JP2000076070A - Client/server system and computer readable recording medium recording component link program for providing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a client/server system or the like capable of improving the independence, maintainability and change easiness of respective components. SOLUTION: A supervisory and control system (client/server system) is provided with client processes 100 and 100, a server process 200 and an assistant server process 300 and performs prescribed processing by linking plural clients 101 included in the respective client processes 100 and a server 201 included in the server process 200. The plural clients 101 and server 201 are connected through an assistant server 301 as a relay component and the assistant server 301 interchanges communication between the respective clients 101 and the server 201 and interchanges communication between the respective clients 101 independently of the server 201.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a client server system for performing predetermined processing by linking a plurality of independent components, and more particularly to a client server system for performing predetermined processing by linking a client and a server as components. The present invention relates to a computer-readable recording medium on which a component cooperation program for realizing the system is recorded.

[0002]

2. Description of the Related Art In the development of a system using an object-oriented technology, in order to improve the maintainability and easiness of change of the system, a part of the system where specification changes frequently occurs and is hardly affected by the specification change. It is common to separate parts and develop them as separate components. In the system developed in this way, one system is composed of a plurality of components, and therefore, when executing the system, it is necessary to perform predetermined processing in cooperation with each component.

Conventionally, as a method of linking a plurality of components, there are (1) a method in which each component communicates directly with each other by referring to each other (information indicating an object to be a communication partner in a memory space); (2) A method has been proposed in which a component for bundling each component is newly added, and communication is performed between the components via the newly added component (Reference 1 (Erich Gamma, Richard)
Helm, Ralph Johnson, and John Vlissides.Design Pa
tterns: Addison-Wesley Publishing Company, 1995.)
Detailed). In the method (2) of the conventional methods described above, since each component does not need to have a reference to each other, the complexity of direct communication between the components as in the method (1) is reduced. Can be avoided.

[0004] Note that "reference" is a concept that can be rephrased as a pointer or a reference, and specifically refers to information indicating an object to be a communication partner in the memory space as described above. When the object (A) accesses another object (B), the object (A) needs to have a reference to the object (B). Here, "the object (A) has a reference to the object (B)" means that, in a program, an instance of the type name of the object (B) (a class or an interface for generating the object (B)) is the object (A). It is used in.

[0005]

As described above, in the related art, there is a method of adding a component for bundling each component and communicating between the components via the newly added component. Proposed.

However, such a conventional method is
This is based on the premise that a plurality of components having the same interface cooperate, and no consideration is given to the coordination of a plurality of components (client and server) having different interfaces as in a client-server system.

[0007] The present invention has been made in view of such a point, and by making the client and the server as independent components effectively cooperate, the independence, maintainability, and easiness of change of each component are improved. An object of the present invention is to provide a client-server system that can be improved, and a computer-readable recording medium that records a component cooperation program for realizing the system.

[0008]

A first feature of the present invention is as follows.
In a client-server system that performs a predetermined process by linking a client and a server as independent components, a plurality of clients, a server that executes a process requested by each of the clients, and a server that is connected to each of the clients and the server. A relay component, wherein the relay component relays communication between the clients and the server and relays communication between the clients independently of the server. It is.

A second feature of the present invention is a component cooperation program for realizing a client-server system that performs predetermined processing by linking a client and a server as independent components, and is described in an object-oriented language. A client class that inherits a client interface class that abstracts an interface of a plurality of clients, and a server interface that executes a process requested by each of the clients, on a computer-readable recording medium on which the component cooperation program is recorded. A server class that inherits a server interface class that abstracts the above, and a relay component that inherits both the client interface class and the server interface class A computer-readable recording medium recording a component linkage program, characterized in that it comprises a Toklas.

According to the first and second aspects of the present invention,
Since the relay component relays communication between each client and the server and relays communication between each client independently of the server, a predetermined filtering process can be performed at the time of communication between the client and the server. Since each client does not need to share a reference with each other, the independence of each client can be improved, and maintainability and easiness of change can be improved. further,
Since the server is not used for communication between each client,
The independence between the client and the server is increased, and the load on the server can be reduced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 are views for explaining an embodiment of a client server system according to the present invention. In the present embodiment, as an example of the client server system, a monitoring control system that monitors and controls the moving state of a person, a car, or the like will be described.

