J2EE e-government portal system
Banq@jdon.com)
The government is the largest information owner and the largest information technology in the whole society, effectively utilizing information technology, by establishing a truly effective, scalable e-government system, can help the government to more diligently, streamlined, integrity and Efficient direction development. E-government will realize the four-way direction of government applications: information unification, office automation, government publicization, scientific science, through one-stop management and service, enhance government department functions, office efficiency, better for the country and people service.
The entire e-government system can be divided into two major parts: integrated portal systems and government affairs systems. The former is a window for the public, which is convenient for enterprises or citizens through the portal system; through the latter can establish an efficient cooperation coordination system for automatic operation of the government within the government.
The e-government system is a very complex system, involving many features and specific requirements, the more this huge project, the more important architectural design, including those hundreds or even thousands of specific functions into an overall framework, so e-government The system can become a scalable, dynamically expandable, and maintainable and controllable benign systems.
demand analysis
The portal system is the basis of the entire e-government system, which reflects the basic idea of the government for the people. The demand of society droves the operation of the government machine, from the structural diagram of Figure 7-1, the portal system can be found in the entire e-government system importance:
Figure 7-1 Structure of Electronic Administration System
Figure 7-2 The door-to-door system is the forefront of the entire e-government. The government can release unidirectional information through the news content management system. This is the whole society; the public will require information on government services to interact by online Submit, use a special interface system to submit this service request to a special sector system, need to be coordinated between multiple flat or upper and lower levels, will be tracked by a special coordinated supervision management system, one of the entire system design goals Guaranteed that every society requests government services can be locked at any time, which is similar to logistics company's goods, which links are in a certain time, in what state, this information can be queried by the public by the public, thus Go to the social supervision of government work efficiency.
As a government leadership decision-making body, it is possible to understand some policy implementation and feedback from the government network system, providing good data support for policy amendments and auxiliary decisions. Through the decision-making support system, the decision-making leaders can liberate from the transactional work, and more time and energy will be used to think and design the decision-making of social progress, and it can also find and correct some maybe unrealistic policies. policy.
The government government system belongs to a constantly dynamically expanded system, the core functional part of the entire system, and the portal system is the "interface performance" section of the government private network system, which is very compliant with the application requirements of the current B / S mainstream technology.
Therefore, from the surface, the portal system and government government belong to two different systems. In fact, they can be included in a unified framework system. The main ideas is that the portal system is mainly designed by Web technology, and government government affairs The system is designed as a functional component system.
Administrative administration as a functional component system, its system needs are dynamic, and can be done in accordance with the government's specific needs, and the portal system is required to analyze the portal system.
The portal system is a website system that provides efficient access to customized information or various resource applications. In traditional portal, information is rich and complicated, but the user requirements of access portals are different, so how to provide an effective Technical means allows users to quickly and easily access or use the information or resources they need through the website. This new demand causes the proprietary portal Portal system.
The demand for the use of e-government integrated portal systems is as follows:
Figure 7-2 Use case requirements for portal systems
In such a need, the portal system needs to help companies or citizens can easily customize their own information content, and provide a window that is online, enabling enterprises or citizens to implement some administrative approval services, government procurement, online taxation through this window. And online business, etc. The portal system provides a rich and complex content channel, such as news announcement, government announcements, institutional introductions, news activities, legal system announcements and modifications; interactive features include full-text search, electronic forum, feedback, and online services, etc. In the function, it is not necessary to need each user, which requires these content channels or interactivity functions provided by the portal to be customized by the user, achieving the user's own autonomous management, which is a major functional requirement for the portal system.
Since the portal system belongs to the social mass and government's exchange interface, the public needs the portal system to better serve themselves, and the government government system requires the portal to push their service functions to the society, driven by these two needs, portal The content of the system will become very complex and chaos, how to effectively manage and monitor these content will also be a main feature requirement for the door care system.
In addition to the above two feature requirements, there is also the following important factors to consider the following important factors:
How many users have you? Which types of users are all types of users, and the user's role definition; user access.
How many languages do you need to support?
What kind of clients need to support? PC browser, mobile phone movement or other?
What kind of media types need to support? Sound, graphics, and real-time images?
How many content channels?
If you connect an existing resource? Servelt, HTTP, SOAP, CORBA, etc.
Why use J2EE technology
J2EE has been widely used as a new type of mature distributed computing technology, which has a flexible selection and implementation of scalability, scalability, scalable framework system.
There are two main benefits of using J2EE technology to implement e-government systems: high security and diverse choices.
The first is to meet the safety requirements, and the e-government system is subject to a part of the Internet, and the security of its system should be primarily considered.
The implementation of safety requirements is multifaceted, first is operating system and communication, by modifying the operating system kernel implementing the country's own encryption system is a relatively good program, then it is obvious that the Linux operating system based on open source-based Linux will be possible. A large number of use in an e-government system, while Java is a cross-platform secure language, so J2EE technology can meet the requirements in security.
The e-government system will involve a large number of terminals and PCs and servers, including old systems and new systems, Windows and Linux or UNIX, how to use these existing resources, implement system seamless operation, cross-platform language Java is undoubtedly the first choice, which saves investment and reduces costs.
