Java ES is an integration of discrete software products and components into a single software system. This integration is facilitated by a number of system-level features, as listed below:
All components are synchronized on a common set of shared libraries.
All Java ES components are installed using a single installer.
All Java ES components can share an integrated user identity and security management system.
All Java ES components have a common monitoring framework.
These features are described in subsequent chapters of this book. The focus of this section is to introduce the components that are integrated into Java ES. These system components can be grouped into three main categories, as shown in the following figure.
The components provide services as follows:
System service components. These components provide the main Java ES infrastructure services that support distributed enterprise applications.
Service quality components. These components enhance the availability, security, scalability, serviceability and other components of system service components and distributed application components.
Shared components. These components provide the environment in which many system service components and service quality components run.
For a list of Java ES components, see Appendix A, Java ES Components.
A number of Java ES components provide the main services that support distributed software solutions. These system services include portal services, identity and security services, web container services, J2EE application services, and persistence services.
The system service components that provide these distributed services and the services they provide are listed alphabetically and briefly described in the following table. Each system service component is a multithreaded server process capable of supporting a large number of clients. For more details on each component, see System Service Components.
Table 1–1 Java ES System Service Components
In addition to the system service components shown in Table 1–1, Java ES includes a number of components used to enhance the quality of services provided by system service components. Service quality components can also enhance custom-developed application services. The service quality components fall into the following categories:
Availability components
Access components
Monitoring components
Availability components provide near-continuous uptime for system service components and custom application services. The availability components included in Java ES and the services they provide are shown in the following table. For more details on each component, see Availability Components.
Table 1–2 Java ES Availability Components
Access components provide front-end access to system services, often secure access from Internet locations outside an enterprise firewall. In addition to providing such access, many provide a routing and caching function as well. The access components included in Java ES and the services they provide are shown in the following table. For more details on each component, see Access Components.
Table 1–3 Java ES Access Components
Java ES includes a new monitoring feature that provides real-time system status and customizable monitoring jobs. Monitoring is implemented by the Sun Java System Monitoring Console product component, which is supported by the Sun Java System Monitoring Framework shared component. For more information, see Monitoring Components.
Java ES includes a number of locally installed shared libraries upon which many system service components and service quality components depend. Java ES shared components provide local services to Java ES product components running on the same host computer.
Shared components are often used to provide portability across different operating systems. Examples of Java ES shared components include: Java 2 Platform, Standard Edition (J2SE), Netscape Portable Runtime (NSPR), Network Security Services (NSS), Java Security Services for Java (JSS), and so forth. For a complete list, see Shared Components.
Shared components are installed automatically by the Java ES installer depending on the system service and service quality components that are being installed.