Abstract:
Computer-executable code is automatically generated for a message flow in a message queuing infrastructure by determining a type of the message flow, inputting message flow parameters, and generating the computer-executable code based on the type of the message flow and the message flow parameters. The generation of code can also implement a design pattern, which is input based on the determined type of message flow. The computer-executable code can be, for example, Extended Structured Query Language (ESQL) code. The type of the message flow can identify, for example, a transformation requirement of the message flow. The transformation requirement can be, for example, one of (i) transformation from a first Extensible Markup Language (XML) message to a second XML message, (ii) transformation from an XML message to a Message Repository Manager (MRM) message, and (iii) transformation from a first MRM message to a second MRM message.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of, claims priority to and the benefit of, U.S. Ser. No. 13/618,418 filed Sep. 14, 2012 and entitled “SYSTEM AND METHOD FOR AUTOMATICALLY GENERATING COMPUTER CODE FOR MESSAGE FLOWS.” The &#39;418 application is a continuation of, claims priority to and the benefit of, U.S. Ser. No. 11/862,463 filed Sep. 27, 2007 and entitled “SYSTEM AND METHOD FOR AUTOMATICALLY GENERATING COMPUTER CODE FOR MESSAGE FLOWS,” which issued as U.S. Pat. No. 8,286,189 on Oct. 9, 2012. All of these applications are hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention generally relates to message flows in a message queuing infrastructure, and more particularly to a system and method for automatically generating computer code for message flows. 
         [0004]    2. Related Art 
         [0005]    The information technology infrastructure of a large business can encompass a variety of different technologies, including different hardware platforms, programming languages, operating systems, and communication protocols. Middleware helps to form these different technologies into a coherent system by providing a common layer to bridge components across the infrastructure. Message queuing is a type of middleware technology that simplifies communication between the components, or nodes, of a system. A node is any point in the system that provides a service, requests a service, or connects nodes together. 
         [0006]    Message queuing middleware, such as IBM WebSphere® MQ (WMQ) and IBM WebSphere® MQ Integrator (WMQI), provides integration for applications and Web services by allowing software applications to provide and request services residing on different nodes through the use of messages. Nodes send information and request services by sending messages to other nodes. Specifically, a message from a source node is placed in an input queue of a message broker. The message broker retrieves the message from the input queue, parses the message, and executes operations (e.g., transformation and routing) according to a message flow associated with the message. Once the operations of the message flow are completed for the message, the broker delivers the message to one or more output queues for retrieval by one or more destination nodes. 
         [0007]    A message flow is a collection of nodes that provide small, reusable pieces of functionality for transmitting the message. Specifically, the nodes of a message flow define the series of operations and rules that the message broker executes for a message. Using message flows to communicate messages provides several advantages, particularly in a large enterprise infrastructure built on different technologies. For example, message flow nodes can be created to allow the broker to transform an input message in one format (e.g., Extensible Markup Language (XML)) to an output message in another format (e.g., MRM message). This ability to transform the format of a message facilitates communication between nodes that use different message formats. Message flow nodes can also be created to allow the broker to route an input message by, for example, setting destination queues and appending additional information to the message. 
         [0008]    Generally, creating nodes for a message flow requires a human operator to write and test computer code. For example, WMQI allows users to create user-written nodes by inputting Extended Structured Query Language (ESQL) code into a node. ESQL is an extended version of Structured Query Language (SQL), which is a standard interactive and programming language for getting information from and updating a database. Although SQL is both an ANSI and an ISO standard, many database products support SQL with proprietary extensions to the standard language. Queries take the form of a command language that provides the ability to select, insert, update, find out the location of data, and so forth. SQL also includes a programming interface. Particularly, SQL includes a Microsoft Open Database Connectivity (ODBC) compatible interface, which allows custom applications to be built using a wide variety of programming tools or to query databases using existing ODBC-compliant applications. 
         [0009]    In typical enterprise middleware infrastructure projects, the build time for each message flow node (in WMQI) can be relatively long. Thus development time for each message flow increases. In addition, maintaining consistency of the computer code written for different message flows from one project to another can be difficult. Moreover, errors in writing code for one project can be copied into code written for another project, causing the same defects to be repeated in the resulting message flows, which in turn increases development time due to re-work. Furthermore, it is often the case that the same or similar code written for one project cannot easily be used for another project due to the lack of knowledge of the existence of the already written code, which can result in duplication of effort. 
