Java EE e-Government portal system

J2ee

The government is the largest information owner and the largest information technology user in the whole society, the effective use of information technology, through the establishment of a truly effective and scalable e-government system, can help the government to more diligent, streamlined, clean and efficient direction. E-government will realize the Sihua direction of the application of government affairs: information Unification, office automation, Government affairs openness, scientific management, through one-stop management and service, to enhance the functions of governmental departments, office efficiency, and better serve the country and people.

The whole e-government system can be divided into two parts from the demand: Integrated portal system and government administration system. The former is a window to the public, through the portal system to facilitate business or public affairs, through the latter can be within the government to establish a information-sharing, workflow automatic operation of an efficient coordination system.

E-government system is a very complex and complicated system, involving many functions and specific requirements, the more such a large project, the more the need for an overall architecture design, those hundreds of or even thousands of specific functions into a general framework, so that e-government system can become a scalable, dynamic expansion, A benign system that can be maintained and controlled.

Demand analysis

The portal system is the foundation of the whole e-government system, embodies the basic idea that the government serves for the people, the social demand drives the government machine's operation, and the importance of the portal system in the whole e-government system can be found in the structure diagram of Figure 7-1:

Fig. 7-1 Structure Chart of e-government system

Figure 7-2 in the portal system is the most front-end of e-government, the government can through the news content management system to carry out one-way information dissemination, which is for the whole community; The public will need information on government services to be submitted through interactive functions on the Internet, This service request is submitted to a dedicated departmental system through a specialized interface system, need to be in a number of peer or subordinate coordination, will be coordinated by the specialized management system tracking, one of the whole system design objectives is to ensure that every social request for government services can be traced to the information at any time, which is similar to the logistics company's goods, The goods at a certain time in which link, in what state, these information can be immediately by the community to find out, so as to the efficiency of the Government's social supervision role.

As a government-led decision-making body, it is possible to understand the implementation and feedback of some policies from the administrative network system so as to provide good data support for policy revision and supporting decision-making. The decision support system can liberate policy leaders from transactional work, devote more time and energy to thinking and designing decisions to promote social progress, and can detect and revise some possible unrealistic policies in time.

The government affairs system belongs to a continuously dynamic expansion system, is the core function part of the whole system, and the portal system is the "interface performance" part of the administrative network system, so the composition structure conforms to the application demand of the B/s mainstream technology now.

So, on the surface, the portal system and government affairs belong to two different systems, in fact they can be integrated into a unified framework system design, the main idea is: The portal system is mainly designed by Web technology, and the government administration system is designed as a functional component system.

Government administration as a functional component system, its system needs are dynamic, can be based on the specific needs of government components, the following first of the portal system needs analysis.

Portal system is to provide customized information or a variety of resource application systems for effective access to the Web site system, in traditional portals, the information is rich and complex, but access to the portal user requirements are different, so how to provide an effective technical means, Enabling users to quickly and conveniently access or use the information or resources they need through a Web site, this new demand prompts the emergence of a proprietary portal system.

Overall the e-Government integrated portal system use case requirements are as follows:

Figure 7-2 Use case requirements for portal systems

In such a demand, the portal system needs to help enterprises or the public to facilitate the customization of their own relevant information content, while providing a window to do business, so that enterprises or citizens through this window to achieve some of the administrative examination and approval services, government procurement, online tax and online business and so on.

The portal system provides rich and complex content channels, such as bulletin boards, agency briefings, news campaigns, legal system announcements and revisions; interactive functions include full-text search, electronic forums, feedback and online services, which are not required by every user, This requires the portal site to provide these content channels or interactive features are customizable by the user to achieve their own self-management, customization is a portal system a major functional needs.

Because the portal system belongs to the communication interface between the public and the government, the community needs the portal system to serve itself better, and the government affairs system needs the portal to push its service function to the society, in which the contents of the portal system will become very complex and chaotic, How to manage and monitor these contents effectively will also be a main function requirement of the door guard system.

