KR20110056058A - Apparatus and method for mediating web service - Google Patents

Abstract

PURPOSE: An apparatus and method for web service mediation is provided to eliminate the necessity of mediating middle ware such as an ESB(Enterprise Service Bus) by determining a conversion rule for a target service. CONSTITUTION: A message receiving unit(200) receives a web service request message from a web server. A converting rule storage unit(240) stores the converting rule information. According to the stored converting rule information of the converting rule storage unit, a request message converting unit(210) changes the received request message into a different web service call sentence. The request message converting unit performs the web service call sentence.

Description

[0001] Apparatus and method for mediating web service [

The present invention relates to a web service, and more particularly, to an intermediate apparatus and method for enabling a web service when a communication method used by a service provider for providing a web service is different from a communication method used by a service user for receiving a web service .

[2009-F-048-01, Project: Development of Common Platform Technology for Network-based Customer-Oriented Convergence Service] The present invention is derived from the research conducted as part of the Ministry of Knowledge Economy.

A Web service is a distributed computing technology that makes it possible for a service consumer to easily access and use complex services provided by a service provider. The technologies that make up the Web service include Simple Object Access Protocol (SOAP), Web Service Description Language (WSDL), and Universal Description, Discovery and Integration (UDDI). These are standardized technologies.

WSDL (Web Service Description Language) is an XML (extensible markup language) format describing a service interface. The service provider describes the interface of the service to be provided using WSDL, and the service user can access the service using the service interface described in WSDL.

UDDI (Universal Description, Discovery and Integration) publishes service related information of a service provider and enables a service user to search for desired service. SOAP is a protocol for a service user to invoke a service provided by a service provider.

Recently, service-oriented architecture (SOA) has been spotlighted, and web service technology as its underlying technology has attracted attention as a representative technology of distributed computing technology.

On the other hand, with the proposal of Web 2.0, a REST (re-emphasent state transfer) style web service that does not use SOAP (Simple Object Access Protocol) is getting attention. REST-style Web services are used to simplify the Web 2.0 Open API. REST-style Web services also use Hypertext Transfer Protocol (HTTP) and Extensible Markup Language (XML) to exchange data. REST-style Web services have advantages in that they are easier to use than SOAP-based Web services. Because of the advantages of such REST-style Web services, there is a need to provide existing SOAP-based Web services to REST-style Web service users.

To do this, there is a way to re-develop a REST-style Web service that has the same functionality as a SOAP-based Web service. However, this method has a problem that it is inefficient because the development cost is duplicated.

Meanwhile, the ESB (Enterprise Service Bus) integrates various types of applications existing in the enterprise into a SOAP-based web service form and provides the service user with the intermediation function for converting the service request of the service user into the existing application communication form and routing . However, ESB is expensive software and is typically used as a means to integrate and integrate legacy applications within the enterprise. Therefore, it is expensive to use SOAP-based Web service for intermediation purpose to provide REST-style Web service users with cost and size.

The present invention has been made in view of the above background, and it is an object of the present invention to provide a method and apparatus for intermediating a SOAP-based web service to a REST-based web service user without a large structural change in the web service network.

The present invention is directed to a method and apparatus for receiving a web service request message from a web server, including a message receiving unit for receiving a web service request message from the web server, a conversion rule storing unit for storing conversion rule information for converting the received web service request message into a different type of web service call, And a request message converting unit converting the received request message into a different type of web service call statement and executing the converted request message according to the conversion rule information stored in the web service brokerage unit.

At this time, the request message conversion unit converts a service request message based on a REST (REpresentational State Transfer) into a web service call statement capable of calling a service based on SOAP (Simple Object Access Protocol).

According to another aspect of the present invention, there is provided a web service providing method comprising: receiving a web service request message from a web server; converting the received web service request message into a different type of web service invocation statement according to pre- And transmitting the web service request message to the web server by executing the web service request message.

