Home > Articles

  • Print
  • + Share This

Web Services for J2EE

At the time of writing, Web Services are not an integral part of J2EE. However, the overall intention and roadmap has been laid out. This section examines how Web Services fit with the J2EE model and how they can be used with J2EE components.

J2EE Web Service Architecture

J2EE will be both a provider and consumer of Web Services. Figure 20.2 shows the overall architecture, with business logic being provided by EJBs (although other classes could be used). The functionality offered by the business components will be described by a WSDL document (or similar), and this can then be used to build clients that use this functionality.

SOAP RPC calls will be handled by a router component based around a servlet. This will dispatch calls to the associated EJB or other component. The router that handles document-centric SOAP messages will also be servlet-based. In either case, the precise nature of the servlet will depend on the type of underlying transport over which the messages are sent.

The J2EE business components may themselves use other Web Services to help them deliver business functionality. In this case, the components will take advantage of the client-side Web Service APIs to call out to these Web Services.

Figure 20.2 Overall J2EE Web Service architecture.

The Web Service runtime will consist of a variety of filters, providers, and helpers that will be used in combination with the routing servlets and basic, low-level APIs. These helpers will deliver additional value on top of the basic APIs, such as ebXML quality of service guarantees.

Tools and Technologies

There are a number of JSRs that are in progress in the Java Community Process (JCP) to define Web Service APIs for Java. These include the following:

  • JSR101, Java APIs for XML-based RPC (JAX-RPC), provides APIs for invoking RPC-based Web Services over SOAP. It defines how interactions should take place and provides the basis for automated tools to produce stubs and skeletons. It also specifies type mapping and marshalling requirements between Java and SOAP/WSDL.

  • JSR067, Java APIs for XML Messaging (JAXM), defines APIs for creating document-centric SOAP messages that can be exchanged either synchronously or asynchronously. Vendors can provide messaging profiles on top of this that offer value-added services, such as ebXML.

  • JSR093, the Java API for XML Registries (JAXR), defines a two-tier API for accessing registry information stored in XML format. This is targeted at Web Service-related registries, such as UDDI registries and ebXML registry/repositories, as well as other generic XML registries.

The contents and status of these JSRs are available through the JCP Web site at http://www.jcp.org/.

The role that each of these APIs plays in the J2EE Web Service architecture is shown in Figure 20.3. All of these APIs are intended for inclusion in J2EE 1.4 (as defined in JSR151). In the interim, they will be delivered as part of the JAX Pack, along with other Java APIs for the manipulation of XML. The first JAX Pack was delivered in Fall 2001.

Figure 20.3 J2EE Web Service APIs.

Until the finalization and release of J2EE 1.4, there are various sources of Java-based Web Service functionality:

  • The Apache Software Foundation provides the Axis toolkit for the creation and use of SOAP-based Web Services that can be deployed in most servlet containers. Axis is tracking the JAX-RPC JSR as well as the progress of SOAP 1.2. The predecessor to Axis was Apache's SOAP toolkit 2.2. The Axis toolkit can be found at http://xml.apache.org/axis.

  • IBM provide their Web Services Toolkit (WSTK) through their Alphaworks developer site. The WSTK provides a set of tools and APIs on which to build Web Services. The WSTK integrates with the Apache Tomcat servlet engine and IBM's WebSphere application server. IBM's Web Service Toolkit can be found at http://alphaworks.ibm.com/tech/webservicestoolkit.

  • As the various JSRs reach maturity, they will be obliged to release a reference implementation (RI) of their functionality. These various RIs are available for individual download from Sun and are also bundled as part of the JAX Pack, also available from Sun. You can download the latest versions of these implementations from http://java.sun.com/webservices.

  • Some Web Service functionality is available in shipping J2EE application servers. An example of this is the BEA WebLogic server 6.1 that provided Web Service functionality that pre-dates the final outcomes of any of the related JSRs. Due to the nature of the JCP, most vendors are able to track the progress of the JSRs and deliver functionality early to their customers.

If you want to investigate or use Web Service functionality in your applications, the appropriate choice will depend on the style and robustness you require.


At the time of writing, the Web Service standards and their Java APIs were still works in progress. Hence, the primary vehicle used in subsequent sections for creating and using RPC-style Web Services is Apache's Axis toolkit. This shows many indications that it is tracking the JAX-RPC JSR and so should have similar features and tools to the eventual reference implementation.

Integrating Web Services with Existing J2EE Components

Most development projects involve using or adapting existing functionality. Projects based on Web Services will be no different. In fact, a project can be specifically focused at exposing existing functionality to clients in the form of Web Services. So, how do you expose existing J2EE functionality as Web Services?

For a traditional J2EE application, business logic is contained in EJBs. This functionality is usually made available to client applications through servlets and JSPs. If the clients are Web browsers, these Web components will generate and consume HTML. Similarly, if the clients are mobile applications, the Web components may generate and consume Wireless Markup Language (WML). However, these WML Web components share the same business logic—they just provide a different front-end or channel for it. Web Service clients are no different in that respect from HTML or WML clients. The SOAP router servlet, together with helper classes, acts as a server-side wrapper for the business logic, delivering it to Web Service clients. This situation is shown in Figure 20.4.

Figure 20.4 Web Services are just another channel through which to access business functionality.

The other type of J2EE component in which application logic can be held is a servlet or JSP. You may ask how you would wrap this functionality for use as a Web Service. Well, the issue here is that many of the Web components in question are already acting as channels to some form of client (as shown in Figure 20.4). Consequently, wrapping them makes no sense. What you should do is create a replacement for such a Web component that is targeted at Web Service clients rather than Web browsers. If your Web components are well designed, you should be able to reuse the JavaBeans, servlet filters, and helper classes (even servlets/JSPs that they use) as part of your Web Service implementation. If you already have servlets or JSPs that generate XML, you might be able to migrate them to meet your Web Service needs or transform the generated XML as part of the solution.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020