First, a hardware environment in which the monitoring control system operates will be described with reference to FIGS.
In FIG. 1, reference numeral 15 denotes a vehicle such as a golf course cart or a patrol car in a park, and reference numeral 10 denotes each of these vehicles 1.
A central control room 10 for centrally controlling a target 5 by a plurality of monitoring personnel. Here, the central management room 10
A plurality of terminals 11 operated by each monitor,
1 and a management computer 12 connected via a communication path 13. A transceiver 14 and a transceiver 16 are mounted on the management computer 12 and each vehicle 15, respectively.
And monitor information, control signals, and the like. FIG. 2 is a block diagram showing details of the hardware configuration of the terminal 11 and the management computer 12 installed in the central management room 10 shown in FIG. As shown in FIG. 2, the terminal 11 includes a processor 21 and a RAM (Rand).
om Access Memory), a large-capacity storage device 23 such as a hard disk unit,
Display device 24 such as T (Cathode Ray Tube)
And an input device 25 such as a mouse and a keyboard, and a communication device 26. These devices are connected to each other via a system bus 27. On the other hand, the management computer 1
2 is a processor 31 and a memory 32 such as a RAM
And a large-capacity storage device 33 composed of a hard disk unit and the like, and a communication device 34. These devices are connected to each other via a system bus 35. The communication device 26 of each terminal 11 and the communication device 34 of the management computer 12 are connected to each other via the communication path 13. The system bus 35 of the management computer 12
Is connected to the transceiver 14.

Next, referring to FIGS. 3 and 4, a monitoring control system that operates on the hardware environment shown in FIGS. 1 and 2 will be described. Here, FIG. 3 is a diagram for explaining the configuration and operation of the monitoring control system, and FIG. 4 is a diagram showing a class configuration when the monitoring control system shown in FIG. 3 is described in an object-oriented language.

As shown in FIG. 3, the supervisory control system comprises:
A client process 100 running on each terminal 11,
100, a server process 200 running on the management computer 12, and an assistant server process 30
0, and a plurality of independent components, that is, a plurality of client objects (hereinafter simply referred to as “clients”) 101 included in each client process 100 and a server object (hereinafter simply referred to as “server”) included in the server process 200. Predetermined processing is performed in cooperation with the server 201. Note that the plurality of clients 101 included in the client process 100 have a single function (the client component 10) in order to localize the influence of the specification change.
3) Each unit is divided.

Here, a plurality of clients 101 and a server 201 that monitors and controls each vehicle 15 in response to a request from each client 101 are connected to an assistant server object (hereinafter simply referred to as “relay component”) included in the assistant server process 300. Assistant Server) 301)
In the assistant server 301, each client 1
01 and the server 201,
The communication between the clients 101 is relayed independently of the server 201.

As shown in FIG. 3, each client 101 and server 201 have a client interface 102 and a server interface 202, respectively, and the assistant server 301 has a client interface 302 and a server interface 303.
have. Here, the assistant server 301 communicates with the client 101 via the server interface 30.
3 and communicates with the server 201 via the client interface 302. From the client 101, as a server,
The server 201 can be used as a client.

FIG. 4 is a diagram showing a class configuration when the monitoring control system shown in FIG. 3 is described in an object-oriented language. In FIG. 4, reference numerals 110 and 210 denote interface classes in which the interfaces of the classes are defined, and only a list of processes (methods) performed in the class (method names, method type names, argument types, and the like) are defined. . Reference numerals 120, 220, and 320 are classes that inherit the interface classes 110 and 210, and define specific processing contents of the processes (methods) defined by the interface classes 110 and 210. In addition,
The objects are of the types of the classes 120, 220, and 320, and the interface classes 110,
210 can also be generated.

Here, reference numeral 110 denotes a client interface class that abstracts the interfaces of a plurality of clients, and specifically relates to, for example, state changes such as the moving speed, position, and orientation of each vehicle 15 sent from the server 201. Method for receiving monitoring information (notifyVe
locity (), notifyPosition (), notifyDirection ()) 1
11 and a method (di) for changing the display method of maps, lists, tables, tables, etc. between the clients 101.
A list of splayMap (), displayList ()) 112 is defined. Reference numeral 210 denotes a server interface class that abstracts a server interface. Specifically, for example, a method 211 for registering and deleting the client 101 as an observer and a method 212 for starting and ending monitoring of each vehicle 15 are provided. , Methods for receiving the monitoring control message sent from each client 101 (startWalking (), stopWalking (), sta
rtRunning (), stopRunning, turnLeft (), turnRigh
A list of t ()) 213 is defined.

In the system development using the object-oriented technology, the client interface class 11
0, a client class 120 is generated, and in the generated client class 120, specific processing contents of the methods 111 and 112 described above are defined. Similarly, a server class 220 is generated by inheriting the client interface class 210, and specific processing contents of the above-described methods 211, 212, and 213 are defined in the generated server class 220. Note that both the generated client class 120 and server class 220 generate objects (client object and server object) that are instances when the system is executed, and perform processing by communicating with each other.

