Up to this point, we’ve introduced a lot of features available in different versions of Oracle Application Server without providing much explanation of what they do. The following subsections group the main components of Oracle Application Server into three basic categories—core components, application components, and additional components—and describe briefly what these components do.
Remember that this chapter includes only summary descriptions of the components that make up Oracle Application Server. Subsequent chapters will describe these components in greater detail.
The components that make up the core of Oracle Application Server are the Oracle HTTP Server, Oracle Application Server Containers for J2EE, and OracleAS Web Cache.
The Oracle HTTP Server, which is based on the Apache Web Server, provides the services needed to handle incoming HTTP requests and can serve as a proxy server. Developers can program in languages such as Perl, C, C++, PL/SQL, and Java, and can leverage libraries and frameworks such as BC4J, the XML Developer’s Kit, Java Naming and Directory Interface (JNDI), and JDBC. The Oracle HTTP Server supports Server Side Includes for adding content (such as header or footer information) across all of a web site’s pages. Servers can be clustered in high-availability configurations, and Oracle HTTP Server also supports load balancing, which can couple high availability with scalability. Security support includes OracleAS Single Sign-On and encryption with the Secure Sockets Layer (SSL).
Chapter 5 describes the Oracle HTTP Server in greater detail.
Oracle Application Server Containers for J2EE (OC4J) is a set of J2EE-certified containers executed using any standard Java Virtual Machine (JVM). OC4J provides a JSP translator, a servlet engine, and an EJB container. It also provides other J2EE services to the containers, such as JNDI, JDBC, Java Message Service (JMS), Java Authentication and Authorization Service (JAAS), and Java Transaction API (JTA). OC4J supports clustering, load balancing, and application state replication for web and EJB applications, thus enabling highly available and scalable configurations. OC4J can use Java Object Cache in the OC4J containers.
Chapter 6 describes OC4J in greater detail.
OracleAS Web Cache is a memory cache that speeds the delivery of content to requesters. OracleAS Web Cache can store both static and dynamic pages, as well as parts of pages that are marked with Edge Side Include (ESI) tags. This cache also provides other types of functionality, such as balancing request loads between multiple instances of the Oracle HTTP Server and monitoring the speed at which content is returned to users.
Chapter 7 describes OracleAS Web Cache, as well as the other Oracle Application Server caches (Java Object Cache and Web Object Cache), in greater detail.
Clients can invoke these either dynamically or statically.
Other standards supported include publishing and query with UDDI and typed and untyped SOAP messages with SOAP header access via an application programming interface (API). A dynamic WSDL tester allows you to create web-based clients and simplify the testing of Web Services during development.
Chapter 11 describes Oracle Application Server Web Services in greater detail.
OracleAS TopLink is an object-relational persistence tool used to store Java objects and EJBs in relational database tables. The visual mapping interface allows developers to define how Java classes are mapped to database schema. Thus, a Java developer using OracleAS TopLink doesn’t need to write SQL calls. Using the visual mapping tool, the developer can usually handle database schema changes without needing to recode the Java applications. The mapping tool provides graphical views of relationships, queries, locking, caching, sequencing, and other areas of interest that enable performance tuning.
Chapter 8 describes OracleAS TopLink in greater detail.
Oracle JDeveloper is a part of Oracle Developer Suite, rather than of Oracle Application Server itself, but it can create the Java applications that are deployed on an Oracle Application Server platform. Oracle JDeveloper was introduced by Oracle in 1998 to enable the development of basic Java applications without the need to write large amounts of code. At the core of Oracle JDeveloper is an advanced application development framework. Oracle JDeveloper provides numerous wizards that create Java and J2EE objects and project types. Some wizards in Oracle JDeveloper include:
Database development features include various Oracle drivers, a Connection Editor to hide the complexity of using the JDBC API to establish connections, database components to bind visual controls, and a SQLJ precompiler for embedding SQL in Java code (which you can then use with the Oracle database).
Oracle Application Server comes with a limited-use license for Oracle JDeveloper. The development tool is packaged in the Oracle Developer Suite.
Chapter 8 describes Oracle JDeveloper in greater detail.
Oracle Application Server Forms Services provide data handling, navigation, database access, and database validation for Oracle Forms applications. These services allow Oracle Forms to run in an N-tier web environment.
Forms deployed to Oracle Application Server are developed using the Oracle Forms Developer, an interactive development tool that is part of the Oracle Developer Suite. Oracle Developer allows you to define applications by defining values for properties, rather than by writing procedural code. Oracle Developer supports a variety of clients, including traditional client-server PCs and Java-based clients. The Forms Builder includes a built-in JVM for previewing web applications.
Chapter 9 describes Oracle Application Server Forms Services in greater detail.
Oracle Application Server Reports Services enable the rapid deployment and publishing of web-based reports. Reports can also leverage the Oracle Application Server Single Sign-On capabilities and can be embedded as portlets in OracleAS Portal.