         [0010]    Given the foregoing, what is needed is a system, method and computer program product for automatically generating computer code for message flows. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0011]    The present invention meets the above-identified needs by providing a system, method and computer program product for automatically generating computer code for message flows. 
         [0012]    An advantage of the present invention is that it speeds up development of message flows. 
         [0013]    Another advantage of the present invention is that it improves productivity, particularly in situations with complex message flows having large numbers of fields that require mapping. 
         [0014]    Yet another advantage of the present invention is that it reduces human errors and hence reduces defects during integration testing and user acceptance testing. 
         [0015]    Still another advantage of the present invention is that it reduces development costs and time to market for developers of message flows and hence reduces the overall cost for integrating a business information technology infrastructure. 
         [0016]    In one aspect of the present invention, computer-executable code is automatically generated for a message flow in a message queuing infrastructure. A type of the message flow is determined form user input. For example, a user can select from among a plurality of message flow types displayed on a graphical user interface. Message flow types can be selected, for example, for scenarios in which an XML application requests a service from a COBOL application, a COBOL application requests a service from an XML application, and an XML application requests a service from an XML application. Message flow parameters are input, for example, using a submenu of the graphical user interface. The computer-executable code for the message flow is automatically generated based on the determined type of the message flow and the input message flow parameters. For example, using the user&#39;s inputs, a computer can automatically generate ESQL script for use in the desired message flow. 
         [0017]    In another aspect of the invention, a design pattern is input based on the determined type of message flow, and the computer-executable code generation is further based on the design pattern. 
         [0018]    In still another aspect of the invention, the type of the message flow identifies a transformation requirement of the message flow based on the message flow parameters. 
         [0019]    In yet another aspect of the invention, the conversion requirement is one of (i) transformation from a first Extensible Markup Language (XML) message to a second XML message, (ii) transformation from an XML message to a Message Repository Manager (MRM) message, and (iii) transformation from a first MRM message to a second MRM message. 
         [0020]    In a further aspect of the invention, the determining the type of message flow includes determining a requestor type of the message flow and a provider type of the message flow, and the type of the message flow is determined based on the requestor type and the provider type. 
         [0021]    In yet another aspect of the invention, the requestor type is one of an Extensible Markup Language (XML) requestor and a Common Business Oriented Language (COBOL) requestor, and the provider type is one of an XML provider and a COBOL provider. 
         [0022]    In another aspect of the invention, a graphical user interface is displayed. The graphical user interface includes data entry fields for the input of the message flow parameters. 
         [0023]    Further features and advantages of the present invention as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit of a reference number identifies the drawing in which the reference number first appears. 
           [0025]      FIG. 1  is a system diagram of an exemplary enterprise system in which computer code generated according to the present invention would be implemented. 
           [0026]      FIG. 2  is a block diagram of an exemplary computer system useful for implementing the present invention. 
           [0027]      FIG. 3  is a flowchart illustrating an ESQL generating process according to one embodiment of the present invention. 
           [0028]      FIG. 4  is a screenshot of a graphical user interface according to one embodiment of the present invention. 
           [0029]      FIG. 5  is another screenshot of a graphical user interface according to one embodiment of the present invention. 
           [0030]      FIG. 6  is another screenshot of a graphical user interface according to one embodiment of the present invention. 
           [0031]      FIG. 7  is a system diagram illustrating an exemplary multi-hub architecture used by an exemplary design pattern of one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
     I. Overview 
       [0032]    The present invention is directed to a system, method and computer program product for automatically generating computer code for message flows. Message flows are commonly utilized by enterprise systems implementing message queuing middleware. A common architecture of such an enterprise system is the so-called hub-and-spoke architecture. Hub-and-spoke architectures consist of a centralized hub that accepts requests from multiple applications that are connected to the centralized hub as spokes. The spokes are generally connected with the central hub through lightweight connectors, which are constructed and deployed on top of existing systems and applications. 
