets of a Web service.

service implementation definition

A subset of WSDL elements focused on the actual endpoint definition of a Web service. This forms a conventional division of a WSDL document, separating the service implementation definition from service interface defintion.

service interface definition

A subset of WSDL elements focused on the reusable portions of a Web service; that is, elements that are likely to be shared between many actual Web service implementations hosted by different service providers. This forms a conventional division of a WSDL document, separating the service implementation definition from service interface defintion.

service orchestration

The act of combining two or more Web services to produce a higher level or more sophisticated Web service. Popular service orchestration techniques include IBM's WSFL and Microsoft's XLANG.

service oriented architecture

An abstract pattern that applies to a wide variety of Web services situations. SOA defines an architecture consisting of three roles (service provider, service registry, and service requestor) that can be fulfilled or implemented by a variety of techniques. SOA also defines the contracts between these roles in terms of three operations: publish, find, and bind.

service provider

A role within a service-oriented architecture. A service provider is any business or entity that hosts one or more Web services for access by service requestors. Service providers publish service descriptions to one or more service registries and receive service invocations from one or more service requestors. Think of a service provider as a "server" in a client-server relationship with a service requestor.

service registry

A role within a service-oriented architecture. A service registry is any mechanism by which one or more service descriptions can be published by service providers and searched for or found by service requestors.

service requestor

A role within a service-oriented architecture. A service requestor is any business or entity that invokes a Web service provided by a service provider. Service requestors do find operations against one or more service registries to retrieve a service description for a Web service. Based on that service description, the service requestor invokes a Web service to fulfill some task within a business process. Think of a service requestor as a "client" in a client-server relationship with a service provider.

Session Bean

An enterprise bean that is created by a client and usually exists for the duration of a single client-server session. A Session Bean performs operations, such as calculations or accessing a database, for the client. Although a Session Bean might be transactional, it is not recoverable should a system crash occur. Session Bean objects can be either stateless or they can maintain conversational state across methods and transactions. If a Session Bean maintains state, the EJB container manages this state in any case where the object must be removed from memory. However, the Session Bean object itself must manage its own persistent data.

SGML/XML application

A term historically rooted in document-centric uses of SGML and XML. It describes the set of SGML/XML documents allowed by a schema.

(Secure Hash Algorithm 1)

A message digest function designed by NIST and the NSA.

Simple Network Management Protocol

A network protocol used on the Internet to control devices. It is also used to monitor devices over a network.

Simple Object Access Protocol

A lightweight protocol for exchange of information in a decentralized, distributed environment. It is an XML-based protocol that consists of three parts: an envelope that defines a framework for describing what is in a message and how to process it, a set of encoding rules for expressing instances of application-defined datatypes, and a convention for representing remote procedure calls and responses. SOAP can potentially be used in combination with a variety of other protocols; however, the only bindings defined in this document describe how to use SOAP in combination with HTTP and HTTP Extension Framework (definition from

simple type

In the SOAP encoding, simple types map to the built-in XML Schema types, and types derived from them using schema extensibility.


In the SOAP encoding, a value that is referred to by only one accessor is considered single-reference.

single sign-on

An authentication system set up such that the user has to sign-on only once to access multiple systems and applications. Possible benefits include easier access for the user and greater security (the user does not have to remember as many passwords).


A server-side component that intermediates between the Web services middleware (such as the Axis engine) and the target Web service implementation. A skeleton will decode information sent from the service requestor and invoke the target Web service using a programming-language specific API. The skeleton also translates the response from the target Web service back into a format expected by the Web services middleware. The term server stub is also used as a synonym.

(Simple Message Transport Protocol)

A protocol for email.

SOAP Digital Signature

A specification describing the form and content of a SOAP 1.1 header entry carrying digital signature information.

SOAP Intermediary

A SOAP node that receives and forwards SOAP messages along the message path, acting on the messages.

software agent

For the purposes of this book, a program that assists people and acts on their behalf. Agents function by allowing people to delegate work to them.


In the SOAP encoding, compound types whose parts are distinguished only by their name.


Identify pieces of information in markup languages. They denote the beginning and end of elements. Elements begin with a start tag, such as <name>, and end with an end tag, such as </name>.


An Axis chain that has a pivot point handler.


A proxy tool that comes with Apache Axis. It allows for the monitoring of SOAP messages over HTTP.

TCP router

A networked service that acts as a load balancing front-end to the clustered Web server. TCP request packets arrive at the public interface to the cluster where they are routed to an available processing node over the internal network connecting the router to the server nodes.


An Internet protocol that allows you to log on to another computer on the Internet and interact with it as if you were physically present at that remote computer.


Refers to a technology model, a reusable abstract definition that is typically published by a standards body or an industry organization and referenced in the specification of a Web service that conforms to it.

topic-based messaging
See [publish]

An atomic unit of work that modifies data. A transaction encloses one or more program statements, all of which either complete or roll back. Transactions enable multiple users to access the same data concurrently.

Transaction Internet Protocol

A simple two-phase commit protocol that specifies how different nodes agree on the outcome of a transaction; the content on which the nodes agree moves through other protocols like HTTP. TIP is currently a proposed IETF standard.

