JP6265473B2 - Web service system, Web service message mediation method, and proxy server - Google Patents

Description

  The present invention relates to a web service system, a web service message mediation method, and a proxy server, and more particularly, to a web service system, a web service message mediation method, and a proxy server that are excellent in extensibility of API specifications.

  The Web service system includes a plurality of application servers that execute various functions, and exchanges messages using a protocol such as REST or SOAP between the application servers for cooperation.

  FIG. 6 shows the basic configuration of the Web service system. This Web service system includes four application servers illustrated as systems A to D. The systems A to D perform different functions. Here, the system A functions as a backbone system that exchanges various messages with the systems B to D and cooperates with the entire Web service system. Systems B to D perform different functions. Further, the systems B to D can acquire various types of information processed by other systems by exchanging messages with the system A or with other systems via the system A as necessary.

  Each of the systems A to D includes a program and an API (application programming interface). The API specifications of each system A to D are standardized, so that the systems A to D can understand each other's messages. The API specifications of each system A to D may be extended to extend the functions of the Web service system. However, the API specifications of all the systems A to D that make up the Web service system are extended. This is effective when A to D can understand each other's messages.

  In Patent Document 1, regarding the network management device, SNMP management information and CMIP management are managed in order to match the difference in information system between SNMP management information and CMIP management information and to create a management application with high portability and expandability. Provide a consistency information database that stores information for matching the difference in information system with the information, and convert the information system between NMP management information and CMIP management information by referring to the information stored in this consistency information database Is described.

Japanese Patent Laid-Open No. 7-250065

  As described above, in the past, the API specifications for extending the functions of a Web service system are not only the API specifications of a specific system, but the API specifications of all systems that make up the Web service system. It will be effective.

  For example, as shown in FIG. 6, when only the API specification of system D is expanded by increasing the number of commands, parameters, and arguments of the Web service message, system D sends a message based on the API specification. However, the system A cannot understand it, and even if the system A understands the message, the system B to C cannot understand it. In order to eliminate this inconsistency, all API specifications of the systems A to D need to be extended.

  In such a case, the increase in the man-hours for extending the API specifications becomes a hindrance to the expansion of Web service system functions. For this reason, even if the API specification of a specific system constituting the Web service system is extended, it is desired that the influence on the entire Web service system is small, and that the extension of the API specification becomes as effective as possible.

  Cited Document 1 discloses a technique for matching interface differences using a matching information database. However, with such a technique, it is easy to match the interface differences between the one-to-one systems, but it is difficult to match the interface differences between the many-to-many systems. In Web service systems, API specifications are often expanded in many-to-many systems, so the technique in Cited Reference 1 is extensible in terms of dealing with various interfaces in Web service systems. It's not good.

  In addition, it is possible to use only the system with the API specification expanded among the systems that make up the Web service system, and ignore the expansion in the unexpanded system. Although this method can reduce the impact when the API specification of a specific system is extended, the service by extending the API specification is limited to the systems where the API specification has been extended, and other systems have their services. Can not receive at all. In the end, the extension of the system API specifications will directly affect the Web service system.

  Another possible method is to link the systems that make up the Web service system via an API that is an intermediate language. According to this method, when the API specification of a specific system is extended, it can be dealt with by simply changing the conversion between the message of the system with the extended API specification and the intermediate language. However, it is necessary to create an intermediate language in advance of the API specification expansion, which is difficult to implement.

  An object of the present invention is to provide a Web service system, a Web service message mediating method, and a proxy server that solve the above-described problems and have excellent expandability of API specifications.

In order to solve the above problems, a web service system according to the present invention includes a plurality of application servers that execute various functions, and a proxy server that mediates a web service message exchanged between the plurality of application servers. Each application server has a program and API for executing its own function, and when the proxy server receives a Web service message from the application server, if it is a request command, it changes its contents without transferred to the request command receiver application areas Activation server, when receiving a normal response message thereto, forwards the request command source application areas Activation server without changing its contents, you receive an error message to the request command when is the request co According to the policy that is set in advance according to the change of the WSDL definition for command, either forward the request command, which is a partial modification of the specifications in the request command receiver Application areas Activation server, the request command received, possible to respond to it or forwarded to the application areas Activation server with sex, it is characterized by having a selective ability to run.