         [0033]    Inside the hub there are multiple nodes that perform functions such as message transformation, validation, routing, and asynchronous message delivery. Some hub-and-spoke-based systems provide process management functionality to orchestrate interapplication message exchanges, and an administration console to monitor and track the workings of the hub. 
         [0034]      FIG. 1  is a system diagram of an exemplary enterprise system in which computer code generated by the present invention may be implemented.  FIG. 1  shows a hub and spoke architecture with clients  101   a,    101   b,    101   c  and  101   d  at the spokes and a message broker  103  at the hub. The clients  101   a,    101   b,    101   c  and  101   d  are connected to message broker  103  through network connections  105   a,    105   b,    105   c  and  105   d,  respectively, which allows messages to be communicated between the components of enterprise system  100 . Each client  101   a - d  has WMQ installed and the message broker  103  has both WMQ and WMQI installed. In this configuration, the message broker  103  is used for transforming messages into alternate formats and routing the messages to the various clients  101   a - d  in accordance with message flows. 
         [0035]    The present invention is now described in more detail herein in terms of exemplary embodiments that generate ESQL scripts to be used in message flows implemented in the enterprise system of  FIG. 1 . In particular, the exemplary embodiments generate ESQL scripts for transforming and routing messages transmitted among XML applications and COBOL applications in the enterprise system. The use of exemplary embodiments of the present invention is for convenience only and is not intended to limit the application of the present invention. In fact, after reading the following description, it will be apparent to one skilled in the relevant art(s) how to implement the following invention in alternative embodiments (e.g., generating computer code to be used in message flows for performing other operations, such as filtering messages, adding data to messages, subtracting data from messages, and storing messages, the messages being transmitted among applications built on a wide variety of platforms, operating systems, communication protocols, and programming languages, implemented with different message queuing middleware such as Microsoft® Message Queuing Server, Oracle® Advanced Queuing, and Apache® ActiveMQ, which operate within different enterprise system architectures, such as queue manager clusters, message bus, etc., and for other types of requesting applications, such as BLOB messages). 
         [0036]    The terms “user,” “end user,” “consumer,” “customer,” “operator,” and/or the plural form of these terms are used interchangeably throughout herein to refer to those persons or entities capable of accessing, using, being affected by and/or benefiting from the tool that the present invention provides for automatically generating computer code for message flows. 
         [0037]    Furthermore, the terms “business” or “merchant” may be used interchangeably with each other and shall mean any person, entity, distributor system, software and/or hardware that is a provider, broker and/or any other entity in the distribution chain of goods or services. For example, a merchant may be a grocery store, a retail store, a travel agency, a service provider, an on-line merchant or the like. 
       II. System 
       [0038]      FIG. 2  is a system diagram of an exemplary computer system  200  in which the present invention, in an embodiment, would be implemented. Computer system  200  can be a client  101  in enterprise system  100 , or can be a stand-alone computer system. 
         [0039]    The computer system  200  includes one or more processors, such as processor  204 . The processor  204  is connected to a communication infrastructure  206  (e.g., a communications bus, cross-over bar, or network). The processor  204  executes software code stored in one of a plurality of memories, described more fully below. Various software embodiments are described in terms of this exemplary computer system. After reading this description, it will become apparent to a person skilled in the relevant art(s) how to implement the invention using other computer systems and/or architectures. 
         [0040]    Computer system  200  can include a display interface  202  that forwards graphics, text, and other data from the communication infrastructure  206  (or from a frame buffer not shown) for display on a display unit  230 . 
         [0041]    Computer system  200  also includes a main memory  208 , preferably random access memory (RAM), and may also include a secondary memory  210 . The secondary memory  210  may include, for example, a hard disk drive  212  and/or a removable storage drive  214 , representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive  214  reads from and/or writes to a removable storage unit  218  in a well-known manner. Removable storage unit  218  represents a floppy disk, magnetic tape, optical disk, etc. which is read by and written to by removable storage drive  214 . As will be appreciated, the removable storage unit  218  includes a computer usable storage medium having stored therein computer software and/or data. 
