uCosminexus Application Server Overview

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4.1 Application execution environment and application development environment

This section describes the characteristics of Application Server.

Application Server is a base for executing a service (Service deployment). Application Server builds an application execution environment that provides services to a user, while securing performance and reliability. Application Server can also build an environment for developing the applications to be used as services.

The characteristics of the execution environment and development environment of an application are as follows:

Application execution environment
The application execution environment is an environment that is a base for providing services to the user by executing an application.
The following are the two types of businesses that can be executed in the application execution environment:
  • Online business (Online process)
    In this business type, the requests sent from the user through the internet or intranet can be processed at any time. The online business executes an application developed using the Java EE technology. This environment is called the J2EE application execution environment .
  • Batch business (Batch process)
    In this business type, the routine jobs are processed in a batch at a fixed time. You can execute the batch jobs that were earlier executed on a main frame, by using Java, which is an open environment technology. The application that executes the batch jobs developed by Java is called a batch application. An environment that executes the batch application is called the Batch application execution environment.

Application development environment
The application development environment is an environment for developing an application to be operated in the application execution environment. You can build and operate a development environment that provides an overall support to an application operating in the execution environment from the development of the application up to the debugging.

Application Server builds the execution environment of an application compliant with Java EE, which is a standard specification. A server process that has functionality to execute an application compliant to Java EE is called a J2EE server.

The J2EE server provides functionality required to execute a J2EE application developed by the user by following the specifications described in Java EE, such as the J2EE container, J2EE services, and J2EE resources. For example, the J2EE server uses J2EE services and J2EE resources to provide functions such as the transaction management and security management to execute common processes in multiple jobs. When developing an application, you can execute the common processes in multiple jobs without doing any complicated coding, by calling the API provided by the J2EE container, J2EE services, and J2EE resources in the application.

The following figure shows the relationship of an application and the J2EE server.

Figure 4-1 Relationship of an application and the J2EE server

[Figure]

Application Server is an execution environment server base for an application and is centred on the J2EE server. Application Server is located at the center of an information system and it delivers the processes in a business system such as delivering user requests to a database.

The J2EE application is executed on Application Server to provide the services corresponding to the requests from the user. The J2EE application that operates on a J2EE server is developed according to the business contents to be executed.

The J2EE application receives requests from the user, executes the process and returns the result to the user. In addition to this, the J2EE application executes the process by exchanging the data with other systems such as the database and the mainframe and obtaining the required information.

The following figure shows the request process flow in the system centred on Application Server.

Figure 4-2 Request process flow in a system focusing on Application Server

[Figure]

The explanation of the flow in the figure is as follows:

  1. When a user executes a process on the Web browser, a request is sent from the Web browser to Application Server. The request sent from the Web browser is received by the Web server, which is a part of Application Server.
  2. The J2EE application corresponding to the request from the user is executed on Application Server. The J2EE application consists of a program (Servlet or JSP) to receive the requests sent from the Web server and a program (such as Enterprise Bean) to execute the business processes.
  3. The J2EE application accesses the database and other systems to process the request from the user, as and when required.
  4. When the business process is complete, a response is sent to the Web browser through the Web server. A window to be displayed on the Web browser is generated by a servlet or a JSP in the J2EE application. The generated contents are displayed as the process contents on the Web browser operated by the user.

Application server has safe operability and high fault tolerance and you can build a system that can be executed with excellent performance. In addition to this, you can build and operate an efficient system with functions for the smooth execution of operations.