The web service message mediation method of the present invention is a web service message mediation method in a web service system composed of a plurality of application servers, wherein the first step of receiving a web service message and the first step a fourth step that sends Web service message according to the determination result of the second step of generating a WSDL definition in the received Web service message, a third step of performing processing determination in the third step by has the third step, when receiving the Web service message from the application server, if it is a request command is transferred to the request command receiver application areas Activation server without changing its contents, contrast If a normal response message is received, change its contents. Without transferred to the request command source Application areas Activation server, when receiving an error message to the request command, according to the policy that is set in advance according to the change of the WSDL definition for the request command, partially modified specifications a request command requesting command receiver application areas Activation or forwarded to the server, the request command received, whether to forward the app Ke Activation server that might respond to it, it is characterized by performing selective .

The proxy server of the present invention is a proxy server for a web service system composed of a plurality of application servers. When a web service message is received from an application server, if it is a request command, the content is displayed. forwards a request command receiver application areas Activation server without changing, when receiving a normal response message thereto, forwards the request command source application areas Activation server without changing the content, the error to the request command when receiving the message, according to the policy that is set in advance according to the change of the WSDL definition for the request command, or transfers the request command, which is a partial modification of the specifications in the request command receiver application areas Activation server was received Respond to the request command Is the first feature in that it has a function of Application areas Activation or forwarded to the server, to selectively execute that might.

Further, the proxy server of the present invention includes a receiving unit that receives a Web service message, a WSDL generating unit that generates a WSDL definition for a request command out of the Web service message received by the receiving unit, a processing determination unit, The WSDL definition stored in advance for each request command transmission source application server is updated by the transmission unit that transmits the Web service message according to the determination result by the processing determination unit, and the WSDL definition generated by the WSDL generation unit. Stores a WSDL database to be stored, a state management database that accumulates determination results in the processing determination unit along with transaction state transitions, a Web service message received by the reception unit, and a policy of an operation to be performed on the reception A policy database, and the processing determination unit includes the WSDL database. The difference between the WSDL definition before update stored in advance for each request command transmission source application server and the WSDL definition generated by the WSDL generation unit is obtained corresponding to the request command transmission source application server, and the difference is added. The WSDL definition is updated by storing it in the WSDL database for each request command transmission source application server as the WSDL definition, the processing result is accumulated in the state management database together with the state transition of the transaction, and the Web service message is received. when, if it is a request command, it is transferred to the request command receiver application areas Activation server without changing its contents, when receiving a normal response message thereto, the request command transmission without changing its contents transfer to the original application Quai Activation server It was, when receiving an error message to the request command, WSDL definition of according to the policy that is set in advance according to the change request command receiver Application areas Activation server request command, which is a partial modification of the specifications for the request command Luke is transferred to the request command received, whether to transfer the app Ke Activation server that might respond to it, and the second feature to run selectively.

Further, the proxy server of the present invention, the policy is, the parameters of the request command, if the difference is one, is transferred a request command that deletes the parameter request command receiver Application areas Activation server, the difference is 2 one of the cases, the difference is set so as to transfer the request command to the two following applications Ke Activation server, the request command itself, if the request command itself is unsupported, the request command, it can support app Ke The third feature is that it is set to be transferred to an application server.

  Furthermore, the proxy server according to the fourth aspect of the present invention is configured so that the policy further sets transfer of a request command or a request command in which a specification is partially changed in accordance with a difference in the number of arguments of the request command. It is a feature.

According to the present invention, even when an error message is returned from the request command transmission destination application server, a request command whose request is partially changed is received according to a policy set in advance according to a change in the WSDL definition for the request command. earlier application areas Activation or forwarded to the server, the request command received, or transferred to application areas Activation server that might respond to it, because selectively executes, scalable of API specification Web A service system can be realized.

  In addition, since the API specification in a specific application server can be handled by the policy stored in the policy database, an increase in man-hours for dealing with the API specification expansion can be suppressed. In addition, the extension of the API specification can be prevented from affecting the entire Web service system as much as possible, and the extension of the API specification can be used as effectively as possible.

It is a block diagram which shows one Embodiment of the web service system which concerns on this invention. It is a figure which shows the specific example of a REST message. It is a figure which shows the specific example of WSDL definition. It is a figure which shows the specific example of a namespace definition. It is a flowchart which shows an example of the process in WSP of FIG. It is a block diagram which shows the basic composition of a Web service system.