Transaction Manager

An object that provides the services and management functions required to support transaction demarcation, transactional resource management, synchronization, and transaction context propagation.

transmission primitive

A characterization of the message flow associated with an operation. There are four types of transmission primitives: request-response, one-way, solicit-response, and notification.


The means through which a SOAP message is delivered to and from the SOAP processor; for example, HTTP.

Transport Layer Security protocol

The latest version of the SSL protocol. It is an enhancement of SSL version 3.0, and is a proposed Internet Standard (see RFC2246).

transport listener

The piece of code that will wait for a SOAP request message, locate (or create) an Axis engine, and then invoke the engine with the request message.

transport sender

The piece of code that will take the response message generated by the Axis engine and send it to the appropriate target SOAP processor.

transport-specific chain

An Axis chain that is invoked based on the transport mechanism used.

Two-Phase Commit

The process by which a relational database ensures that distributed transactions are performed in an orderly manner. In this system, transactions can be terminated by either committing them or rolling them back.


A collection of Java interfaces and implementations for client access to a UDDI registry (

UDDI Business Registry

An instance of the UDDI registry hosted at

UDDI Operators

Companies that run public instances of a UDDI Business Registry. Operators have signed an operator agreement that commits them, among other things, to support the UDDI API and to replicate registrations among themselves on a periodic basis.


A file used as input into the Axis AdminClient for undeploying Web resources such as handlers and chains.

Uniform Resource Identifier

The Web naming and addressing technology, consisting of strings that identify resources on the Web, such as documents, images and email addresses.

Universal Description, Discovery and Integration

A standards-based approach to very sophisticated service registry implementation. UDDI is also an implementation of a services registry located at

(Uniform Resource Locator)

A subset of URIs referring to Internet addresses (for example, URLs consist of an access protocol specifier (http), a host IP specifier (, and optionally the path to a file or resource residing on that host (/doc).

(Uniform Resource Name)

URIs that are globally unique and persistent. They begin with the specifier urn:.

(Universally Unique Identifier)

128-bit globally unique identifiers. They combine network card (Ethernet) addresses with a high-precision timestamp and an increment counter. For example: 2FAC1234-31F8-11B4-A222-08002B34C003.


A valid XML document is well-formed and follows the constraints of some schema.

vertical extensibility

Allows new pieces of information to be introduced in SOAP messages without breaking existing applications. This is achieved through the use of SOAP headers.

(World Wide Web Consortium)

The international body that governs Internet standards. It was created in 1994 and is open to all interested organizations. Participation in the W3C allows member organizations to jointly develop protocols that promote the evolution of the Web while insuring its interoperability. The W3C holds the specifications for many of the Web technologies such as HTML, XML, and RDF.

W3C Note

A dated, public recognition of an idea, comment, or document by the W3C. Members wishing to have their ideas published at the W3C site as a Note must follow the Submission process.

W3C Working Draft

A W3C-published document that represents work in progress and a commitment by W3C to pursue work in the area focused on. A Working Draft does not imply consensus by a group or the W3C.

(Web Distributed Data Exchange)

A language- and platform-neutral XML technology for exchanging data between applications.

Web service

A platform- and implementation-independent software component that can be described using a service description language; published to a registry of services; discovered through a standard mechanism (at runtime or design time); invoked through a declared API, usually over a network; and composed with other services.

Web Services Deployment Descriptor

An XML-based file used that will be used (in future Axis releases) for deploying Web resources.

Web Services Description Language

A component of a service description that describes the interface definition of the Web service, details related to binding (network protocol and data encoding requirements), and the network location of the Web service. WSDL is published at

Web Services Endpoint Language

A component of a service description that describes aspects of the Web service not directly addressed by the WSDL. These aspects are typically non-functional, not directly impacting the way the Web service invocation message must be formatted by the service requestor. Examples of non-functional properties include, privacy policy, quality of service (QoS) assertions, and so on. WSEL currently exists only as a high-level requirement as part of WSFL.

Web Services Flow Language

A mechanism for service orchestration based on flow composition. WSFL was published by IBM at


A well-formed XML document follows the rules of XML syntax.

X.500 distinguished name

A name by which an entity entered in an X.500 directory service is unambiguously identified.

XML digital signature

Addendum to an XML document containing information so that the authenticity of the signed document and also the identity of the signer can be verified.

XML encryption

A method for encrypting data and a specification for representing the resulting ciphertext in XML.

XML Key Management Services

A specification to access PKI in XML. XKMS uses the relative simplicity of XML to implement two key aspects of secure e-commerce, according to the specification's authors, Microsoft Corp. and VeriSign Inc. In the near future, the specification will be submitted to Web standards bodies for consideration as an open Internet standard. XKMS aims to simplify application building by moving digital signature handling and encryption out of the applications themselves.

XML protocol

Encompasses a set of rules and conventions for distributed computing using XML. XML protocols govern how communication happens and how data is represented in XML format on the wire. Examples of XML Protocols are WDDX, XML-RPC, and SOAP.

XML Transaction Authority Markup Language

A set of XML-based message formats and interaction models that Web services can use to enable business transactions between multiple parties on the Internet. XAML is a vendor-neutral standard developed jointly by Bowstreet, Hewlett-Packard, IBM, Oracle, and Sun.


A simple RPC mechanism that uses XML messages.

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