According to the present invention, there is no need to re-develop a REST-style Web service having the same function as a SOAP-based Web service, or to program a service-specific mediation module at a high cost. In addition, it is not necessary to introduce intermediary middleware such as ESB by defining conversion rules for target service, and it is easy to provide SOAP-based web service to REST-based style web service user.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and further aspects of the present invention will become more apparent from the following description of the preferred embodiments with reference to the attached drawings. Hereinafter, the present invention will be described in detail in order that those skilled in the art can easily understand and reproduce the present invention through these embodiments.

1 is a configuration diagram of a web service providing system according to an embodiment.

As shown, the web service provision system according to an embodiment includes a web server 10, a web service intermediary apparatus 20, a SOAP engine 30, and a SOAP-based web service 40.

The web server 10 receives a service request message according to HTTP from a service user through a web browser and responds to the received service request message using the contents of a web page such as an HTML document. At this time, the service request message received by the web server 10 may be a REST-based service request message or a SOAP service request message. The web server 10 can grasp whether it is a REST-based service request message or a SOAP service request message by grasping the data included in the received message. If the REST service request message is received, the web server 10 transmits the message to the web service intermediary apparatus 20, and if the SOAP service request message is received, the web server 10 transmits the message to the SOAP engine 30.

Also, the web server 10 transmits the SOAP-based web service invocation statement received from the web service intermediation apparatus 20 to be described later to the SOAP engine 30 as when the SOAP service request message is received from the service user.

The web service intermediary apparatus 20 analyzes the received service request message and extracts the interface of the REST based web service. Then, based on the pre-stored conversion rules, the conversion rule corresponding to the extracted web service interface is searched. At this time, the interface of the web service includes HTTP method information and URL resource information. Then, a SOAP-based web service invocation statement is generated and executed based on the recognized transformation rule, and the SOAP-based service request message is transmitted to the web server 10. The SOAP engine 30 calls the SOAP-based web service 40 accordingly.

Then, the resultant value is received from the called SOAP-based web service 40, converted into an HTTP response message according to the conversion rule, and transmitted to the service user. The SOAP engine 30 analyzes the received SOAP service request message and activates the corresponding SOAP based web service. The SOAP-based web service 40 includes a service logic program, and when activated by the SOAP engine 30, a service logic program is executed.

2 is a configuration diagram of a web service mediator according to an embodiment.

The web service intermediary apparatus according to one embodiment includes a message receiving unit 200, a request message converting unit 210, a conversion process managing unit 220, a conversion rule providing unit 230, and a conversion rule storing unit 240 .

The message receiving unit 200 receives the HTTP request message from the web server 10. The received HTTP request message is a REST based service request message.

The request message conversion unit 210 analyzes the received HTTP request message and extracts the interface of the REST-based web service. Then, it finds a changed rule corresponding to the extracted service interface, generates a SOAP-based web service invocation statement based on the generated rule, and invokes the SOAP service. Then, the resultant value received from the SOAP service is converted into an HTTP response message according to the conversion rule, and then transmitted to the service user. At this time, the request message conversion unit 210 generates and executes a SOAP-based web service invocation statement, transfers the SOAP-based service request message to the web server, and receives the resultant value from the web server.

The conversion process management unit 220 generates and manages a conversion process for performing a conversion function of a request message in the request message conversion unit 210. When the request message conversion unit 210 fails to generate an HTTP response message due to an exceptional situation during the conversion process, the conversion process management unit 220 determines the type of the error and transmits an HTTP response code . Then, the conversion rule corresponding to the HTTP response status code is recognized, and an HTTP response message is generated according to the conversion rule and transmitted to the service user.

The conversion rule storage unit 240 is implemented as a data storage device such as a memory and stores conversion rules.

The conversion rule providing unit 230 detects and provides a conversion rule suitable for the conversion process corresponding to the conversion process stored in the conversion rule storage unit 240 according to a request from the request message conversion unit 210. [

3 to 5 are exemplary views of a conversion rule table according to an embodiment.

