5 Performing Back-End Integration
The last challenge to establish a network service using J2EE is to connect to the background, such as database, traditional system, and other business partner software systems.
5.1 Database Connection (Database Connectivity)
For the traditional database connection, developers can choose the following API:
Translator Note: The following definitions are already very old, please see the original text in order to keep integrity:
The JDBC API is a relational database API used to access any SQL-compliant database. JDBC isolates you from the specific protocol and syntax of a particular database, yielding more portable code. JDBC is a widely accepted standard, and a myriad of JDBC drivers are Available for Download Today.
SQL / J IS A Standard for Embedding SQL Logic Directly Into Java Code. This is Somewhat Analog to HOW JSP Components Interlace Java Code forin HTML Tags.
5.2 Connection of traditional systems (Legacy System Connectivity)
Translator Note: Because these and domestic situation is not very relevant, I will go to translate, I am interested, please see the original text:
Connecting to existing systems has historically been one of the most challenging and burdensome tasks of creating any enterprise deployment. Most enterprises comprise a hodgepodge of existing systems such as SAP R / 3, Siebel, i2, and custom systems. Integration has been a manual task , because there are very few adapters available for existing systems. ISVs have been required to write custom adapters for every platform, but this lack of a standard platform has left little or no incentive for ISVs to do this.
The J2EE Connector Architecture (JCA) is an industry movement that is spawning a marketplace of adapters to existing systems. Using the JCA, you can download or purchase an off-the-shelf adapter to connect to an existing system. You can also write your OWN, IF No Such Adapter EXISTS. THESE Adapters Can Run in Any J2EE-Compliant Environment.
With the JCA, you gain the benefits of the "write once, run anywhere" paradigm - write the adapters once, and run them in any J2EE environment For ISVs of existing systems (such as SAP), this creates a unique opportunity for them. to solve integration problems for their clients. Indeed, adapters are already being developed as we speak, and this is what makes the JCA so exciting for end developers.5.3 business partner connections (Business partner Connectivity)
The last type of background system we might want to connect to a network of business partners. These business partners use the same global XML standard to render themselves, we can use them when publish our own network services. That is, use UDDI as a registry of network services, WSDL as a description of network services, SOAP, and EBXML to process business things.
Your EJB component layer can use a series of APIs starting with JAX to call our business partners' web services.
Use Java API for XML Registries (JAXR) to find network services in the UDDI registry
Use the Java API for XML RPC (JAX / RPC) to give an external network service request to a RPC response.
Use Java API for XML Messaging (JAXM) to send SOAP or EBXML messages to external network services
Use Java API for XML Parsing (JAXP) and Java API for XML Binding (JAXB) to convert Java data (such as data imported from the database) for the XML format for partners. You can use the same API to convert the received XML data to the Java data structure or use XSLT conversion to convert Schemas.
Using the J2EE Network Services Architecture Java Standard API, we can build a powerful cross-platform system that can be shared with our partners, thereby implementing a end-to-end network service solution Figure 7 shows this architecture.
Figure 7 uses JAX * API to call commercial network services
6 Conclusion
In this article, we review how to use J2EE to establish network services. The most important benefit to establish network services using J2EE is to use the existing J2EE basic architecture to complete 70% to 90% of network service system features. Developers reserved all the benefits of the best development J2EE system standards and continued to master J2EE techniques. A network service architecture has great flexibility. Developers can consider high-rise architectures before implementing specific functions, and you can use private components that are best suited for corporate demand or components that are most suitable for corporate needs.
Developers using J2EE network service architectures can continue to pay attention to the standards and functions that are expanding. Developers can now utilize existing existing such as servlets, JSP, EJB, and JAXP, and many SOAP, WSDL, and EBXML tools. The more advanced JAX Series API that is about to be introduced will further simplify network services and provide an increase in dramatic development capabilities. The continuous development of standards and private components will further strengthen their ability to develop strong solutions.
Note:
Translation: Cao Yonggang, some contents have an exceptional selection and access to the author's understanding, time limited, there may be wrong or missing places, please refer to the original text.
In addition, due to the timing of automatically generated from Word, the sequence section is re-numbered during the block paste, and the pictures are not, the wood is already a boat, no longer pay, hopes to pay attention! The chapter number may be wrong. However, the reading does not affect the content from head to tail (1-5). Source file comes from http://www.theserverside.com/resources/article.jsp?l=webservices-dev-guide:
Developer's Guide To Building Xml-Based Web Services with the Java 2 Platform, Enterprise Edition (J2EE)
By James Kao June 2001, Prepared for Sun Microsystems, Inc.
