Use JMS and JCA to implement the solution between applications

The traditional enterprise information system integration method is a point-to-point tight coupling integration. In this integration method, each system needs to know the structure of the Integrated System and the communication mode between them, and a system change will affect other related systems, if a system is replaced, all integration interfaces must also be replaced.
　　
Even worse, because the business logic of an enterprise is distributed in all these information systems, this decentralized business logic is not easy to manage and monitor, nor is it easy to improve the business process. Therefore, enterprises need to integrate the business process and the system's enterprise application integration architecture to achieve the solution between the business logic and the application system.
　　
Business Process Integration
　　
Business processes are usually driven by events, which are activities caused by user behavior, software, and time. Business Process Automation that spans multiple heterogeneous application systems is usually called Business Process Integration.
　　
Solution Application
　　
As part of the Business Process Integration Strategy, the solution requires that different systems or components do not have to understand other systems or components integrated with them. Solutions include:
　　
Eliminates point-to-point communication and message transmission;
　　
Minimum dependence on the message data structure;
　　
Centralized management of business process flows;
　　
Publish/subscribe message transmission
　　
The J2EE Application Server architecture is an event-based application integration architecture. In this integration architecture, message transmission in the publishing/subscription mode is the core component, it eliminates the point-to-point message transmission and communication methods to provide the first-layer solution. Publish/subscribe message transmission is an asynchronous message transmission technology that allows message producers and consumers to communicate with each other and allow multi-to-many communication. This solution eliminates the need for both parties to know who the other party is. In Java Message Service (JMS), different topic domains, time types, or other endpoints are called as topics. The topic is similar to the queue concept except for the point-to-point feature. Enterprise Integration architecture can design different themes based on the event type, which means that the message publisher and subscriber can be added without learning about other components. The reduction of publishers and subscribers is also transparent. This advantage is that it provides a new system with an opportunity to present its capabilities. It can run concurrently with the old system, until it can completely replace the old system.
　　
In the message transmission mode of publishing/subscription, failure of one system will not bring too much impact to other systems, because continuous messages and persistent subscribers can queue messages to guide the faulty system to restore normal.
　　
JMS makes publishing/subscription simple and standardized. JMS already exists in the Application Server Based on the J2EE 1.2 standard. Therefore, it does not need to use a dedicated message passing system interface.
　　
Adapter
　　
An adapter is a configurable component that converts the event format and content into an even application. The adapter provides encapsulation of data formats. For example, if a system provides a CSV (Comma Separate Value) file, multiple adapters can be used to convert it into XML standard files for the enterprise, and then publish. The adapter further decouples the application so that they do not depend on the specific data format.
　　
Connector
　　
A Connector is a source adapter based on the Java Connector Architecture (JCA: Java Connector Architecture) and is defined in J2EE1.3 specifications. JCA defines standard APIs for enterprise information systems that can be integrated with J2EE1.3 application servers for software vendors. The JCA Connector provides an important capability that enables the J2EE application server to integrate any enterprise information system using the JCA adapter, greatly simplifying the integration of heterogeneous systems. With JCA, enterprises only need to purchase an application system adapter based on the JCA specification to deploy their applications on the J2EE server, you can integrate with the J2EE application server without writing any code.
　　
Workflow
　　
Currently, a workflow has many different names, but its basic activity method is the same as that of a State Machine. System Designers configure different statuses and their migration conditions for the business process. Event-triggered workflow migration from one status to another. State migration itself is an important business process event. Workflows provide the following advantages:
　　
Integrates business process streams and stream events, and increases the impact on publishing/subscription;
　　
When changing the definition of the business process, the impact on the existing system is reduced;
　　
The integration is changed to the definition of the business process, rather than the exchange of data between systems.
　　
Workflows are not yet part of the J2EE specification. Only dedicated workflow management software can be used to integrate the workflow management system with the J2EE server.
　　
Conclusion
　　
All systems must be fully integrated at the end. Traditional tactical integration methods ultimately result in a lot of time, money, and lack of flexibility in the system. Using the business process management architecture to decode even applications and integrating business processes is a better solution. A J2EE-based integrated architecture enables centralized management of business process flows and the use of JMS and JCA for application coupling. Through the solution application, the integration of business processes can greatly reduce costs, provide flexible business process flows, and improve the integration advantages of enterprises.