Further, an assistant server class 320 is generated by inheriting both the client interface class 110 and the server interface class 210, and the generated methods 111, 112, 211, and 21 are used in the generated assistant server class 320.
2 and 213 are defined. In such an assistant server class 320, for example, among methods implemented in the assistant server 301, methods such as information and messages between the client and the server include filtering such as access control and client authentication. It is advisable to describe the processing.
(Frank Buschmann, Regine Meunier, Hans Rohnert, P
eter Sommerlad, and Michael Stal.A System of Patt
erns-Pattern-Oriented Software Architecture-: J
Ohn Wiley and Sons, 1996.)). Also, of the methods implemented in the assistant server 301, one client 101
In a method for sending information, a message, or the like to the client 1, a process for calling a method of another client 101 may be described.

In FIG. 4, reference numeral 400 denotes a property in which information such as a method of starting the client 101, screen settings, and an access destination (access target) required when the system is executed is described. It is read by each client 101. Each client 101 is activated based on the activation method, screen setting, and the like described in the property 400, and accesses the access target (server or assistant server) described in the property 400.

Here, assuming that the assistant server 301 is set as an access destination of the client 101, each client 101 refers to the server interface 303 of the assistant server 301 (information indicating an object to be a communication partner in the memory space). , The assistant server 301 is recognized as a server interface type. Similarly, the assistant server 301 recognizes the server 201 as a server interface type by having a reference to the server interface 202 of the server 201. Accordingly, each client 101 accesses the assistant server 301 via the server interface 303, and further, the assistant server 301
2, the server 201 can be accessed.

Each client 101 has a server 2
Since monitoring information relating to a change in the state of each vehicle 15 is sent from 01, each client 101 needs to be registered as an observer of the server 201. Therefore, each client 101 calls a method for registering as an observer with the assistant server 301, and registers itself as an observer of the assistant server 301. Further, the assistant server 301 is the server 201
Call a method for registering as an observer to the server 201, and register itself as an observer of the server 201. Thereby, each client 101 can receive monitoring information regarding a change in the state of each vehicle 15 from the assistant server 301, and
1 can receive the monitoring information on the state change of each vehicle 15 from the server 201. For this reason,
When a state change of each vehicle 15 occurs, the server 20
1 to the assistant server 301 registered as an observer in the server 201 itself, the monitoring information on the state change is sent.
Then, the monitoring information regarding the state change is sent to the client 101 registered as an observer in the assistant server 301 itself.

Next, the operation of the monitoring control system having such a configuration will be described with reference to FIGS.

First, when the system is started, the client class 120, the server class 220, and the assistant server class 320 are initialized, and the client 101, the server 201, and the assistant server 301 are generated as objects. When the objects of the client 101, the server 201, and the assistant server 301 are generated in this way, each client 101 secures an access method to the assistant server 301 via the server interface 303, and the server 201 Interface 30
2 to secure a method of accessing the assistant server 301. In addition, the assistant server 301 determines the access method to each client 101 via the client interface 102 and the server interface 2
02 and a method of accessing the server 201 via the server 02.

Here, in the supervisory control system operating on the hardware environment shown in FIGS. 1 and 2, each supervisory control message for each vehicle 15 and each supervisory information for changing the state of each vehicle 15 are exchanged. In addition to the communication between the client 101 and the server 201, the communication is also performed between the clients 101 to change the screen settings and the like of the other clients 101. Hereinafter, the operation of the monitoring control system will be described separately for client / server communication and client / client communication.

(Client / Server Communication) First, as the client / server communication, the client 101
It is assumed that a monitoring control message (for example, the startWalking () method) is called from. In this case, since the communication from the client 101 to the server 201 is relayed by the assistant server 301, the client 10
The startWalking () method of the assistant server 301 is called from 1 and an appropriate filtering process is performed in the startWalking () method. After that, the startWalking () method of the server 201 is called from the assistant server 301, and the startWalking (
Processing of alking () method is performed.

Next, it is assumed that a change in the state of the vehicle 15 (for example, a change in the position of the vehicle 15) has occurred from the server 201. In this case, notifyPosition () of the assistant server 301 is called from the server 201, the position information of the vehicle 15 is sent to the assistant server 301, and appropriate filtering processing (for example, selection of a client to be communicated) is performed in the notifyPosition () method. Or exclusion of clients that are not communication targets). Thereafter, the notifyPosition () method of the selected client 101 is called from the assistant server 301, and the position information of the vehicle 15 is sent to the client 101. The client 101 from which the notifyPosition () method is called performs other necessary processing described in the notifyPosition () method, and displays a change in the position of the vehicle 15 via a GUI (Graphical User Interface) or the like.

(Communication between Clients) Next, as communication between clients, it is assumed that a GUI display of one client 101 is changed to a list display of another client 101. In this case, the displayList () method of the assistant server 301 is called from the client 101, and the client name of the transmission destination is passed as an argument. Thereafter, the displayList () method of the client 101 specified by the argument is called from the assistant server 301. Note that the client 101 from which the displayList () method is called performs the processing described in the displayList () method, and changes the GUI display to the list display.