The conversion rule table includes an error conversion rule storage table that is commonly applied to all services and a service-specific conversion rule storage table that is differently applied to each service.

The error conversion rule storage table stores a conversion rule for generating a response message indicating the type and cause of an error when an error occurs in the called web service. As shown in FIG. 3, the error conversion rule storage table includes an HTTP response status code field and a response message template field. The HTTP response status code field indicates the error code and is used as an identifier of the table. The response message template consists of a response message header and a body. The message header includes information such as content-type information and content-length information. The message body is described according to one of the data representation methods, such as XML and RSS (Really Simple Syndication), and contains information on the type and cause of the error.

As shown in FIG. 4, the service-specific conversion rule storage table includes an HTTP method field, a URL resource field, an input parameter conversion rule field, and a result value conversion rule field. The HTTP method field and the URL resource field are used to identify conversion rules. The conversion rule storage table includes an input parameter conversion rule field for converting a REST-based request message into a SOAP-based service call statement, a result parameter conversion rule field for converting a result value received from the SOAP service into a REST-based message format, And a rule field.

As shown in FIG. 5, the input parameter conversion rule includes a token index field of a URL query string, a data type information field to be converted, and an input parameter index information field of a target web service. In other words, the input parameter rule defines what data type should be mapped to which input parameter of the target web service the token number of the URL query string is to be mapped to.

The result conversion rule provides a default template for the header and body of the HTTP response message. The message header includes information such as content-type information and content-length information. The message body part is described by one of the data representation methods such as XML, JavaScript Object Notation (JSON) and RSS (Really Simple Syndication), and the data representation is represented by the tag name and value. Here, the value is the result value received from the called service, for example SOAP-based result. The result conversion rule describes that, when the result value received from the called service has a single value, the result value is directly mapped to a value of another Web service, that is, a REST based response message . On the other hand, when the result value is a composite value such as a structure, it is described to be mapped to the value of the REST-based response message for each of the field information and value information of the structure.

6 is a flowchart of a web service mediation method according to one embodiment.

First, the web service intermediary apparatus 20 according to an embodiment receives a service request message. The received request message is analyzed to determine HTTP method information or URL resource information (610). Then, the input parameter conversion rule is determined according to the analysis result (620). Then, the SOAP-based web service invocation statement is generated (630) by applying the identified input parameter conversion rule to the received HTTP request message.

Then, the SOAP-based web service is called according to the generated call statement (640).

Thereafter, if there is an error in the result value received from the SOAP-based web service (650), the kind of error is grasped (652). Then, an HTTP response status code indicating the occurrence of the error is generated (654). Thereafter, a conversion rule corresponding to the HTTP response status code is recognized based on the error conversion rule table (656), and an HTTP response message is generated according to the conversion rule (658).

If no error has occurred, the result value is received from the activated SOAP-based service and an HTTP response status code indicating successful service execution is generated. A response message is generated by generating a header and a body of the HTTP response message by applying the HTTP response status code to the result conversion rule field of the translation rule table. Then, the generated response message is transmitted to the service user via the web server (670).

FIG. 7 is a detailed flowchart of a transformation rule determination method according to an embodiment, and FIG. 8 is a detailed flowchart of a web service call statement generation method according to an embodiment.

First, an HTTP method is extracted from the received HTTP message (622). Then, a URL resource is extracted (624). The HTTP method field and the URL resource field are used to identify conversion rules. Then, the input parameter conversion rule and the result value conversion rule corresponding to the HTTP method and the URL resource extracted from the service-specific conversion rule storage table are grasped (626).

Then, a URL query string is extracted from the received HTTP request message (632), and the extracted query string is cut in token units (634). The separated query string token is applied to the identified input parameter conversion rule to generate a SOAP-based web service invocation statement (636).