The e-government system is a complex comprehensive system, and there is a large number of old system resources that need to be integrated. In this huge system implementation, it may encounter unprecedented issues, and the technology is special to solve these problems. However, there is only a variety of technical tools, providing a variety of solving problems, just like a hardware toolbox with a variety of different screwdrivers, wrenches, etc. With these rich and diverse, various technical tool support can help We solve various problems, while the Java system has developed into a standard system for open source. In this system, there is a large number of software tools, which have a large number of software tools every day. These undoubtedly provide strong support for the construction of e-government systems. .
In summary, the high level of security and diverse choice is to use J2EE to build an e-government system's greatest advantage. The government as information technology consumers must settle their own active status, which is also a kind of Safety considerations. Analysis and comparison of existing J2EE portal technology
Apache jetspeed
JetSpeed is an open source project organized by apache (http: // jakarta.apache.org/jetspeed/), IBM's WebSphere Portal Server is based on JetSpeed for secondary development.
In the need for the customability of the portal, the portal component concept portlet is introduced. The portlet is a pluggable component, and the portlet has various definitions, JSPEED is submitted, the JSR-168 portlet API Specifications is defined as the portlet:
Portlets are a web component that can be managed by the container, which can generate dynamic content. Portlets can be easily inserted and run in a web application, portlets are a combined page that is designed to aggregate a large amount of content, for example: according to different users, different instances can be generated, and these instances are based on users The settings contain different contents, that is, to satisfy the user's ability.
In order to achieve effective management and monitoring of portal content, JetSpeed's important content component slide introduces the concept of domain and namespace, controlling all resources, in SLIDE, Domain is a series of Namespace aggregates, it is similar The "/" root directory in the system, Domain can control the access rights of Namespace in which registered Namespace, and execute management work for initialization and connection of Namespace.
Namespace is a self-independent container that cannot contain or connect to other Namespace, each application system can be a Namespace, NameSpace contains independent data and security access mechanisms for these data.
Although JetSpeed provides a wealth of portal technology, it is more customizable, and its important content component SLIDE is also more difficult to understand. Its security control framework is not integrated with General J2EE, all of which are caused by JaaS. The difficulty of secondary development is carried out on the basis.
Liferay
Liferay (http://www.liferay.com) represents a complete J2EE application, using technologies such as Web, EJB, and JMS, especially its front interface part uses Struts framework technology, XML-based portlet configuration files can be freely dynamically Extended, using Web Services to support some remote information acquisition, use APAHCE Lucene to implement full-text search function.
Liferay's disadvantage is that it lacks a simple and clear architectural architecture design, and Portlet is designed to be more messy. It has certain difficulties in the second development.
OFBIZ
OFBIZ (http://www.ofbiz.org/) is a more influential open source software. OFBIZ is a large software framework that tries to work with J2EE framework technology and drive, its core is three engines: physical engine, service service Causes and workflow engines, the biggest advantage of OFBIZ is its convenient entity engine that can quickly develop hundreds of data sheets.
The OFBIZ service engine provides specific forms of implementation of workflow, SOAP, so that users can use the technologies you need to use directly through service engines, similar to a dynamic convenient API library.
OFBIZ also has its own security rights control framework, which can be bound to each service. The disadvantage of OFBIZ is that since it tries to build a large frame system that is unparalleled, it will inevitably lead to the complexity of its architecture organization, and try to carry out the overall secondary development of the whole; and OFBIZ is mainly a web structure. The system is insufficient in transaction, security, and distributed computing. Of course, some of the Ofbiz's excellent modules and components are worth learning and direct use.
Some of these portal software, their common defects are each built a user security permission control framework. Once any of the security frames used, the framework of the entire system is forcibly fixed, and flexible expansion and changes cannot be performed. And they are not integrated with the current JAAs mechanism.
In practical applications, user security rights control should be an independent, but also with the specific application system-related dynamic scalable system, by using J2EE's JAAS mechanism, you can implement single-point landing (SSO), access Flexible configuration dynamic system.
Architecture design
Comprehensive existing portal design concepts, fully architecture of this project in the J2EE standard framework, fully utilize J2EE overall technical framework resources, and build this project into a distributed cluster environment, a flexible large system that can be dynamically expanded.
The idea of absorbing the Domain tree structure in Apache Slide can think of the portal is a collection system under the control of the tree structure, as shown in Figure 7-3:
Figure 7-3 Tree structure control of the portal system
In Figure 7-3, whether it is a static news content information, or a dynamic interaction function such as an online office, they all belong to a specific resource resource, connecting the resource to the entire portal system by an Node that is a node, so that resources can be inserted into the entire portal system. These resources can be easily managed through the tree structure.
Solving the idea of Domain and Namespace in Apache Slide, you can think that the current entire application system is a Domain, if this application is a portal system, the Web directory structure of the Web application layer is as follows.
Portal
|
| --- Web-INF
| ---- Admin ??
| ---- Forum
| ---- Taxation
| --- Account
In the above schematic, the root directory "/" is a Domain. In this root directory, there are various resources, and Forum represents the forum function; taxation represents the online tax-related service; Account Represents personal account resources, so in the web layer, resources are positioned by relative path PATH, such as / forum Located to the forum resources under this Domain, in fact, relative paths are also a URI (unified resource locator).