As described above, according to the present embodiment, the assistant server (relay component) 301 relays the communication between each client 101 and the server 201, and independently of the client 201,
Since the communication between the two is relayed, a predetermined filtering process can be performed at the time of communication between the client and the server,
In addition, since it is not necessary for the clients 101 to have a reference to each other, the independence of each client 101 can be improved, and the maintainability and the easiness of change can be improved. Furthermore, since the server 201 is not used for communication between the clients 101, the independence between the client 101 and the server 201 is increased, and the load on the server 201 can be reduced.

According to the present embodiment, the assistant server (relay component) 301 is generated from the assistant server class 320 that inherits both the client interface class 110 and the server interface class 210. 301 can be used as a server from the client 101 and as a client from the server 201.
01 can use the assistant server 301 without changing the application code or the like.

Further, according to the present embodiment, each client 101 can select either the assistant server 301 or the server 201 as an access destination based on the information on the access target described in the property 400. The access target of the client 101 can be switched without changing the code or the like.

In the above embodiment, the objects of the client 101, the server 201, and the assistant server 301 have been described as operating on the hardware environment shown in FIGS. 1 and 2. The operating hardware environment is not limited to this, and it is possible to operate on any other hardware environment.

In the above-described embodiment, the client 101 operates on the terminal 11 and the server 201
Although the description has been made assuming that each object of the assistant server 301 operates on the management computer 12, the operation location of these objects is not limited to this. It may operate on the above.

Further, in the above-described embodiment, each object of the client 101, the server 201 and the assistant server 301 can be described in an object-oriented language such as CORBA as a program having a class configuration as shown in FIG. . The program described in this manner is stored on a floppy disk or CD-ROM (Compact Disk-Read) as a recording medium.
Only on the terminal 11 and the management computer 12, the above-described monitoring and control can be performed.

[0036]

As described above, according to the present invention, the relay component relays communication between each client and the server and relays communication between each client independently of the server. Predetermined filtering processing can be performed at the time of communication between servers, and it is not necessary for each client to have a reference to each other. Therefore, independence of each client can be improved, and maintainability and easiness of change can be improved. further,
Since the server is not used for communication between each client,
The independence between the client and the server is increased, and the load on the server can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a hardware environment in which an embodiment of a client server system according to the present invention operates.

FIG. 2 is a block diagram showing details of a hardware configuration of a terminal and a management computer installed in a central management room shown in FIG. 1;

FIG. 3 is an exemplary view for explaining the configuration and operation of a client server system operating on the hardware environment shown in FIGS. 1 and 2;

FIG. 4 is a diagram showing a class configuration when the client server system shown in FIG. 3 is described in an object-oriented language.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Central control room 11 Terminal 12 Management computer 13 Communication path 14, 16 Transceiver 15 Vehicle 21, 31 Processor 22, 32 Memory 23, 33 Mass storage device 24 Display device 25 Input device 26, 34 Communication device 27, 35 System Bus 100 client process 101 client object 102, 302 client interface 103 client component 110 client interface class 120 client class 200 server process 201 server object 202, 303 server interface 210 server interface class 220 server class 300 assistant server process 301 assistant server object 320 Assistant server class 400 Lopaty

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tohru Takahashi 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture In-house Toshiba Komukai Plant (72) Inventor Nanko Komukai Toshiba, Sai-ku, Kawasaki-shi, Kanagawa Prefecture Town 1 F-term (reference) in Toshiba Komukai Plant 5B098 AA05 AA10 GA04 GC16

Claims (5)

[Claims] 1. A client-server system that performs a predetermined process by linking a client and a server as independent components to each other, comprising: a plurality of clients; a server executing a process requested by each of the clients; A relay component connected to the server, wherein the relay component relays communication between the clients and the server, and relays communication between the clients independently of the server. And a client-server system. 2. The client server system according to claim 1, wherein said relay component performs a predetermined filtering process when relaying communication between each of said clients and said server. 3. The client server system according to claim 1, wherein each of the clients can select one of the relay component and the server as an access destination. 4. The client-server system according to claim 1, wherein said server monitors and controls an object according to a request from each of said clients. 5. A component coordination program for realizing a client-server system for performing predetermined processing by coordinating a client and a server as independent components, wherein the component coordination program described in an object-oriented language is recorded. In a computer-readable recording medium, a client class that inherits a client interface class that abstracts an interface of a plurality of clients, and a server interface class that abstracts an interface of a server that executes a process requested by each of the clients And a relay component class that inherits both the client interface class and the server interface class. Computer readable recording medium recording a component cooperative program characterized.