  The present invention will be described below with reference to the drawings. In the following description, it is assumed that a message (Web service message) exchanged between systems constituting the Web service system is a REST (Representational State Transfer) message.

  FIG. 1 is a block diagram showing an embodiment of a Web service system according to the present invention. The Web service system of this embodiment is different from FIG. 6 in that a proxy server (WSP: Web Services Proxy) 10 is provided.

  Here, the system A functions as a backbone system that exchanges various REST messages with the systems B to D via the WSP 10 to link the entire Web service system. Systems B to D perform different functions. In addition, the systems B to D receive various types of information processed by the functions of other systems by exchanging various REST messages with the system A via the WSP10 or with other systems via the WSP10 and the system A as necessary. You can get it.

  WSP10 mediates REST messages exchanged between systems A to D, and is provided to enable systems A to D to cooperate as much as possible even when the API specifications of a specific system are expanded. A REST API reception unit 11, a WSDL (Web Services Description Language) generation unit 12, a processing determination unit 13, a REST API transmission unit 14, a WSDL database (DB) 15, a state management database 16, and a policy database 17. The WSDL generation unit 12 and the process determination unit 13 can be configured with a CPU and software. Further, the WSDL database 15, the state management database 16, and the policy database 17 may be provided outside.

  The REST API receiving unit 11 receives various REST messages sent from the systems A to D.

  The WSDL generation unit 12 generates a WSDL definition from the REST message received by the REST API reception unit 11, particularly the REST message of the request command. If a namespace definition is required, it is also generated. The WSDL definition is the WSDL of the Web message specification, here the WSDL of the REST message specification, and the namespace definition is a WSDL that further refines the REST message specification. WSDL definitions in REST messages can be generated using the framework of WSDL 2.0 (or later). For generating the WSDL definition and the namespace definition, for example, refer to (http://www.ibm.com/developerworks/webservices/library/ws-restwsdl/#describerestservice).

  FIG. 2 shows a specific example of the REST message. This example shows an example of a request command that retrieves a list of content titled 'gone with the wind' and the response message that is returned. FIG. 3 shows a specific example of the WSDL definition, and FIG. 4 shows a specific example of the name space definition.

  The processing determination unit 13 is configured in advance using the framework of WSDL 2.0 (or later), and the WSDL definition (including namespace definition) stored in advance in the WSDL database 15 and the WSDL generated by the WSDL generation unit 12 A difference from the definition (WSDL of the REST message specification) is obtained for the REST message transmission source system, and the difference is stored as an additional WSDL definition in the WSDL database 15 for the REST message transmission source system.

  In addition, the processing determination unit 13 stores the processing state (state) of the REST message received by the REST API receiving unit 11 in the state management database 16, and further performs state management according to a response from the REST message receiving destination system. The database 16 and the policy database 17 are referred to and subsequent processing is executed. The process in the process determination unit 13 will be described in detail later.

  The REST API transmission unit 14 transmits a REST message and a processing result inside the WSP 10.

  The WSDL database 15 pre-specifies the REST message used in the transaction using the framework of WSDL 2.0 (or later) and stores it in advance as a WSDL definition for each REST message transmission source system. The difference obtained by the above is stored as an additional WSDL definition corresponding to the REST message source system. The common part of the WSDL definition for each REST message source system may be stored in common. The REST message includes the URL of the Web service, the operation command, and the structure of the REST message.

  The state management database 16 stores transaction state transitions, REST messages, and information on their WSDL definitions. This information includes the operation command sent by WSP10, its WSDL definition (message content), the response from the receiving system to the operation command sent by WSP10 (normal response, exception (error) reply, no response), Includes receiver group and state transition history (normal end, abnormal end sequence).

  The policy database 17 stores a policy for processing that the WSP 10 performs thereafter on the received REST message.

  FIG. 5 is a flowchart showing an example of processing in WSP10. Hereinafter, the process will be described with reference to FIGS.

  First, any one of the systems A to D is a request command transmission source system and the other one is a request command reception destination system, and a request command REST message (hereinafter simply referred to as “request command”) from the request command transmission source system. May be called).