In addition to the above two functional requirements, the following important factors need to be considered:

How many users are there? What are the types of users, the user's role definition, and the user's access rights.

How many languages do I need to support?

What kinds of clients do you need to support? PC Browser, mobile phone or something?

What kinds of media types do you need to support? Sound, graphics, and real-time images?

How many kinds of content channels are there?

If you are connecting to an existing resource? Servelt, HTTP, SOAP, CORBA, and so on?

Why to use the Java technology

As a new mature distributed computing technology, Java-EE has been widely used in many fields, and its scalability and extensibility frame system has brought flexible choice and realization for application system.

The use of Java-EE technology to achieve e-government system has two main benefits: a high degree of security and a variety of choices.

The first is to meet the security requirements, e-government system because of the state secrets, as a part of the Internet, the security of its system should be the primary consideration.

Security requirements are multifaceted, first of all, operating systems and communications, by modifying the operating system kernel to implement the country's own encryption system is a better solution, then it is clear that the Linux operating system based on open source code will probably be used in a large number of e-government systems, Java is a Cross-platform security language, so the technology can meet the security requirements.

E-government system will involve a large number of terminals and PCs and servers, including the old system and new systems, Windows and Linux or Unix have, e-government system how to use these existing resources to achieve seamless operation of the system, Cross-platform language Java is undoubtedly the first choice, so as to save investment, Reduced costs.

E-government system is a complex and comprehensive system, there is also a large number of old system resources that need to be integrated, and in the implementation of this large system may encounter unprecedented problems, technology as a tool to solve these problems, but only the diversification of technical tools to provide a variety of problem-solving possibilities, It's like a hardware tool box that offers a variety of screwdriver types, wrench, and so on, with these rich and diverse, each has the characteristics of technical tools to help us solve a variety of problems, and the Java system has developed into an open source code of the standard system, in this system, every day is born a large number of rich, the characteristics of the software tools , these undoubtedly provide a strong support for the construction of e-government system.

In short, a high degree of security and diversification of the choice of the use of Java EE to build the biggest advantage of e-government system, the government as a consumer of information technology, it must be in a variety of choices of the active status, which is in itself a security consideration.

Analysis and comparison of existing Java-EE portal Technology

Apache Jetspeed

Jetspeed is an open source project of the Apache (http://jakarta.apache.org/jetspeed/) organization, and IBM's WebSphere Portal server is based on Jetspeed for two development.

To meet the requirements of portal customization, the introduction of the portal component concept Portlet,portlet is a pluggable component, with various definitions of portlets, Jetspeed in the submitted JSR-168 portlet API The specifications defines the Portlet as follows:

A portlet is a Web component that can be managed by a container to produce dynamic content. Portlets can be easily inserted and run in a Web application, and the portlet is a composite page designed to aggregate a large amount of content, for example: the same portlet, depending on the user, can produce different instances, which contain different content based on user settings, That is to meet the customization of the user.

In order to realize the effective management and monitoring of the portal content, the important content component of Jetspeed slide introduced the domain and namespace concepts, the tree structure control of all resources, in slide, domain is a series of namespace aggregation, It is similar to the "/" root directory in the file system, where domain can control the access rights of the namespace registered in it and perform administrative tasks such as initialization and connection of namespace.

Namespace is a self-contained, entity-content container that cannot contain points or connections to other namespace, and each application can be a namespace,namespace that contains independent data and a secure access mechanism for that data.

Jetspeed provides a wealth of portal technical features, but its customization is poor, its important content component slide is also more difficult to understand, its security control framework and general Java EE Use Jaas does not merge, all these have created on its foundation two times the difficulty of development.

Liferay

Liferay (http://www.liferay.com) represents a complete Java EE application, using technologies such as Web, EJB, and JMS, especially the use of struts framework technology in its foreground interface. The xml-based portlet configuration file can be dynamically extended, using Web services to support the acquisition of some remote information, and using APAHCE Lucene to implement Full-text search capabilities.

