JP2001125821A - Data communication method and server device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data communication method and a server device by which a client terminal can efficiently acquire hyper text data from an information transmitting server in advance. SOLUTION: At the time of transmitting a request message, a client device designates the kind and hierarchical range of advance acquision information to a server, and the information transmitting server retrieves an information block equivalent to the kind and hierarchical range of the advance acquision information among related information linked with page information in a hyper text format requested by the request message in addition to the page information, and successively transmits them to the client device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication method and a server device in a communication network represented by the Internet, and more particularly, to a data block including link information for accessing another related information block. The present invention relates to a hypertext data communication method and a server device.

[0002]

2. Description of the Related Art In a data communication network based on the Internet Protocol (IP) as a data transfer protocol, that is, the so-called "Internet", an FTP (File Transfer Protocol) which is a protocol for transferring files is used.
Server using HTTP, Hypertext Transfer Protocol (HTTP) that handles multimedia information in which a plurality of types of data such as text, images (graphic data), moving images, and audio are mixed.
Protocol (WWW) server using the Internet is used as a source of information to the world and a source of information. Recently, the spread of digital equipment for general users has made it possible for client terminals to easily handle image data and moving image data. Therefore, content transmitted from a WWW server can also be converted from text-based information.
The information has been changed to hypertext format information including a plurality of types of information (multimedia information) on the same page.

In order to make an information communication system practical, a transfer protocol that is excellent in, for example, an information search function and an update function in addition to simple information acquisition is required. In HTTP, these functions are realized by indicating the purpose of a request by a method. In HTTP, an identifier indicating a resource to which the method is applied: URI (Uniform Resource Identifier)
As a URL (Uniform Resour
ce Locator) or URN (Uniform
Resource Name).

When accessing a WWW server, a client terminal transmits a request message specifying a method, a resource identifier URI (object information name and location), and a version of the HTTP protocol. When acquiring information from the WWW server, the client terminal issues, as a method, a request message describing "GET" meaning information acquisition. For example, "index-j.htm" stored on the server "www.hitachi.co.jp"
When acquiring the information "l", the client terminal transmits the next request message. GET http://www.hitachi.co.jp/index-j.html HTTP / 1.1 The WWW server searches for information in response to the above request message, and the searched information block (page information)
Is returned to the client terminal. In this case, the page information is HTML (Hyper Text
Markup Language), and has a data structure in which arbitrary content in the page is linked to other information blocks by link information. In this specification, HTM
Among the contents described in L, an information block having a data structure associated with another information block by link information is called a “page”, and an isolated information block that does not include link information is called “content”. I will.

[0005]

The client terminal receiving the response message from the server displays the acquired page information on the screen. When the user selects a specific information area on the display screen, a new request message having the link information set in this information area as a URI is generated and transmitted to the server. As a result, a response message including a new information block (page information or content information) corresponding to the URI is transmitted from the server, and is displayed as related information on the display screen of the client terminal.

In the latest version of HTTP / 1.1,
Client side (browser) with TCP connection established between client terminal and WWW server
, Requests are successively issued, and the server side sequentially pipelines these received requests, so that a response can be continuously transmitted. For example, if the browser is instructed to prefetch related information in advance, when the first page information is obtained from the server, the browser analyzes the link information in the received page and automatically issues an addition request. . By storing the service information transmitted from the server in response to these additional requests on the disk of the client terminal, when the user instructs to obtain the related information on the display screen of the first page, the corresponding information is obtained. Is read from the disk, the relevant information can be instantaneously displayed on the screen.

However, according to the prior art, a request for related information from a client terminal has a format in which a request message is issued for each link information. For this reason, when the advance acquisition function of related information by the browser is used, the same number of request messages as link information are issued one after another, and responses are returned from the server one after another in response to each request. When a lot of link information is set on a page, there is a problem that traffic on a network increases rapidly.

