Simple Object Access Protocol (SOAP)

Simple Object Access Protocol (SOAP)

SOAP Summary Simple Object Access Protocol (SOAP) improves the interactivity of the Internet by planning a website based on XML, and platform-independent methods. The Introduction INTERNET is fundamentally changed, thereby fundamentally changing the way business implementation. Transition to e-commerce results in a huge wavy reaction in all computer systems. As the company integrates their customer management, order implementation systems, and their online sales systems, the role of websites will be getting smaller and smaller. The next step will extend between business partners, such as suppliers and publishers. In addition to integrated various business systems through the Internet, there are other phenomena that drive network development, service. For example, users need more, deeper, more personalized, and more active services, serving their work or personal life, which is for their interests, while saving their time, money and difficulties. As a result, the network is developing from a website that provides simple service from some web pages to dynamic web services, which can interact some complex steps to serve users. These tasks may require a Web service to call additional web services, adjust the step execution command like a traditional software program. The problem facing today is the integration of other services and the connection with other equipment is still difficult, because it is still lacking some tools and general agreements that mutual contact. The network needs a general method that combines all services. Multiple services can work seamlessly, and you must be able to easily coordinate the various service steps on the Internet, which is easy to create new and customized services. Developers must be able to integrate, not just providing services. They need to form a solution from any software components, applications, business processes, devices, or other intellectual property rights. This requires a common goal that allows developers in the Internet to work together - this is a new application model that connects the distributed and reliable way to distributed service and components for distributed components to provide core programming services. Previously, create such complex applications for the application's communication is the use of an object model, such as Microsoft's DCOM or Object Management Group's Internet Inter-ORB Protocol (IIOP) or Common Object Request Broker Architecture (CORBA). But these technologies have some shortcomings when creating a web service. Specifically, DCOM and IIOP / CORBA are complex environments, meaning that applications that use them are usually complex and uniform. In other words, use them to create a distributed application, usually requires the same distribution object model on both ends of the connection. But the Internet does not guarantee the other end of your connection to run specific customer and service software, such as HTTP. And to make everyone running IIOP or COM is unrealistic, it is not possible to technology. A solution to solve this problem is to use existing Internet standards: http and xml. More than any other application protocol, the hypertext transfer protocol is connected to the entire world. Millions of websites and browsers have proven this. If you don't have an e-mail client software, you can use E-mail through a website; if you want to connect to the Internet with other than HTTP, you will find that most other application protocols are most It can be tolerated, and it is usually blocked outside by the firewall. The problem with HTTP alone is that it is mainly a mechanism to transfer files to the client. To create a better web service, you need to extend HTTP. SOAP is better to meet this request: it joins a set of HTTP titles and a rich XML that enables communication with complex applications and applications on the Internet. What does SOAP do and not do what SOAP communication protocol uses HTTP to send information about XML format. The regular target of the SOAP specification includes two levels: provide a standard object call protocol for an Internet standard, transmitted through HTTP, and the data is encoded into XML format.

Create an extensible protocol and payload format to upgrade over time. The author of this specification clearly creates a more spicy hand portion of the object model and is excluded from the created part. They pointed out that they don't want to "define all aspects of a distributed object system." This means that there is no distributed garbage accumulation, type safety or version, no two-way HTTP communication, no messaging or pipe process, no reference object, and no activation object. SOAP means simple - can be done on any operating system in any operating system by a developer in a few days. These although not the goals of the SOAP itself, they can be implemented in SOAP environment - not just SOAP. They need you create yourself by any available tools. SOAP Definition SOAP defines a mechanism for transferring commands and parameters in an HTTP client and server. SOAP does not care what operating system, programming language or object model used in server-side or client: In addition to using HTTP transmission, it is independent of other. SOAP is simple. The client sends a request to the server, call the corresponding object, and then the server returns the result. These messages are XML formats and packaged into messages that meet HTTP protocols. SOAP works through the existing internet. You don't need to do anything, it meets any routers, firewalls, or proxy servers. The SOAP customer request is packaged in an HTTP POST (or M-POST) package. The following example taken from the Internet-draft specification: POST / StockQuote HTTP / 1.1 Host: www.stockquoteserver.com Content-Type: text / xml Content-Length: nnnn SOAPMethodName: Some-Namespace-URI # GetLastTradePrice DIS / SYMBOL> The first four lines are standard HTTP: POST is the verb of HTTP, all HTTP messages require hosts. The Content-Type and Content-Length section are all required for all HTTP messages containing PayLoad. Content-type "text / xml" indicates that PAYLOAD is an XML message sent to the server (or a message that sends a firewall with scan application header) XML code is easy to understand, such as: Envelope and Body section specifying ordinary Payload packaging mechanism; section includes a part called , which contains a symbol of stock trading. The purpose of this request is to be very obvious: get the last transaction price of a particular stock - DISNEY (DIS). The program that sends this message only needs to know how to format a SOAP request: constitutes a request to request the HTTP header format and XML format required. In this example, the program knows that it is necessary to form a request for an stock price. The HTTP server receiving this message knows this is a SOAP request by this http header SOAPMETHODNAME; then the server sends or process the corresponding part of the message. SOAP Description SOAP defines two types of messages, requests, and responses, allowing clients to be able to deliver a remote request, allowing the server to respond to these requests.

The above is an example of a request; the response to this request is listed below: http / 1.1 200 ok content-type: text / xml content-length: nnnn 34.5 < / SOAP: Envelope> The first three lines remain standard HTTP: The first line indicates that this is a response to the previous POST request, the second line and third line points out the content type and length. The XML head packages a soap payload. The XML section contains a response to a transaction price request; its sub-portion indicates the value returned to this request. The key part of SOAP description is the HTTP verb POST and M-POST, an additional HTTP header, and the namespace required for XML, thereby avoiding errors that may be brought to replication in different environments. This description also demonstrates the method called by SOAP and the type of data processed. If you are still confused, M-POST verbs are designed from HTTP Extension Framework Internet. A new HTTP verb defines how a new HTTP verb is created by adding characters "M-" on the basis of the verb. Receiving a request containing these verbs, the server must respond according to this verb. If a POST operation fails (for example, the firewall is blocked), the SOAP description will suggest that you will try again with M-POST. This allows SOAP to be an error that can be replaced, but does not need a firewall to complete any extended features. SOAP and Object Model SOAP does not require any object model, nor does it require other communication entities to use object models. On the basis of avoiding the object model, SOAP leaves most object functions (such as initialization code and garbage accumulation) to the underlying of the client and server-side work, while other functions (such as signal editing) can be left to SOAP synthesis The application and the underlying structure are completed. SOAP can be done in any language, as long as the client sends the correct SOAP request (that is, pass a suitable parameter to an actual remote server). SOAP has no object model, the application can bundle in any object model. Early SOAP features have Java, Perl, and Windows versions earlier. When each function becomes the parameters and responses that the SOAP entity can understand (for example, the data is saved in an XML element, and is encapsulated in the HTTP message), it can interact with other SOAP functions. There are two different ways to use SOAP programming using SOAP programming, which is determined whether SOAP already exists in your underlying structure (for example, completing or put it in your operating system) or you have created a SOAP underlying structure . Creating the underlying structure for SOAP Use SOAP without having to create a distributed object; after all, the SOAP itself is designed to send messages from an object from an object to another, not on any message. In theory, this means that a SOAP interface can be created between the system by judging the data type (from client request) and data type required to send (respond to the request).