For example, in an input parameter conversion rule, the URL query string token index is sequence information. The input parameter conversion rules define what data type should be mapped to which input parameter of the target web service the token number of the URL query string is to be mapped to. That is, the REST-based request message is divided into token-unit URL query strings according to the input parameter conversion rule and matched to the SOAP-based request message input parameter, thereby generating the same SOAP request service call syntax as the SOAP-based request message format .

On the other hand, the above-described Web service mediation method can be created by a computer program. Also, the program may be stored in a computer-readable medium, readable and executed by a computer, and executed. The storage medium includes a magnetic recording medium, an optical recording medium, and the like.

The present invention has been described above with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

1 is a configuration diagram of a web service providing system according to an embodiment,

FIG. 2 is a configuration diagram of a web service intermediary apparatus according to an exemplary embodiment.

Figs. 3 to 5 are exemplary views of a conversion rule table according to an embodiment,

6 is a flowchart of a web service mediation method according to an embodiment,

7 is a detailed flowchart of a conversion rule grasping method according to an embodiment,

8 is a detailed flowchart of a method for generating a web service call statement according to an embodiment of the present invention.

Claims (17)

A message receiving unit for receiving a web service request message from a web server; A conversion rule storage unit for storing conversion rule information for converting the received web service request message into a different type of web service request message; And And a request message conversion unit converting the received request message into a different type of web service call statement according to conversion rule information stored in the conversion rule storage unit and executing the converted request message. The method according to claim 1, Wherein the request message conversion unit converts a service request message based on a REST (REpresentational State Transfer) to a web service invocation statement capable of invoking a service based on a SOAP (Simple Object Access Protocol), and executes the web service invocation statement. The method according to claim 1, Wherein the request message conversion unit converts a web service result value received from the web server into a different type of web service response message according to the conversion rule information stored in the conversion rule storage unit. 3. The method of claim 2, The transformation rule information includes a data transformation rule table for transformation into a different type of web service request message and an error message transformation rule table for generating an error occurrence message when an error occurs in the received web service result value Characterized by a web service intermediary device. 5. The method of claim 4, Wherein the data conversion rule table includes a message identification information field, an input parameter conversion rule field, and a result value conversion rule field. 6. The method of claim 5, Wherein the input parameter conversion rule field includes token index information, conversion data type information, and parameter index information. The method according to claim 6, Wherein the request message conversion unit separates at least a part of the received service request message in units of tokens and identifies parameter information and data types mapped in the token unit based on the input parameter conversion rule field, To the Web service request message. 6. The method of claim 5, Wherein the message identification information field includes an HTTP method field and a URL resource field. 6. The method of claim 5, Wherein the result conversion rule field includes basic template information for a header and a body of a response message. 5. The method of claim 4, Wherein the error message conversion rule table includes an error identification information field, a header of the error message, and basic template information for the body. Receiving a web service request message from a web server; Converting the received web service request message into a different type of web service call according to pre-stored conversion rule information; And And executing the transformed web service invocation statement. 12. The method of claim 11, Wherein the converting step converts a service request message based on a REST (REpresentational State Transfer) to a web service invocation statement capable of invoking a service based on a SOAP (Simple Object Access Protocol). 12. The method of claim 11, Receiving a web service result value from a web server; Converting the received result value into a different type of web service response message; And And transferring the converted response message to a web server. 14. The method of claim 13, Wherein the converting step converts the received response value into a response message indicating that an error occurs when an error occurs in the received result value. 12. The method of claim 11, Extracting an HTTP method from the received web service request message; Extracting URL resource information from the received web service request message; Determining an application rule of pre-stored conversion rule information based on the extracted HTTP method and URL resource information; And And converting the received web service request message into a different type of web service invocation statement according to the identified application rule. 16. The method of claim 15, wherein transforming the received web service request message into a different type of web service invocation statement according to the identified application rule comprises: Separating at least a portion of the received web service request message in token units; And And transforming the data into data mapped in the separated token unit according to the identified application rule. 17. The method of claim 16, Extracting a URL query string from the received web service request message; And And separating the extracted URL query string in token units.

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