[0008] In the Internet used by users all over the world, access from a large number of users across borders concentrates on particularly popular information transmission servers and servers handling information on global events. I do. Therefore, in these popular servers, in addition to the situation where the information transmission capability is reduced due to the concentration of accesses from a large number of users, the occurrence of burst requests from client terminals due to the above-described related information advance acquisition function. However, there is a danger that the capacity of the communication control buffer becomes insufficient, and as a result, a part of the reception request is discarded.

As a method of increasing the processing capacity of the information transmission server, for example, a method of distributing server access by installing a server functioning as a mirror site separately from the server functioning as the original site, and a method of increasing the information transmission server A caching server for temporarily storing information drawn by a user from an information transmission server is provided on an access route to a server, and a request from another user is processed by the caching server. . However, in order to further enrich service information (content) and provide a prompt information service to an unspecified number of clients expected to increase further in the future, it is not sufficient to simply improve the data processing capability on the server side described above. Therefore, it is necessary to improve a data communication method between the server and the client.

An object of the present invention is to provide a data communication method capable of efficiently distributing service information from one information transmission server to a large number of client devices. Another object of the present invention is to provide a server device capable of efficiently providing hypertext data to a client device by effectively using communication resources.

[0011]

To achieve the above object, according to the present invention, service information is stored in a data format including link information for accessing another information block related to one information block. In a data communication method between a server device and a client device connected to the server device via a communication line, (A) specifying an information identifier and an attribute of preceding acquisition information from the client device to the server device (B) the server device searches for an information block having the information identifier specified in the request message, and then links the specified attribute included in the information block. Based on the information, additional search for related information blocks is performed, and the above search results are returned as response messages to the client. And transmits to the winding device.

The attribute of the pre-acquisition information specified in the request message indicates, for example, a plurality of information types to be pre-acquired collectively, and the server device includes the information block having the specified information identifier in the information block. The related information is additionally searched for based on the specific type of link information specified by the attribute among the link information to be related. The attribute of the pre-acquisition information specified in the request message may indicate a hierarchical range related to a specific type of link information. In this case, for the specific type of information, the server sequentially searches the link information up to the stage specified in the hierarchical range, starting from the information block having the specified information identifier, and additionally searches for related information. More specifically, in the present invention, each information block stored by the server device is, for example, HTML (Hyper Text Markup Lang).
uage), and the request message and the response message described above comply with HTTP (Hyper Text Transfer Protocol).

A server device according to the present invention stores service information in a data format including link information for accessing another related information block in one information block, and is connected to a client device via a communication line. For providing an information service in response to a request from the client device, and when receiving a request message specifying the information identifier and the attribute of the pre-acquired information from the client device, the information block having the information identifier is searched. Then, based on link information corresponding to the specified attribute included in the information block, a search unit for additionally searching for a related information block, and transmitting the searched information block to the client device by a response message. And means for performing the above steps. In order to facilitate the additional search of the related information block, for example, the search unit internally generates a request for an additional search using link information as an information identifier, and a request message received from the client device. And means for searching for information in response to the internally generated request.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a communication network system to which the present invention is applied. The communication network system includes a plurality of client terminals 1 (1A, 1A, 1A) connected to an IP (Internet Protocol) network 3.
B,... 1N) and a plurality of information transmission servers, for example, WW
W server 2 (2A to 2M). In an actual system, a part of the client terminal is connected to an access point (gateway device) of an IP network through a public telephone line, for example, and communicates with each server 2 via the access point.

FIG. 2 shows the configuration of the client device 1. The client device 1 includes a processor 10, a network interface 11 connected to a communication line,
A memory (for example, a disk device) 12 for temporarily storing information (page information or content information) obtained from the server 2, a work memory 13 used by the processor, and various programs executed by the processor are stored. Move the cursor on the program memory 14, the display device 15, and the display screen of the display device to display icons,
It comprises a position information input device (mouse) 16 used for selecting operations of menus or contents, a keyboard 17 provided with keys for inputting characters and commands, and a bus 18 for connecting these elements.