Since the web container implements the role access control, you can flexibly set access to a path PATH in Web.xml, so this actually solves the security rights control problem of resources.
The architectural diagrams of the entire system are as follows:
The tree structure in the portal system is similar to an organization map, which belongs to the height control section of the system, and the access management of the tree structure will be implemented in the service layer.
In order to meet the amount of huge visits, it will have a powerful processing function through J2EE, and the J2EE will have a powerful processing function. Take the JBoss server as an example:
Unified user management and security rights mechanism
By using JAAs (Java Authentication Authorization Service: Java authentication and authorization API) provided by J2EE containers, JaaS is a J2EE server to help application systems implement security features. When the developer of the application system implements the LoginModule API, then the J2EE container performs LoginModule Interfaces, relationships between interfaces and specific implementations, J2EE containers will combine specific JAAS functions in conjunction with specific application systems. Access Permissions (ACL) will use the security mechanism for J2EE containers, and there is a corresponding criterion on the Web layer and EJB layers to implement access to resources, which can be easily allocated by simple container ACL configuration. Control, at the same time, the security configuration work and security implementation can be cut off, prevent fraud.
Establish a unified LDAP-based centralized user data system so that the entire system user's single landing (SSO), that is, only one point that can log in to the entry, it is common to all requests. Single landing ensures that users can access the resources that can be accessed, if there is an unauthorized request request to access the protected resources, this request will automatically be directed to the corresponding verification point for login verification.
System integration and communication plan
Considering that the components of the entire e-government system are complicated, new and old technical standards are inconsistent, so there are many kinds of data integration schemes, and there are many options according to specific conditions.
Integrated EAI with the original system is integrated by building a middleware infrastructure and several adapters, which allow different backend applications to insert a certain type of public protocol to exchange data.
JMS and JCA
Several specifications have been established in the J2EE environment to achieve this adapter, such as Java Messaging Service (JMS), and Java 2 Connector Architecture (JCA), which are mainly used to integrate J2EE applications with non-J2EE environments. together.
JMS is an asynchronous message system that is mainly to achieve delivery services between message producers and message users, and the message system provides the advantages of many other distributed object computing models. It encourages "loose coupling" between message generator and users, with a high degree of transaction between them. For the user, it does not care when to generate a message, whether the generator is still in the network and when the message is generated. This allows for establishing a dynamic, reliable and flexible system. The entire subsystem can be modified without affecting the rest of the system.
The Java 2 connector architecture defines a safe, transactional way to make J2EE applications and non-J2EE environments (usually, Enterprise Information Systems, or ESTE) Method of communication. Using the JCA API solution is better than JMS-based solutions and backend coupling; more specifically, the JCA specification can be combined with the sending and processing of messages in the same message exchange or in the same transaction. The processing of EIS is synchronized, so it can be part of a transaction management of J2EE application servers. Therefore, the business process running across multiple backend applications across multiple backend applications across multiple backend applications - the steps performed by these applications are all submitted, or one step is not submitted.
Data exchange based on various protocols
Bie (http://www.brunswickwdi.com/index.pl/bie) is used to help organizations perform data exchange between different operating systems, implement EAI and B2B solutions, which are similar to Microsoft BizTalk, but Compared with two advantages: L ???????? Since Java reaches a real cross-platform implementation of data exchange
L ???????? Open source, suitable for secondary openness
You can use BIE to accept data documents from other applications or other companies and convert them into XML for their own application. Instead, you can also get data from your own application and use Bie in different formats to be used in different formats. No matter which case, the data begins to be a format, then converted into XML via Bie, then you can output data at a completely different format. Whether it is a data source or a data recipient, their data format does not have to be the same, or even the XML format.
BIE is more than just a data exchange server, which also provides powerful graphics service flow control tools. Business analysts draw traffic flow in a similar flow chart to achieve the features required.
Become a standard Web service provider
Once the e-government system is initially installed, the amount of information contained over the entire system will become the most powerful resources in society, how to better serve these resources in society, so that all walks of life fully excavated in their own way. The value of the data information will become the primary issue.
Through Web Services technology, you will be a development trend, such as meteorological information, which is released by the Government Meteorological Department, but almost all news-based websites or portals need local meteorological information, then This service can be provided through Web Services.
A typical web service (Web Services) structure includes three entities: service providers, service brokers, and service needs. They provide three basic functions: running publishing, looking and binding. Service providers create web services and register online services at the service broker; the service broker is responsible for maintaining registration systems for publishing services; service needs are looking for services required by searching for service brokers, and will Service requests are bound to service providers to use specific services.
The e-government system must be a service provider because of its rich and powerful resources and information, these resources and information may be the most local society. It has reason to be the largest Web service provider.
Currently, Web services are in practice and perfect, including security, management or transactions, and other issues are still to be further resolved, but Web services must be included in the planning of the entire e-government system.
Discussion
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Supplement: About the Standard of the Portal portal system has been approved by JSR, instructions see here