  The WSP 10 receives the request command in S11, converts it into a REST message specification WSDL (WSDL definition) in S12, and gives it to the next process (S13: process determination unit 13) together with the request command. Note that the WSDL is WSDL 2.0 (or later) that can convert REST messages. The above is the processing performed by the REST API reception unit 11 and the WSDL generation unit 12.

  The following is a process performed by the process determination unit 13. The process determination unit 13 first determines whether or not the REST message is an exception message, that is, an error message, in S13. In this case, since the REST message is a request command and not an error message, it is determined in S13 that it is not an exception message. Therefore, in this case, the request command and its WSDL definition are given to S14.

  In S14, the WSDL definition stored in advance in the WSDL database 15 is compared with the WSDL definition generated by the WSDL generation unit 12. Since this comparison processing is not processing when an error message is received, it is described here as comparison processing (normal system).

  In the WSDL database 15, a WSDL definition of a REST message used in a transaction is configured in advance and stored for each REST message transmission source system. Comparison of WSDL definitions and addition of WSDL definitions described later are performed for the REST message source system.

  After the comparison process (normal system) in S14, in S15, it is determined whether or not there is a difference as a result of the comparison process. If it is determined that there is no difference, the process proceeds to S18. In S18, final processing determination is performed according to the policy stored in the policy database 17 in advance.

  The policy database 17 stores a policy that, when the received REST message is a request command, it is transferred to the request command receiving system without changing the contents. Therefore, in this case, the request command is transferred to the request command receiving destination system through S14, S15, S18, and S19 without changing the contents. At this time, the result of the final processing determination in S18 is stored in the state management database 16 as a transition history together with the request command transmission source and destination system pair, the request command and its WSDL definition.

  When the API specification of the request command transmission source system is expanded, it is determined in S15 that there is a difference. In this case, the difference is stored as an additional WSDL definition for the WSDL definition stored in the WSDL database 15. From the WSDL definition stored in the WSDL database 15, the specifications that can be handled when the REST message source system is the receiving side can be understood.

  Next, comparison processing (normal system) is performed again in S14. As a result of this comparison processing (normal system), since it is determined that there is no difference in S15, the request command is transferred to the request command receiving system through S14, S15, S18, S19 without changing the contents. At this time, together with the request command and its WSDL definition, the result of the final processing determination in S18 is stored in the state management database 16 as a transition history. Note that the processing up to S18 described above is processing performed by the processing determination unit 13, but S19 is processing performed by the REST API transmission unit 14.

  As described above, if the WSDL definition in the request command is the same as the WSDL definition stored in advance in the WSDL database 15, the WSP 10 transfers the request command to the request command receiving system without changing the contents. If the API specification of the request command source system is expanded and the WSDL definition in the request command is different from the WSDL definition stored in advance in the WSDL database 15, the difference is stored in the WSDL definition file of the WSDL database 15. After the addition, the request command is transferred to the request command receiving system without changing the contents. At this time, the WSDL database 15 stores the updated WSDL definition of the API specification of the request command transmission source system. In addition, the state management database 16 stores the result of the final process determination as a transition history together with the request command transmission source and destination system pair, the request command and its WSDL definition.

  The request command receiving system receives the request command, returns a normal response REST message if it can be understood, and returns an exception (error) REST message if it cannot be understood. In some cases, no response is returned.

  If the REST message receiving system can understand the received REST message, it returns a normal response REST message. Therefore, when the request command receiving system can understand the request command, a normal response REST message (hereinafter sometimes simply referred to as “normal response”) is returned.

  In this case, the WSP 10 receives the normal response, does not perform the processing of S12, S14, and S15 for the normal response, and gives the normal response as it is to the final processing determination (S18). That is, the normal response is transferred to the request command transmission source system through S14, S15, S18, and S19 without changing the contents. In order to perform this process, the policy database 17 stores a policy that when a normal response is received, the content is not changed but transferred to the request command transmission source system. At this time, the state management database 16 stores the result of the final processing determination as a transition history together with the normal response and the pair of the request command transmission source and the reception destination system so that the correspondence with the request command can be understood.

  As described above, the WSP 10 transfers the normal response to the request command transmission source system without changing the contents. At this time, the result of the final process determination is stored as a transition history in the state management database 16 together with the contents of the REST message and the pair of request command transmission source and reception destination (response transmission source) systems.