         [0042]    In alternative embodiments, secondary memory  210  may include other similar devices for allowing computer programs or other instructions to be loaded into computer system  200 . Such devices may include, for example, a removable storage unit  222  and an interface  220 . Examples of such may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an erasable programmable read only memory (EPROM), or programmable read only memory (PROM)) and associated socket, and other types of removable storage units  222  and interfaces  220 , which allow software and data to be transferred from the removable storage unit  222  to computer system  200 . 
         [0043]    Computer system  200  may also include a communications interface  224 . Communications interface  224  allows software and data to be transferred between computer system  200  and external devices. Examples of communications interface  224  may include a modem, a network interface (such as an Ethernet card), a communications port, a Personal Computer Memory Card International Association (PCMCIA) slot and card, etc. Software and data transferred via communications interface  224  are in the form of signals  228  which may be electronic, electromagnetic, optical or other signals capable of being received by communications interface  224 . These signals  228  are provided to communications interface  224  via a communications path (e.g., channel)  226 . This channel  226  carries signals  228  and may be implemented using wire or cable, fiber optics, a telephone line, a cellular link, a radio frequency (RF) link and other communications channels. 
         [0044]    In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage drive  214 , a hard disk installed in hard disk drive  212 , and signals  228 . These computer program products provide software to computer system  200 . The invention is directed to such computer program products. 
         [0045]    In one embodiment, computer programs (also referred to as computer control logic) are stored in main memory  208  and/or secondary memory  210 . Computer programs may also be received via communications interface  224 . Such computer programs, when executed, enable the computer system  200  to perform the various features of the present invention, as discussed herein. In particular, the computer programs, when executed, enable the processor  204  to perform features of the present invention. Accordingly, such computer programs represent controllers of the computer system  200 . 
         [0046]    In the present embodiment, the invention is implemented using software. The software may be stored in a computer program product and loaded into computer system  200  using removable storage drive  214 , hard drive  212  or communications interface  224 . The control logic (software), when executed by the processor  204 , causes the processor  204  to perform the functions of the invention as described herein. 
         [0047]    To generate computer code for message flows according to the present embodiment, a user executes the software on computer system  200 . Communications interface  224  can allow the user to upload the generated computer code to the enterprise system  100  of  FIG. 1 , for use in message flows implemented by enterprise system  100 . 
       III. Process 
       [0048]      FIG. 3  is a flowchart illustrating a computer code generating process  300 , according to one embodiment of the present invention. Specifically, the present embodiment generates ESQL scripts for use in a message flow. 
         [0049]    Process  300  begins when a user identifier (ID), which has previously been stored in a registry, is obtained ( 301 ) from the registry. The user is prompted ( 302 ) to enter a password corresponding to the user ID. A determination is made ( 303 ) whether the user ID and password are valid. If the user ID or password could not be validated, then a determination is made ( 304 ) as to whether too many login attempts, for example, more than three, have been made. If not, then process  300  again prompts ( 302 ) the user for a password. However, if too many login attempts have been made, the application is closed ( 305 ) and process  300  ends. If the user ID and password are validated, a determination is made ( 306 ) as to whether the latest version of the software application in accordance with the present embodiment of the invention is being used. If not, the user is prompted ( 307 ) to install the latest version of the application. If the latest version of the application is in use, a selection is made ( 308 ) of the type of format transformation required for a message. 
         [0050]    In the present embodiment, the transformation type is selected by the user based on the type of format transformation, if any, that is required for a message from an application requesting a service to an application providing the service. A code generator is set corresponding to the selected transformation type, and message flow parameters are then input by the user. An example of how the user selects the transformation type and inputs message flow parameters will now be described in reference to  FIGS. 4 ,  5  and  6 . 
         [0051]      FIG. 4  is a screenshot of a menu  401  of an exemplary software embodiment of the present invention displayed on display unit  230  at step  308 . Menu  401  includes tabs for the selection of a transformation type  403 . The transformation types of the present embodiment are “XML To XML”, “MRM Request To XML”, and “XML To MRM Request”. For a request message from an XML application to another XML application, in which no format transformation is required, the user selects the “XML To XML” tab, and then inputs corresponding message flow parameters. Specifically, the user inputs a flow type  405  as “Request” or “Reply,” hub hopping information  407  as “App Hub” or “Service Hub,” a hub name  409 , a reply to queue  411 , and an XML envelope version  413 . 