The disadvantage of Liferay is that it lacks a simple and clear extensible architecture design, portlet design is more messy, it is difficult to carry out two times development

OFBiz

OFBiz (http://www.ofbiz.org/) is an influential Open-source software, OFBiz is a large software framework that tries to keep pace with the Java EE Framework technology, and its core is three engines: the physical engine, service services, and the workflow engine, The biggest advantage of OFBiz is its convenient entity engine, which can quickly develop hundreds of data tables.

The OFBiz service engine provides specific implementations such as workflows, soap, and so on, so that users can use the technology they need to use directly through the service engine, similar to a dynamically accessible API library.

OFBiz also has its own security authority control framework that can be bundled with each service.

OFBiz's disadvantage is that because of its attempt to build an all-encompassing large frame system, which inevitably leads to the complexity of its architectural organization, it is difficult to attempt to develop the overall two times, and OFBiz is mainly a web-structured system, which is deficient in transaction processing, security, and distributed computing. Of course ofbiz some of the best modules and components are worth learning and direct use.

Combining these kinds of portal software, one of their common flaws is the establishment of a user security authority control framework, once the use of any of these security frameworks, the entire framework of the system has been forcibly fixed, can not be flexible expansion and change, and they are currently common with the JAAS mechanism does not mix.

In practical application, the user Security authority control should be an independent, but with the specific application system related dynamic scalable system, by using the JAAS mechanism of Java EE can realize a distributed environment of single sign-on (SSO), access to flexible configuration dynamic system.

Architecture Design

Integrated with several existing portal design concepts, this project is fully structured within the Java EE Standard Framework, making full use of the technology framework resources of the whole Java EE, the project will be built into a distributed cluster environment, dynamic scalable flexible large-scale system.

Drawing on the idea of domain tree structure in the Apache slide, the portal can be considered a collection system under the control of a tree structure, as shown in Figure 7-3:

Fig. 7-3 The tree structure control of the portal system

In figure 7-3, whether static news content information, or online business dynamic interactive functions, they belong to a specific resource resource, through the tree structure and a node to achieve connectivity, so that resources can be inserted into the entire portal system, but also through the tree structure to facilitate the management of these resources.

Absorbing the idea of domain and namespace in the Apache slide, you can think that the whole application system is a domain, if the application system is a portal system, the web directory structure corresponding to the Web application layer is as follows.

Portal

|

|---web-inf

|----Admin

|----Forum

|----Taxation

|---Account

In the diagram above, the root directory "/" is a domain. In this root directory, there are a variety of resources, forum to represent the Forum function; Taxation represents an online tax-related service resource; account represents the resource for personal accounts, so that in the web layer, resources are positioned through relative path paths, such as/ Forum can be located in the domain of the Forum resources, in fact, the relative path also belongs to a URI (Uniform Resource Locator).

Because the Web container implements the access control of the role, the access rights of a path path can be set flexibly in Web.xml, so this actually solves the problem of the security permission control of the resource.

The architecture diagram for the entire system is as follows:

The tree structure in the portal system is similar to an organization chart of the system, which belongs to the high control part of the systems, and the access management of the tree structure is implemented in the service layer.

In order to cope with the possibility of a huge amount of traffic at any time, the formation of a distributed cluster environment via Java EE will have powerful processing capabilities, taking the JBoss server as an example:

Unified user Management and security authority mechanisms

By using the Jaas (Java authentication Authorization Service:java Authentication and authorization APIs) provided by the EE container, Jaas is a Java EE server to help the application system implement security features, When the developer of the application system implements the Loginmodule API, the Java-EE container executes the Loginmodule interface, and the relationship between the interface and the concrete implementation, the Java container will implement the specific Jaas function with the specific application system.

Access rights (ACLs) will use the security mechanism of the Java EE container, in the Web layer and the EJB layer have the corresponding standards to achieve role-based access to resources control, through a simple container ACL configuration, can facilitate the allocation of rights and control, at the same time, security configuration work and security implementation of the work can be completely separated, Prevent fraud.