  If the REST message receiving system does not understand the received REST message, it returns an exception (error) REST message. Therefore, when the request command receiving destination system cannot understand the request command, an exception (error) REST message (hereinafter sometimes simply referred to as “error message”) is returned from the request command receiving destination system.

  In this case, in S13, since the received REST message is determined as an exception, the process proceeds to S16. In S16, WSDL rollback processing is performed. WSDL rollback processing means processing to delete the additional WDSL definition based on the REST message in the previous procedure that caused the exception (error). This WSDL rollback process generates the WSDL definition before addition based on the REST message of the previous procedure that caused the exception (error). The WSDL definition stored in the WSDL database 15 for the request command transmission source system is for managing specifications that can be handled when the request command transmission source system is the receiving side, and is updated. There is no need.

  Then, in S17, the WSDL definition of the REST message in the previous step is compared with the WSDL definition after the WSDL rollback process. That is, the request command's WSDL definition is compared with the prior WSDL definition. Since this comparison processing is processing when an error message is received, it is referred to as comparison processing (abnormal system) here.

  Next, it progresses to S18 and a final process determination is performed. The policy database 17 also stores a policy when the received message is an exception. In S18, final processing determination is performed according to the policy stored in the policy database 17.

  FIG. 5 also illustrates a policy assuming that parameters are added / changed by extending the API specification, or that the request command itself is not supported by extending the API specification.

  Specifically, when an error message is received, the WSP10 performs the following operations: (1) If the difference is one parameter, transfer the request command with the parameter deleted to the request command receiving system, (2) Difference If there are two parameters, refer to the WSDL database 15 and the state management database 16 and transfer the request command to a system with two or fewer differences. (3) If the difference is three or more parameters, the request command source system will receive an exception. Return (unsupported parameter) REST message, (4) If the request command itself is not supported, transfer the request command to a system that can support it, and if there is no such system, send an exception (unsupported parameter) request command It is determined that it will be returned to the original system. Whether the system can support the request command can be determined by referring to the WSDL database 15.

  In the case of (1), in S18, one parameter of the difference is deleted from the REST message of the request command in the previous procedure, and the request command is transferred to the request command receiving system through S19. Thereby, it can be expected that a normal response is returned from the request command receiving system. However, if an error message is still returned, an error may be returned to the request command transmission source system.

  In the case of (2), the request command is transferred to the system having two or less differences through S18 and S19. This is because there is a relatively high possibility that a system with two or less differences will respond normally. If an error message is still returned, an error may be returned to the request command source system.

  In the case of (3), an error message is returned to the request command transmission source system because any system is unlikely to respond normally.

  In the case of (4), there is a high possibility that a normal response is returned from a system that can support the request command. Therefore, the request command is transferred to the system through S18 and S19, and if no normal response is returned from any system, an error message is returned to the request command transmission source system.

  If the request command receiving system does not return any response even after sending the request command, it is not supported by the request command sending system according to the policy stored in the policy database 17 for “no response”. Returns an error message. This can be realized by interrupt processing. For example, the elapsed time after sending the request command in the status management database 16 is counted with a timer. return it. Also in the above case, the state management database 16 accumulates a pair of request command transmission source and reception destination systems, responses, and results of final processing determination as a transition history.

  Although the embodiment has been described above, the present invention is not limited to the above embodiment. For example, although the policy is specifically illustrated in FIG. 5, the policy is merely an example, and the policy may be determined so as to include at least one of (1), (2), and (4). In other words, when an error message is received in response to a request command, the request command whose specification is partially changed is transferred to the request command receiving application server according to a preset policy (in the case of (1)) or received. If the policy includes a process of transferring the requested command to an application server that may respond to the request command (in the case of (2) or (4)), the extensibility of the API specification can be dealt with.

  Further, the policy may be determined according to not only the parameters and commands but also the difference in the number of arguments, and the policy may be variably set as appropriate.

  In the above embodiment, the present invention is realized as a Web service system including WSP10. However, the present invention is not limited to the processing method in WSP10, that is, the Web service message mediation method in WSP10 and WSP10. It can also be realized as a configuration. In the above embodiment, the Web service message exchanged between the systems is the REST message. However, the present invention can also be applied to other Web service messages such as a SOAP message.