         [0052]    Referring again to  FIG. 3 , after the user completes the user inputs, and selects the “Generate Script” button of menu  401 , a code generator for XML to XML ( 309 ), which corresponds to the user selected “XML To XML” tab, accepts ( 310 ) the message flow parameters from menu  401 , and generates ESQL script ( 311 ) for routing operations. 
         [0053]    In a like manner, the user can select a tab for “XML To MRM Request” of menu  401 . Thus,  FIG. 5  is a screenshot of a menu  501  of the exemplary software embodiment of the present invention displayed on display unit  230  at step  308 . For a request message from an XML application to a COBOL application, the user sets transformation type  403  by selecting the “XML To MRM Request” tab, and then inputs corresponding message flow parameters. In the present embodiment, messages sent to and received from COBOL applications are formatted as MRM messages. Specifically, the message flow parameters the user inputs are flow type  405  as “Request” or “Reply,” hub name  409 , reply to queue  411 , XML envelope version  413 , an MQ header type  503 , a COBOL format  505 , and an XML format  507 . 
         [0054]    Referring again to  FIG. 3 , after the user completes the user inputs, and selects the “Generate Script” button of menu  501 , a code generator for XML to MRM ( 312 ), which corresponds to the user selected “XML To MRM Request” tab, accepts ( 313 ) the message flow parameters from menu  501 , and generates ESQL script ( 311 ) for routing operations and transformation operations. 
         [0055]    In a like manner, the user can select a tab for “MRM Request To XML” of menu  401 . Thus,  FIG. 6  is a screenshot of a menu  601  of the exemplary software embodiment of the present invention displayed on display unit  230  at step  308 . For a request message from a COBOL application to an XML application, the user sets transformation type  403  by selecting the “MRM Request To XML” tab, and then inputs corresponding message flow parameters. Specifically, the user inputs flow type  405  as “Request” or “Reply,” hub name  409 , reply to queue  411 , XML envelope version  413 , COBOL format  505 , XML format  507 , and a latest copybook format  603 . 
         [0056]    Referring again to  FIG. 3 , after the user completes the user inputs, and selects the “Generate Script” button of menu  601 , a code generator for MRM to XML ( 314 ), which corresponds to the user selected “MRM Request To XML” tab, accepts ( 315 ) the message flow parameters from menu  501 , and generates ESQL script ( 311 ) for routing operations. 
         [0057]    After ESQL script has been generated, the application closes ( 305 ) and process  300  ends. 
         [0058]    In order to generate ESQL script for transformation and routing of a message, the code generators  309 ,  312 , and  314  of the present embodiment implement a design pattern. While the use of a design pattern is not required, and the invention is not limited the use of a design pattern, the automatic generation of code according to a design pattern can provide many advantages. In particular, adherence to a design pattern results in more consistent WMQ and WMQI object naming and deployment, which can reduce the time and effort necessary to develop and support all messages flows. In addition, adherence to a design pattern can result in decoupling of components that request and components that provide services. In this regard, the design pattern of the present embodiment provides the code generators with (i) a standard coding practice for WMQ and WMQI objects, (ii) standard application processing requirements to be used in generating the ESQL script, and (iii) standard WMQI processing requirements to be used in generating the ESQL script. 
         [0059]    The exemplary design pattern utilized in the present embodiment employs a logical multi-hub architecture, which is consistent with the current trend of decentralizing the processing in a WebSphere®-implemented enterprise system. In addition, all inter-hub messages are in canonical format and queues carry service names to facilitate redeployment to accommodate component and service changes. Use of the design pattern allows message flow developers and service providers to concurrently support multiple versions of each service message, which helps isolate service providers, message brokers, and requesters from the impact of new service versions. In particular, each can upgrade in an orderly fashion as business requirements dictate. 