An operation system (OS), communication control software 141, WW
In addition to a browser 142 for communicating with the W server and various application programs 145, a request processing routine 143 and a response processing routine 144 described later are stored.

FIG. 3 shows the configuration of the WWW server 2. W
The WW server 2 includes a processor 20, a file device 21 storing various service information (hypertext data) to be provided to the client terminal, and a search for temporarily storing the service information retrieved from the file device 21. Result storage file 22 and program memory 23 for storing various programs executed by the processor
And a work memory 24 on which various tables such as a request table 200 described later are formed, a network interface 25 connected to a communication line, and a bus 26 connecting these elements. The program memory 23 includes an operation system (OS) and communication control software 231, a request reception processing routine 232,
An information search processing routine 233, a search result analysis processing routine 234, and an information transmission processing routine 235 are stored.

FIG. 4 shows the structure of the request table 100 used by the request processing routine 143 of the client device 1. The request table 100 includes a server address 101,
An address 102 of the requested page in the server;
A preceding acquisition information type 103 and a search hierarchy range 104 are defined. For example, when the user enters the server `` www.
page "index-j.htm" held in "hitachi.co.jp"
When “l” is instructed, “www.hitachi.co.jp” is stored as the server address 101 and “index-j.html” is stored as the requested page address 102.

According to the present invention, when a request page is designated on a browser screen, or before a request page is designated,
Information associated with the user by the link information in the request page (related page information or related content information)
Of the information 103 desired to be obtained in advance is designated. In addition, among the related information, particularly for text information, the user is caused to specify a search hierarchy range 104 that indicates the number of steps to follow the link from the request page as a base point to obtain the related information in advance. However, in order not to complicate the information search processing by the server, the specification of the preceding acquired information type and the search hierarchy range is valid only for the related information existing in the same server.

The request processing routine 143 associates the pre-acquired information type 103 specified by the user and the search hierarchy range 104 with the server address 101 and the requested page address 102, as described later, and
0, and instructs the server to acquire related information within the range specified by the preceding acquired information type 103 or the search hierarchy range 104 along with the request message for acquiring the request page. I do.

FIG. 5 shows the structure of the request management table 200 provided in the WWW server 2. Request management table 200
Is the client address 201 and the request page 202
, The type 203 of the preceding acquisition information, and the search hierarchy range 204
And the relationship is defined. When the WWW server 2 receives the request message from the client terminal 1,
As shown in FIG. 6, the request message is accumulated in the request buffer by the request reception processing routine 232. Further, the request management table 200 contains the IP address 2 of the client terminal that has transmitted the request.
The request page 202, the preceding acquisition information type 203, and the search hierarchy range 204 are stored in correspondence with 01.

The information retrieval processing routine 233 sequentially retrieves request messages from the request buffer 240, and retrieves a page (HTML document) corresponding to the request from the service information file 21. The information search processing routine 233 stores the search result in the search result storage file 22 together with the request message, and then notifies the search result processing routine 234 of the search completed request message.

The search result processing routine 234 refers to the request management table 200 based on the request page address of the request message, and searches the search result storage file 22.
It is determined whether or not additional search is necessary for the search results newly stored in. At this time, the page address 202 and the client address 2 indicated by the record corresponding to the request message read from the request management table 200 are stored.
01 is stored in the transmission address table 210.

If the pre-acquired information type 203 of the request management table 200 indicates the pre-acquisition of related information for the retrieved page, the link information included in the page is analyzed and the pre-acquired information type is analyzed. A request message for an additional search is generated for the information link of the type specified in
Add to 0. Further, for each addition request message, a new record indicating the relationship between the client address 201 and a new requested page address searched for in each addition request is added to the request management table 200. Prior acquisition information type 203 of these additional records
Is set to “0” indicating no designation.