  10 ... WSP, 11 ... REST API receiver, 12 ... WSDL generator, 13 ... Processing determination unit, 14 ... REST API transmitter, 15 ... WSDL database, 16 ...・ State management database, 17 ... Policy database

Claims (6)

Multiple application servers that perform various functions;
A proxy server that mediates a Web service message exchanged between the plurality of application servers,
Each of the plurality of application servers includes a program and an API for executing the respective functions,
The proxy server, upon receiving the Web service message from the application server, if it is a request command is transferred to the request command receiver Application areas Activation server without changing its contents, receives a normal response message thereto If you were transferred to the request command source application areas Activation server without changing its contents, when receiving an error message to the request command, it is preset according to the change of the WSDL definition for the request command selected according to the policy, or to forward the request command, which is a partial modification of the specifications in the request command receiver application areas Activation server, the request command received, or transferred to application areas Activation server that might respond to it, the JP that has a function of executing manner W eb service system shall be the. A web service message mediation method in a web service system composed of a plurality of application servers,
A first step of receiving a web service message;
A second step of generating a WSDL definition in the web service message received by the first step;
A third step of making a process decision;
A fourth step that sends Web service message according to the determination result in the third step,
The third step, when receiving the Web service message from the application server, if it is a request command is transferred to the request command receiver Application areas Activation server without changing its contents, normal response message thereto is received, and forwards the request command source application areas Activation server without changing its contents, when receiving an error message to the request command, preset according to the change of the WSDL definition for the request command following a policy, whether to forward the request command, which is a partial modification of the specifications in the request command receiver application areas Activation server, the request command received, whether to forward the app Ke Activation server that might respond to it , We, characterized by selectively executed Service message mediation method. A proxy server for a web service system composed of a plurality of application servers,
When receiving the Web service message from the application server, if it is, if the request command, which forwards the request command receiver Application areas Activation server without changing its contents, receives a normal response message thereto, the contents transferred to the request command source application areas Activation server without changing, when receiving an error message to the request command, according to the policy that is set in advance according to the change of the WSDL definition for the request command, the specification either forward the request command obtained by partially modifying the request command receiver application areas Activation server, the request command received, selectively ability to run, or transferred to application areas Activation server that might respond to it Proxy server characterized by having A receiving unit for receiving a web service message;
Among the Web service messages received by the reception unit, a W SD L generation unit that generates a WSDL definition for a request command;
A process determination unit;
A transmission unit that transmits a Web service message according to a determination result by the processing determination unit;
The WSDL definitions generated by the W SD L generation unit, and WSDL database storing update the WSDL definitions stored in advance for each request command sending application server,
A state management database that accumulates determination results in the processing determination unit together with transaction state transitions;
A policy database for storing a web service message received by the receiving unit and a policy of an operation to be performed on the web service message;
The process determination unit calculates a difference between the WSDL definition before update stored in advance in the WSD L database for each request command transmission source application server and the WSDL definition generated by the WSDL generation unit. The WSDL is updated in response to the application server, and the difference is stored as an additional WSDL definition in the WSDL database for each request command source application server, and the state management database is updated with the processing result along with the transaction state transition. is accumulated, and further, when receiving the Web service message, if it is a request command, is transferred to the request command receiver application areas Activation server without changing its contents, it receives a normal response message thereto If the request command transmission is forwarded to the original Application areas Activation server without changing its contents, when receiving an error message to the request command, a preset policy in response to a change in the WSDL definition for the request command according, Luke is transferred specifications request command receiver application areas Activation server request command, which is a partial modification of the, or the request command received, is transferred to the application Ke Activation server that might respond to it, select 4. The proxy server according to claim 3, wherein the proxy server is executed automatically. The policy for the parameters of the request command, if the difference is one, is transferred a request command that deletes the parameter request command receiver Application areas Activation server, if the difference is two, the difference is 2 or less is set so as to transfer the request command to the application Ke Activation server, the request command itself, required when the command itself is unsupported, the request command, is set so as to forward it to supportable application areas Activation server The proxy server according to claim 4 , wherein:   The proxy server according to claim 5, wherein the policy further sets transfer of a request command or a request command in which a specification is partially changed in accordance with a difference in the number of arguments of the request command.