         [0060]    In addition, the exemplary design pattern of the present embodiment utilizes generic request and reply queues for applications and services, which can greatly reduce the number of WMQ objects to define and support, which allows new services to be employed by existing applications with minimal or no WMQ changes. Moreover, the use of generic request and reply flows for applications and services can greatly reduce the number of WMQI objects to define and support, which allows existing services to be employed by additional applications with minimal or no WMQI changes. 
         [0061]      FIG. 7  depicts an exemplary multi-hub architecture on which the design pattern of the present embodiment is based. 
         [0062]      FIG. 7  includes a requesting application  701  having the name “REQUESTER,” an application hub  703  having the name “APPHUB,” a service hub  705  having the name “SERVICEHUB,” and a provider application service  707  having the name “PROVIDER.” In this multi-hub architecture, a request message from requesting application  701  is routed through application hub  703  and service hub  705  to provider application service  707 . A reply message from provider application service  707  is routed through service hub  705  and application hub  703  to requesting application  701 . 
         [0063]    In  FIG. 7 , the paths of the messages are shown by the arrowed lines. Specifically, to request a service of provider application  707 , requesting application  701  places a request message in a queue  717 . The request message is routed through application hub  703  and service hub  705  to reach a queue  723  of provider application service  707 . 
         [0064]    When provider application service  707  has completed processing the request message, a reply message is routed through service hub  705  and application hub  703  to reach a queue  729  of requesting application  701 . 
         [0065]    The exemplary design pattern of the present embodiment provides a standard pattern for generating ESQL script for each portion of a request message flow, which includes a service request  731  from a requester, a request flow  733  on an application hub, a request flow  735  on a service hub, and a service request  737  to a provider. The exemplary design pattern of the present embodiment also provides a standard pattern for generating ESQL script for each portion of a reply flow, which includes a service reply  739  from a provider, a reply flow  741  on a service hub, a reply flow  743  on an application hub, and a service reply  745  to a requester. The message flows can include subflows, which define additional operations to be performed on a message. For example, subflows can be used for message format transformation. In addition, the message flows can include operations to set the destination of a message 
         [0066]    In the present embodiment, requesting application  701  can be an XML application or a COBOL application. Likewise, provider application service  707  can be an XML application or a COBOL application. The particular combination of type of requesting application  701  and type of provider service application  707  is used to determine which code generator  309 ,  312 , or  314  will be used to generate ESQL script for a message flow. In this regard, the operation of the code generators  309 ,  312 , and  314 , and the implementation of the exemplary design pattern, will now be described with respect to particular combinations of types of requesters and providers. 
         [0000]    XML requester—XML provider: 
         [0067]    If both requesting application  701  and provider application service  707  are XML applications, XML to XML code generator  309  is used to generate ESQL script. Code generator  309  utilizes two XML to XML design patterns to generate ESQL script, a request message flow design pattern and a reply message flow design pattern. 
         [0068]    When the flow type  405  selected by the user is “Request,” the XML to XML design pattern according to a request message flow is implemented by code generator  309  to generate ESQL script for request flow  733  on the application hub and request flow  735  on the service hub. The generated ESQL script for request flow  733  includes code defining a request queue, reverse routing information of the request message, compute and output nodes, a destination mode, a destination queue name, a reply to queue and a queue manager. The generated ESQL script for request flow  735  includes code defining a service request queue, reverse routing information, an application service provider input queue, and a reply to queue on service hub  705 . 
         [0069]    When the flow type  405  selected by the user is “Reply,” the XML to XML design pattern according to a reply message flow is implemented by code generator  309  to generate ESQL script for reply flow  741  on the service hub and reply flow  743  on the application hub. The generated ESQL script for reply flow  741  includes code defining a service reply queue and routing replies to application hub  703 . The generated ESQL script for reply flow  743  includes code routing replies to requesting application  701 . 
         [0000]    XML requester—COBOL provider: 
         [0070]    If requesting application  701  is an XML application and provider application service  707  is a COBOL application, XML to MRM code generator  312  is used to generate ESQL script. Code generator  312  utilizes two XML to MRM design patterns to generate ESQL script, a request message flow design pattern and a reply message flow design pattern. 