Reports are created using the Oracle Reports Developer, a part of the Oracle Developer Suite. Data can be formatted in tables, matrixes, group reports, graphs, and combinations. You can achieve high-quality presentation using Cascading Style Sheets (CSS), an HTML extension. Using OracleAS Reports Services, XML-based reports can be exchanged via HTTP, and paper-based layouts can be deployed over the Internet using PDF format.
The components described in the following subsections provide extended functionality that is an important part of Oracle Application Server. These components relate to specific areas of IT, such as business intelligence and integration, or provide capabilities that can be used by developers, such as OracleAS Portal or the Oracle Internet Directory.
OracleAS Portal, packaged with Oracle Application Server, provides an HTML-based tool for developing web-enabled application interfaces and content-driven web sites. Portal applications can be developed using wizards in a WYSIWYG portal development environment. Using this environment, you can create and deploy static and dynamic portal content. Users can be granted access to the environment to create their own customization. For example, you can grant an OracleAS Portal user permission to choose which content areas and links appear in his portal pages.
Java or PL/SQL developers may wish to leverage the functionality of OracleAS Portal without having to use the Portal Development environment. For such power developers, Oracle also provides a Java and PL/SQL Portal Development Kit for custom portlet development or application integration.
Portals are deployed as an integrated service in Oracle Application Server and can use directory services, the OracleAS Web Cache, J2EE services, and business intelligence services provided by OracleAS Reports Services and OracleAS Discoverer.
Chapter 13 describes OracleAS Portal in greater detail.
OracleAS Discoverer is a business intelligence tool used for ad hoc queries and user-generated reports. OracleAS Discoverer also provides an interface to relational online analytical processing (ROLAP) by leveraging analytic features present in the Oracle database and as of 2004, also provides an interface to the Oracle OLAP Option. Included in Oracle Application Server are:
- Discoverer Plus
A Java-based browser client that can be used to generate ad hoc queries, reports, and graphs
- Discoverer Viewer
- Discoverer Portlet Provider
OracleAS Discoverer can leverage the Oracle Application Server Single Sign-On capabilities and can also export workbooks to Oracle Reports Developer for deployment in OracleAS Reports Services.
OracleAS Discoverer has an End User Layer (EUL) that is metadata-driven, enabling business definitions to hide and map to underlying technical descriptions. The EUL is set up and maintained via Oracle Discoverer Administration Edition, a part of the Oracle Developer Suite. Wizards guide the administrator through the process of building the EUL. In addition to managing the EUL, administrators can put limits on resources available to analysts monitored by the OracleAS Discoverer query governor.
Chapter 12 describes OracleAS Discoverer in greater detail.
The Oracle Internet Directory provides users a means of connecting to an Oracle server without requiring a client-side configuration file. The Oracle Internet Directory is a Lightweight Directory Access Protocol (LDAP) directory that supports the Single Sign-On capability of Oracle Application Server.
Oracle Workflow provides a graphical workflow builder that facilitates the modeling of business processes. A rules-based engine and business event system is stored in an Oracle database. Messages can be transmitted via Advanced Queuing (AQ), Oracle Net, HTTP, or HTTP using SSL (HTTPS). Oracle Workflow provides key capabilities needed to deploy Oracle Application Server InterConnect, described in the next section.
Chapter 15 describes Oracle Workflow in greater detail.
Oracle Application Server InterConnect provides a heterogeneous application integration platform through logic and services. Deployed in a “hub-and-spoke” manner, Oracle Application Server leverages Oracle Workflow and Oracle AQ to provide a message broker infrastructure. AQ enables asynchronous messages between Oracle databases with adapters available to extend support to other message types and applications. Content-based publish-and-subscribe solutions can be deployed using a rules engine to determine relevant subscribing applications. As new content is published to a subscriber list, the rules on the list determine which subscribers should receive the content, thus efficiently serving the needs of different subscriber communities.
OracleAS InterConnect includes a design-time Integrated Development Environment (IDE), adapters, a metadata repository, a management infrastructure (used with Oracle Enterprise Manager), and SDKs (for writing custom adapters, transformations, and IDE extensions). Adapters are available for HTTP, HTTPS, AQ, Oracle database, FTP, MQSeries, CICS, SAP, PeopleSoft, Siebel, JDEdwards, and CICS.
Chapter 15 describes OracleAS InterConnect in greater detail.
Oracle Application Server ProcessConnect is new to Oracle Application Server 10g. Using wizards to create a hub-and-spoke deployment model, it’s designed to make business process integration feasible. OracleAS ProcessConnect includes a modeling tool, a metadata repository, and adapters. These adapters are based on the JCA specification and enable connections to technology (such as Web Services), packaged applications (e.g., JD Edwards, PeopleSoft, SAP, and Siebel), and legacy systems.
Chapter 15 describes OracleAS ProcessConnect in greater detail.