first, what is WebService? In fact, the main goal of WebService is cross-platform interoperability. To achieve this goal, WebService is based entirely on platform-independent, software-vendor-specific standards, such as XML (Extensible Markup Language), XSD (XmlSchema), and is a new platform for creating interoperable, distributed applications.
second, the advantages of WebService
Advantage One: cross-firewall communication
For example, to add a new page to an application, you must first create a user interface (Web page), and then, after this page, include the middle-tier component of the corresponding business logic, and then create at least one ASP page to accept user input, call the middle-tier component, Format the result as HTML and finally return the results page back to the browser. If client code is no longer so dependent on HTML forms, the client's programming is much simpler.
if the middle-tier component is replaced with WebService, the middle-tier component can be called directly from the user interface, eliminating the step of building an ASP page. To invoke WebService, you can use SOAP clients such as Microsoftsoaptoolkit or. NET, or you can use your own SOAP client, and then connect it to your application. It not only shortens the development cycle, but also reduces the complexity of the code and improves the maintainability of the application. At the same time, the application no longer needs to jump to the corresponding results page each time the middle-tier component is called.
from experience, in an application with more interaction between a user interface and the middle tier, using the WebService structure can save 20% of the development time spent on user interface programming. In addition, such an intermediate layer composed of webservice can be reused in application integration or other situations. Finally, the application's logic and data are "exposed" through webservice, and can be reused by customers on other platforms.
Advantage Two: application integration
For example, there is an order sign-in program for logging in new orders from customers, including customer information, shipping address, quantity, price, and payment method, and an order fulfillment program for the management of the actual delivery of goods. The two programs come from different software vendors. After a new order comes in, the order login procedure needs to notify the order execution program to send the goods. By adding a layer of webservice to the order execution program, the Order execution program can "expose" the "AddOrder" function. Thus, the order login program can call this function to send the goods whenever a new order arrives.
Advantage Three: business-to-business integration
integration of applications with WebService enables more automated business processing within the company. But what happens when the deal crosses the boundaries of the supplier and the customer and breaks through the company? Cross-company business transaction integration is often referred to as a to-do integration.
WebService is the key to the success of business-to-business integration. Through webservice, companies can "expose" critical business applications to designated suppliers and customers. For example, the electronic order system and the electronic invoice system "exposed", the customer can send orders electronically, the supplier can electronically send raw material purchase invoices. Of course, this is not a new concept, EDI (electronic document exchange) has been so long. However, the implementation of WebService is much simpler than EDI, and webservice runs on the internet and can be easily implemented anywhere in the world, with relatively low operating costs. However, WebService is not a complete solution for document exchange or business-to-business integration, as EDI does. WebService is just a key part of business-to-business integration, and many other parts are needed to achieve integration.
the biggest benefit of using WebService for business-to-business integration is the ease of interoperability. As long as the business logic is "exposed" and becomes webservice, it is possible for any designated partner to invoke these business logic, regardless of the platform on which their system runs, and what language to use. This greatly reduces the time and cost of spending on business-to-business integration, and enables many small and medium-sized enterprises that cannot afford EDI to achieve business-to-business integration.
Advantage Four: Software and data Reuse
software reuse is a big topic, the form of reuse is many, the degree of reuse is very small. The most basic form is the reuse of the source code module or class one, and the other form is the reuse of the component in binary form.
Currently, reusable software components such as tabular controls or user interface controls occupy a large share of the market. But there is a big limit to the reuse of such software, which is that reuse is limited to code and data cannot be reused. The reason is that publishing components and even source code is easier, but publishing data is not so easy, unless it's static data that doesn't change very often.
WebService can reuse the data behind the code while allowing reuse of the code. With WebService, you don't have to buy, install software components from a third party, and then call those components from the application, just call the remote webservice directly, as you did before. For example, to confirm the address entered by the user in the application, simply send the address directly to the corresponding WebService, this webservice will help you to check the street address, city, province and zip code and other information, confirm whether the address in the corresponding ZIP code area. WebService providers can charge for this service by time or by number of uses. It is impossible for such a service to be implemented through component reuse, in which case you must download and install a database that contains information such as street addresses, cities, provinces, and postal codes, and the database cannot be updated in real time.
Another scenario for software reuse is to integrate the functionality of several applications. For example, to create a portal application on a local area network, users can query FedEx parcels, view stock quotes, manage their own schedules, and buy movie tickets online. Now there are many application vendors on the Web that have implemented these features in their applications. Once they are "exposed" through webservice, they can easily integrate all of these features into your portal, providing users with a unified, user-friendly interface.
In the future, many applications will use WebService to extend the current component-based application architecture to a hybrid structure of component/webservice, using the functionality provided by third-party webservice in applications, or by putting their own applications The order function is provided to others through WebService. In both cases, the data behind the code and the code can be reused.
As can be seen from the above discussion, WebService is most useful when interoperating through the Web or remotely. However, there are some situations where WebService does not bring any benefits at all.
disadvantage One: stand-alone Applications
today, businesses and individuals are also using many desktop applications. Some of them only need to communicate with other programs on this computer. In this case, it is best not to use the WebService, just use the local API. COM is well suited to working in this situation because it is both small and fast. This is also true for server software running on the same server. It is best to use COM or other local APIs directly to make calls between applications. Of course webservice can also be used on these occasions, but that not only consumes too much, but does not bring any benefits.
disadvantage two: homogeneous application of LAN
in many applications, all programs are developed with VB or VC, all in the Windows platform using COM, all running on the same LAN. For example, there are two server applications that need to communicate with each other, or a WIN32 or WinForm client program that connects to another server on the LAN. In these programs, using DCOM is much more effective than soap/http. Similar to this, if one. NET program to connect to another. NET program on the LAN, you should use the. netremoting. Interestingly, in. Netremoting, you can also specify to use Soap/http to make webservice calls. However, it is best to make RPC calls directly over TCP, which is much more effective. transferred from: http://blog.csdn.net/chaobeyond/article/details/2247117
Summary of advantages and disadvantages of WebService (RPM)