         [0071]    When the flow type  405  selected by the user is “Request,” the XML to MRM design pattern according to a request message flow is implemented by code generator  312  to generate ESQL script for request flow  733  on the application hub and request flow  735  on the service hub. The generated ESQL script for request flow  733  includes code defining a request queue, reverse routing information, compute and output nodes, a destination mode, a destination queue, a reply to queue and queue manager. The generated ESQL script for request flow  735  includes code defining a service request queue, reverse routing information, one or more sub-flows to transform the request from XML to the corresponding version of the COBOL service request message, a reply to queue on service hub  705 , and routing the request to an input queue on provider application service  707 . 
         [0072]    When the flow type  405  selected by the user is “Reply,” the XML to MRM design pattern according to a reply message flow is implemented by code generator  312  to generate ESQL script for reply flow  741  on the service hub and reply flow  743  on the application hub. The generated ESQL script for reply flow  741  includes code defining a service reply queue, one or more sub-flows to transform the reply from COBOL to the corresponding version of the XML service reply message, and routing replies to application hub  703 . The generated ESQL script for reply flow  743  includes code routing replies to requesting application  701 . 
         [0000]    COBOL requester—XML provider: 
         [0073]    If requesting application  701  is a COBOL application and provider application service  707  is an XML application, MRM to XML code generator  314  is used to generate ESQL script. Code generator  314  utilizes two MRM to XML design patterns to generate ESQL script, a request message flow design pattern and a reply message flow design pattern. 
         [0074]    When the flow type  405  selected by the user is “Request,” the MRM to XML design pattern according to a request message flow is implemented by code generator  314  to generate ESQL script for request flow  733  on the application hub and request flow  735  on the service hub. The generated ESQL script for request flow  733  includes code defining a request queue, reverse routing information, one or more sub-flows to route requests to a corresponding service request queue on service hub  705 , a reply to queue and queue manager. The generated ESQL script for request flow  735  includes code defining a service request queue, reverse routing information, and a reply to queue on service hub  705 , and routing requests to an input queue on provider application service  707 . 
         [0075]    When the flow type  405  selected by the user is “Reply,” the MRM to XML design pattern according to a reply message flow is implemented by code generator  314  to generate ESQL script for reply flow  741  on the service hub and reply flow  743  on the application hub. The generated ESQL script for reply flow  741  includes code defining a service reply queue, and routing replies to application hub  703 . The generated ESQL script for reply flow  743  includes code defining a reply queue, one or more sub-flows to route reply messages back to the requesting application  701  and to transform the XML reply to the corresponding COBOL copybook of the service reply. 
         [0076]    By using the above exemplary design patterns, the code generators of the present embodiment can generate consistent ESQL code for use in message flows. However, the foregoing design pattern is merely one example, and one skilled in the art would recognize that other design patterns, or none at all, could be used. 
       IV. Example Implementations 
       [0077]    The present invention (i.e., computer system  200 , process  300 , or any part(s) or function(s) thereof) may be implemented using hardware, software or a combination thereof and may be implemented in one or more computer systems or other processing systems. However, the manipulations performed by the present invention were often referred to in terms, such as adding or comparing, which are commonly associated with mental operations performed by a human operator. No such capability of a human operator is necessary, or desirable in most cases, in any of the operations described herein which form part of the present invention. Rather, the operations are machine operations. Useful machines for performing the operation of the present invention include general purpose digital computers or similar devices. 
         [0078]    In another embodiment, the invention is implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s). 
         [0079]    In yet another embodiment, the invention is implemented using a combination of both hardware and software. 
       V. Conclusion 
       [0080]    While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope of the present invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. 
         [0081]    In another embodiment, the invention is implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s). 
         [0082]    In yet another embodiment, the invention is implemented using a combination of both hardware and software. 
         [0083]    In addition, it should be understood that the figures and screen shots illustrated in the attachments, which highlight the functionality and advantages of the present invention, are presented for example purposes only. The architecture of the present invention is sufficiently flexible and configurable, such that it may be utilized (and navigated) in ways other than that shown in the accompanying figures. 
         [0084]    Further, the purpose of the foregoing Abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is not intended to be limiting as to the scope of the present invention in any way. It is also to be understood that the steps and processes recited in the claims need not be performed in the order presented.