When text information is specified as the preceding acquired information type for the page searched this time, it is determined whether or not a hierarchy is specified in the search hierarchy range 204, and if the hierarchy is specified. In the case, the search hierarchy range 20 of each additional record related to the text information
4 is set to a value obtained by subtracting “1” from the current designated value. For the page searched this time, no text information was specified as the type of preceding acquisition information, and the search hierarchy range 2
When the hierarchy is designated in the page 04, a request message for an additional search is generated for the text information link included in the page, and the request buffer 24
0, and for each additional request message,
A new record indicating the relationship between the client address 201 and a new requested page address searched for in each additional request is added to the request management table 200. Also in these additional records, the preceding acquisition information type 203 is set to “0”, and the search hierarchy range 204 is set to a value obtained by subtracting “1” from the current value.

With the addition of the additional search record to the request management table 200 described above, for text information, related information can be searched in a tree structure with each text information link included in the first searched page as a root. Repeated. The search result processing routine 234 deletes the corresponding record from the request management table 200 for the request for which the link information analysis of the search result has been completed.
The request message is notified to the information transmission processing routine 235.

The information transmission processing routine 235 reads a search result corresponding to the request message from the service information file 21 and generates a response message. The response message is incorporated in an IP packet addressed to the client address indicated by the transmission address table 210, and transmitted to the requesting client terminal 1 via the network interface 25.

In the above embodiment, the reason why the application range of the search hierarchy range 104 is limited to text information is to suppress the amount of information to be obtained in advance and to effectively use communication resources. That is, the amount of image and audio data is much larger than text data even when the information is compressed, and if the prior acquisition of such information is permitted in a specified hierarchical range, traffic increases, This is because it is necessary to prepare a large-capacity buffer memory on the client device side, and not all the information obtained in advance is referred to by the user.

FIG. 7 schematically shows the data structure of the hypertext data stored in the service information file 2 provided in the information transmission server 2. Here, as described above, among information blocks described in a hypertext format such as HTML, an information block having a link structure that can be expanded into related information is defined as a “page”, and expanded into related information. A single information block without a symbol, eg, jp
Image data in eg or gif format, moving image data in mpeg or avi format, executable files represented by the Java language, and the like are defined as “content”.

As shown in the data block 210, the page A is composed of pages A1, A2, A3, α, β and contents C1, C2, γ. The information blocks serving as the components of each page, for example, the pages A1, A2, A3, α, β and the contents C1, C2, γ constituting the page A do not always exist in the same server. . Here, it is assumed that the pages A1, A2, A3 and the contents C1, C2 exist on the information transmitting server 2, and the pages α, β and the contents γ exist on another server. Data block 210 of page A
Contains link information to pages A1, A2, A3, α, and β. The linked pages A1, A2, and A3 are, as shown in data blocks 211, 212, and 213, lower-order pages A11 to A31, respectively. And content C11-
consists of α1.

The pages A, A1 to A3, A11 to A3
1, the entities of the contents C1 to C311 may be directly embedded in the page to which they belong, or may be data obtained by storing the contents in a storage area different from the belonging page and linking the contents to the belonging page by link information. It may be a structure. When the content information is text, the former structure can be applied. However, the latter structure is suitable for content information such as images, sounds, and moving images. Here, page A1, which is a component of page A, is text information, page A2.
And A3 are image information, and pages α and β are audio information.

In the present invention, when the user designates a text and an image as the type 103 of the preceding acquisition information when acquiring the page A, in addition to the data block 210 defining the target page A, Among the information blocks of the type specified in the preceding acquisition information type in the information transmission server 2, that is, the page A
1 data block 211 and page A including image information
2. Data blocks 212 and 213 of A3 are additionally searched and transmitted to the client terminal. Also, if the user
For example, when the hierarchy “2” is designated as the search hierarchy range 104, the data blocks 211 of the first hierarchy page A1 including the text information among the components of the target page A
And second-level pages A11 and A1 constituting the page A1
2 including text information, for example, page A
Eleven data blocks 216 are additionally searched and transmitted to the client terminal by a response message.