The establishment of a unified LDAP based centralized user data system, which can achieve the entire system user single sign-on (SSO), that is to say: The entire system has only one access point, it is universal for all requests. Single sign-on can ensure that users can access resources, if there is an unauthorized request to access the protected resources, this request will automatically be directed to the appropriate verification points for login verification.

System Integration and communication solutions

Considering the complexity of the whole e-government system, the new and old technical standards are inconsistent, so there are many kinds of data integration program, according to the specific circumstances of different choices.

Integration with legacy systems EAI is achieved by building a middleware infrastructure and several adapters that allow different backend applications to be plugged into one type of public protocol to exchange data with each other.

JMS and JCA

The Java Messaging Service (JMS) and the Java 2 Connector Architecture (JCA), which are designed to integrate the EE application with the non-Java environment, have been set up to implement this adapter role in the EE environment.

JMS is an asynchronous message system that implements the delivery service between the message producer and the message consumer, and the message system provides many other advantages that are not available in other distributed object computing models. It encourages "loose coupling" between the message creator and the consumer, and there is a high degree of transaction processing between them. For the user, it does not care who generated the message, whether the creator is still on the network, and when the message was generated. This allows for the establishment of dynamic, reliable and flexible systems. The entire subsystem can be modified without affecting other parts of the system.

The Java 2 connector architecture defines a method for enabling Java EE applications to communicate in a secure, transactional manner, typically an enterprise information system (Enterprise Information System), or EIS. A solution that leverages the JCA API is more tightly coupled to the backend than a JMS based solution; More specifically, the JCA specification can combine the sending and handling of messages in the same message exchange or in the same transaction. The processing of the EIS is synchronous and can therefore be part of the transaction managed by the Java EE Application Server. As a result, business processes that are run across multiple back-end applications by a Java application can be transactional-the steps performed by these applications are either all committed or not submitted in one step.

Data exchange based on various protocols

BIE (Http://www.brunswickwdi.com/index.pl/bie) is designed to help organizations exchange data between different operating systems and implement EAI and business-to-business solutions, similar to Microsoft's BizTalk But there are two big advantages:

L Achieve data exchange with Java to truly cross-platform

L Open source code, suitable for two times open

You can use Bie to accept data documents from other applications or other businesses and convert them into XML for your application. Instead, you can get data from your application and provide it to other applications or businesses using BIE in different formats. In either case, the data starts out as a format, which is then converted to XML through BIE, and then you can output the data in a completely different format. Whether they are data sources or data recipients, their data formats need not be the same or even XML-formatted.

Bie is not only a data Exchange server, it also provides a powerful graphical business flow control tool. The business analyst paints a business flow in a similar flowchart tool to achieve the required functionality.

Become a standard Web service provider

Once the e-government system takes shape, the information contained in the whole system and the powerful function service will become the most powerful resources in the society, how to serve these resources better in the society, let the society all walks of life in their own way to fully tap the value of the data information will become the primary issue.

It is a development trend for the outside world to share or invoke its own resources directly through Web services technology, such as meteorological information is published by the Government Meteorological Department, but almost all news Web sites or portals require local meteorological information, so it can be provided through Web services.

A typical Web service (Web Services) architecture consists of three entities: Service providers, service brokers, and service demand providers. They provide three basic features: Run publishing, find, and bind. The service provider creates the Web service and registers the publishing Network service with the Service Broker; The Service Broker is responsible for maintaining the registration system of the published service; The service demand person searches for the service required by the registration of the Service Broker, and binds the service request to the service provider to use the specific service.

E-government system because of its rich and powerful resources and information, it is rightfully a service provider, these resources and information may be the most of the local community, it is possible to become the largest local Web service providers.

At present, Web services are in the practice and improvement, in which security, management or transaction issues still need to be further resolved, but in the planning of the entire e-government system must be included in the Web services.