FIG. 8 shows the display device 15 of the client terminal.
1 shows an example of the page screen 150 output to the user. The above page is, for example, "http // www.hitachi.co.jp / index-j.ht
"HITACHI" 151 and a product introduction column 153.
And a topics column 155. A plurality of images (image 1, image 2,...) 153A, 153B,. Is done. One of the heading character strings is, for example, “about a new management system ”. Each heading character string is underlined at a part, which means that related information is linked to this part. When the user selects the underlined portion by operating the mouse, information related to the selected character string is displayed on the screen as new page information.

FIG. 9 shows an HTML document structure corresponding to the page contents shown in FIG. HTML documents are symbols
The tag indicated by <> is a component, and one HTML
The document starts with <HTML> and ends with </ HTML>. Each HTM
The L document includes an entity header part described between <HEAD> and </ HEAD>, and an entity body part described between <BODY> and </ BODY>. Title 151 is <TITLE
> And </ TITLE>.

In FIG. 9, “IMG” shown in step 1000
SCR = "images / top / 1_1.gif" is the image "1_1.gif" that exists in the directory "images / top /" on the server.
Is displayed in the image area 153A of FIG. 8 defined between <TD and </ TD>. Similarly,
Step 1001 means displaying the image “1_2.gif” existing in the directory “images / top /” in the image area 153B of FIG. 8 defined between <TD and </ TD>. are doing. Step 1002 shows a tag corresponding to the topic headline character string “new management system ” in FIG. Where "<A HREF =" / topics /
9904 / 01a.html "> Management structure </A>" indicates link information attached to the character string "Management structure". When the user selects the character string "Management structure" on the display screen, the server " www.hitachi.co.jp "existing address" / topi
cs / 9904 / 01a.html "is displayed on the screen.

FIG. 10 shows a client terminal 1 and a server 2
1 shows a conventional communication procedure of hypertext data executed at the IP level. Prior to requesting page information from the server 2, the client terminal 1 first executes a procedure for opening (establishing) a TCP connection between the client terminal and the server (step 310). H
After the TTP version "HTTP / 1.1", the TCP
Once the connection is established, the TCP connection will remain in place to allow pipeline communication, unless either the client or server indicates disconnection.

When the TCP connection is opened,
An HTTP request is transmitted from the client terminal (Step 320). As described above, the HTTP request is "G" which means an information acquisition request as a method.
ET "and specify the application target of the request, for example," index-j.html "held by the server" www.hitachi.co.jp "with the resource identifier URI (object information name and location), and A request message (Request 1) specifying the version is transmitted. Upon receiving the request message, the server 2 receives the resource identifier UR
After searching for the requested page information specified by I, a response message (Response 1) including the search result is returned to the client terminal (step 340).

The response message includes a status line and a message body following the status line. The status line includes an HTTP version, a three-digit number status code indicating the processing result of the request, and a reason statement that describes the status code in text.
When the request is processed normally, for example, “HTTP / 1.1 200 OK” is returned as the status line. The message body of the response message is composed of an HTTP header indicating the processing date and time of the request, the server name, the type, length, encoding format, and the last update date of the content to be transmitted, and the entity body. http // www.hitachi.co.jp "/ in
When “dex-j.html” is requested, an HTML document having the contents shown in FIG. 9 is transmitted to the client terminal as the entity body of the response message.

In the conventional communication procedure, when the user previously specifies the type of the preceding acquisition information, the client terminal 1
Is H when a response message is received from the server.
Analyzes the TML document, finds the specified type from the related information defined in the link information in the received HTML document, and requests the server to transmit the information (step 3).
30). The above request is performed by transmitting a separate request message (Request 2, Request 3,...) For each link information, and the server 2 executes a search process corresponding to each of the request messages, and obtains the respective search results. To the response message (Response 2, Response 3,…)
(Step 350).

FIG. 11 shows a communication procedure according to the present invention executed between the client terminal 1 and the server 2 in order to obtain hypertext page information. In the present invention, after opening the TCP connection (step 310), when requesting target page information, the client terminal 1 specifies the type 103 of the pre-acquired information and the search hierarchy range 104 (step 321). The additional information is transmitted to the server in the first request message (Request 1).

The specification of the preceding acquisition information type 103 and the search hierarchy range 104 is, for example, as shown in FIG.
03A, "image / jpeg" 103B, "image / gif" 10
3C, including “audio / midi” 103D, search hierarchy range 1
04, “Tier 0” 104A, “Tier 1”
A selection menu screen including 104B and “tier 2” 104C may be displayed, and the server may notify the server of options specified by the user. Here, “jpeg”, “gif”, and “midi” indicate types of image and audio coding methods.

When the user enters "text / h
If "tml", "image / jpeg", or "image / gif" is specified, a new statement that means a request to acquire multiple media types, for example, Allget-mediatype = text / html, image / jpeg, image / gi
Add f to the request message. When the user specifies level “1” as the search hierarchy range, for example, hierarchy = 1 is added to the request message as a statement indicating the search hierarchy range of the text information (text / html).

The server 2 determines the type of the preceding acquisition information 10
When the request message including the statement No. 3 and the specification statement of the search hierarchy range 104 is received, as described with reference to FIG. 6, the page information specified by the request message is searched (step 340), and then the link included in the search page is searched. The information is analyzed, and the type 103 and the search hierarchy range 10 of the preceding acquisition information specified in the request message are analyzed.
Additional search for related information corresponding to No. 4 (step 34)
Execute 1). After these search results are stored in the search result storage file 22, the information transmission processing routine 23
4, the response message is incorporated into the response message and transmitted to the requesting client device (step 36).
0). In this case, for example, the retrieved page information (HT
For each ML document), a response message including the status line described above and a message body following the status line is generated, and one page of HTML is included in each message body.
The transmission of the response message is repeated with the document set (step 361). However, if the data amount is small, a plurality of response messages may be collectively transmitted in one IP packet.

In HTTP, RFC 1341, 1521, 159
0, etc., MIME (Multipurpose Internet Mail Exten
sions), the type of media received from the client terminal to the server can be specified. For example, to obtain text information described in HTML, by specifying "Accept: text / html",
The format of the received information can be limited. Other types include "multipart", "image", "application", and "aud".
"io", "message", and "video" can be specified. However, the Accept statement is, as in the present invention, used to specify a specific information type to be pre-acquired by additional search among the related information linked to the request page information specified by the URI of the request message. Rather, it is functionally distinct from Allget-mediatype described above.

In FIG. 12, the type of the preceding acquisition information 10
3 is displayed by an option combining the information type and the encoding method. However, in consideration of the fact that the application can specify the extension, simply use “html”, “jpg, jpeg”,
It may be specified by options such as “gif” and “mid”. In the embodiment, the information search processing routine 133 is executed.
The link information to be additionally searched is specified by analyzing the search result (HTML document) by the search result analysis processing routine 234. However, in order to facilitate the analysis processing, the server side stores the link information in the service information file 22. A list of link information (address and information type) serving as a component is stored in a separate file in advance corresponding to each registered page information, and when a search result is obtained, the above-mentioned separate file is referred to. Alternatively, the link information corresponding to the preceding acquisition information designated by the client may be specified.

[0046]

As is apparent from the above description of the embodiment, according to the present invention, when the client device pre-acquires the request information, the number of events of the information acquisition request to the information transmission server can be reduced. Even when access from a large number of users is concentrated on the transmission server, the possibility that the request message is rejected due to event competition can be reduced. Further, in the present invention, based on one request message received from the client device, an additional search is automatically executed on the information transmission server side, and the obtained search results are sequentially returned to the client device. Therefore, the pre-acquisition information can be delivered to the client by effectively using the resources of the communication network.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a communication network system to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration of a client device 1 in FIG.

FIG. 3 is a block diagram showing a configuration of an information transmission server 2 in FIG. 1;

FIG. 4 is a request table 1 used by the client device 1
FIG.

FIG. 5 is a diagram showing a configuration of a request management table 200 used by the information transmission server 2.

FIG. 6 is a diagram for explaining the operation of a processing routine executed by the information transmission server 2.

FIG. 7 is a diagram for explaining a data structure stored in a service information file 21 provided in the information transmission server 2.

FIG. 8 is a view showing an example of a page screen displayed on the client terminal 1.

FIG. 9 is a view showing a main part of an HTML document structure corresponding to the page screen of FIG. 8;

FIG. 10 shows a conventional communication procedure of hypertext data executed between a client terminal 1 and a server 2 by IP.
FIG.

FIG. 11 is a diagram showing, at an IP level, a communication procedure of hypertext data executed between the client terminal 1 and the server 2 according to the present invention.

FIG. 12 is a diagram showing an example of a menu screen for specifying a pre-acquired information type and a search hierarchy range.

[Explanation of symbols]

1. Client device 2. Information transmission server 3. IP
Network, 10 processor, 11 network interface, 12 disk storage device, 13 work memory, 14 program memory, 15 display device,
100 request table, 141 OS / communication control software, 142 browser, 143 request processing routine, 1
44: Response processing routine, 145: Application program, 20: Processor, 21: Service information file, 22: Search result storage file, 23: Program memory, 24: Work memory, 25: Network interface, 200: Request management table, 210 ... Sending address table, 231 ... OS / communication control software, 2
32 ... request reception processing routine, 233 ... information search processing routine, 234 ... search result analysis processing routine, 235 ...
Information transmission processing routine.

Continued on the front page (72) Inventor Yasuo Murakami 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Communication Systems Division of Hitachi, Ltd. (72) Inventor Daisuke Okabe 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in Hitachi, Ltd. Communication Systems Division (Reference) 5B075 ND36 PQ05 5B082 FA03 5B089 GA11 GA21 GB04 HA10 JA24 JB22 KA04 KB07 KC44 LB14

Claims (6)

[Claims] 1. A server device storing service information in a data format including link information for accessing another information block related to one information block, and a server device connected to the server device via a communication line. In a data communication method with a client device, a request message is transmitted from the client device to the server device in a form in which an information identifier and an attribute of preceding acquisition information are specified, and the server device specifies the request message in the request message. After searching for the information block having the specified information identifier, the related information block is additionally searched based on the link information corresponding to the specified attribute included in the information block, and the respective search results are described by a response message. A data communication method for transmitting to a client device. 2. The method according to claim 1, wherein the attribute of the pre-acquisition information specified in the request message indicates a plurality of information types to be pre-acquired, and the server device transmits the link information included in the information block having the specified information identifier. 2. The data communication method according to claim 1, wherein related information is additionally searched based on the specific type of link information specified by the attribute. 3. An information block having an attribute of the preceding acquisition information specified in the request message indicating a hierarchical range of link information of a specific type, and the server apparatus having the specified information identifier for the information of the specific type. 2. The data communication method according to claim 1, wherein the link information is sequentially traced to a stage designated in the hierarchical range, and related information is additionally searched. 4. Each of the information blocks is an HTML (Hyper)
The request message and the response message have a hypertext format described in Text Markup Language (HTTP), and the request message and the response message are HTTP (Hyper Text Transfer Protocol).
The data communication method according to any one of claims 1 to 3, wherein the data communication method follows l). 5. Service information is stored in a data format including link information for accessing another information block related to one information block, and responds to a request from a client device connected via a communication line. When a request message that specifies the information identifier and the attribute of the preceding acquisition information is received from the client device,
Search means for searching for an information block having the information identifier, and additionally searching for a related information block based on link information corresponding to the specified attribute included in the information block; And a means for transmitting a response message to the client device by a response message. 6. A means for internally generating a request for an additional search using the link information as an information identifier, a request message received from the client device, and the internally generated request message. 6. The server device according to claim 5, comprising means for searching for information in response to the request.