JPH09218816A - File transfer method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discontinue the transfer of plural documents from a server to a client and to efficiently limit the transfer of the plural documents. SOLUTION: For the file request of one time issued by the instruction of a user or a program in a document requesting device 120, plural file transfer requests are successively trinsmitted to a document providing device 110 and thus, the transfer of plural files to the document requesting device 120 is started. During the transfer of the plural files, when it is judged that predetermined transfer discontinuing conditions are established by a transferred total data size, file transfer time or the presence/absence of the issuance of an interruption instruction, the transmission of all non-transmitted file transfer requests to be transmitted following the file transfer request transmitted latest is interrupted and thus, the transfer of the plural files is discontinued at the point of time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file transfer method used in a client / server system including a server which provides a service for providing files and a client which requests a file transfer from the server.

[0002]

2. Description of the Related Art As a document providing program for providing a file such as a document from a server to a client via the Internet, WWW (World Wide Wide)
Web) is known. This is a WWW server and WW
It consists of a W client, and the file transfer protocol HTTP (H
hyper Text Transfer Protocol
ol), files such as documents are provided from the server to the client.

In this method, it is basically necessary to transfer the document file from the server to the client one by one. That is, when the user requests the display of a file such as a document,
The WWW client communicates with the WWW server to transfer the document and display it on the screen. When another document is to be displayed, this operation is performed again.

However, this method is not sufficient when using a computer, such as a portable information terminal, which is not always used in an environment where network connection is possible, as a client computer. In order to immediately provide the user with the necessary documents in response to the user's request,
When the client computer is connected to the network, it is necessary to collectively transfer multiple documents from the server to the client and store them on the client side.

[0005]

As a method for realizing this, not only the document requested by the user to be transferred, but also
A method of collectively transferring related documents from a server to a client has been proposed by the present applicant (Fujii et al., “Document requesting method, document providing apparatus, document requesting apparatus and document transferring method” Japanese Patent Application No. 7-292910). .

By utilizing this method, a plurality of documents can be transferred from the server to the client by a single instruction without the user having to instruct each one. The transferred document is stored in the storage medium of the client. Specifically, a program for sequentially transferring a plurality of documents in response to a single transfer request of a user is started and stored in a storage medium of a client, or a plurality of documents are linked in advance and combined into one document, It describes a method of storing this linked document in the storage medium of the client. However, this method may cause problems in the following cases.

That is, when the data amount of the related document with respect to the document requested from the client to the server is large, it takes a long time to complete the transfer of all the documents, which causes a problem such as an increase in network traffic. cause. In addition, when many documents are transferred when the free space of the storage medium of the client is not large enough, it may occupy most of the file system of the client. Further, in the case of the method of connecting a plurality of documents and transferring them as one document, when the transfer of the documents is interrupted at the request of the user, the documents which have been transferred by that time cannot be utilized. There is also a problem called.

Further, it is conceivable that these documents may be transferred even if the client is not capable of displaying a still image or a moving image, or is not capable of reproducing voice. Transferring a document that cannot be used by the client wastes the storage medium of the client and leads to meaningless increase in network traffic.

The present invention has been made in view of the above point, and is performed when the document transfer is not high speed, the free space of the storage medium owned by the client is small, or the document display / reproduction capability of the client. An object of the present invention is to provide a file transfer method that can efficiently restrict the transfer of multiple documents, and that can be used on the client side for already transferred documents even if the file transfer is aborted midway due to the restriction. To do.

[0010]

According to the present invention, there is provided a client / server including a server which provides a service for providing a file and a client which requests a file transfer from the server.
In a file transfer method used in a server system, a plurality of files including a file designated by a file request issued by the client and a file related to the file request issued by the client are sent from the server to the client. In response to the one-time file request, a plurality of file transfer requests are sequentially transmitted to the server, and when it is determined that a predetermined transfer abort condition is satisfied, the file should be transmitted after that. The feature is that transmission of all file transfer requests is stopped.

In this file transfer method, a plurality of file transfer requests are sequentially transmitted to the server in response to one file request issued by the client under the instruction of the user or the program, whereby a plurality of file transfer requests from the server to the client are sent. File transfer starts. During the transfer of the plurality of files, if it is determined that a predetermined transfer abort condition is satisfied, for example, depending on the total data size transferred from the server to the client, the file transfer time, or whether or not an interrupt instruction is issued, Transmission of all remaining file transfer requests to be transmitted thereafter is stopped, whereby the multiple file transfer is terminated at that time. Therefore, it becomes possible to efficiently restrict the transfer of multiple files, the storage medium capacity is small, and a system that uses a personal digital assistant as a client-side computer that is not always used in an environment in which a network connection is possible It is possible to realize a file transfer suitable for the above.

Further, when a plurality of files are transferred from the server to the client using the concatenated file, even if the transfer of the concatenated file is interrupted midway, the contents of the transferred file can be utilized on the client side. In order to achieve this, it is preferable to transfer a concatenated file, which is a concatenation of a plurality of compressed files compressed in file units, from the server to the client in response to a single file request issued by the client. As a result, for example, even when the transfer abortion of a concatenated file is aborted in the middle due to a predetermined transfer abortion condition being satisfied by the total data size transferred from the server to the client or the file transfer time, etc. Each compressed file that has been transferred to the client can be restored in file units.

It is also possible to use a method of transferring a concatenated file in which a plurality of files are concatenated so that the file designated by the file request issued by the client is at the head from the server to the client.
In this case, since the file requested by the user is first transferred to the client, even if the transfer abort condition is met and transfer of the concatenated file is aborted midway, at least at that time There is a high probability that it is completed and you can use it.

Further, the present invention provides a file transfer method used in a client / server system including a server which provides a service for providing a file and a client which requests a file transfer from the server. Of a plurality of files including a file designated by the file request of 1 and a file related to the file request such as a still image, a moving image, a sound, and the display reproduction capability of the client. A file that matches the condition is selected, a file transfer request that specifies it for each selected file is transmitted to the server, and only the file that matches the transfer condition among the plurality of files is transmitted from the server. It is characterized in that it is sent to the client.

In this file transfer method, only the files selected according to the type of file such as still image, moving image, audio, etc. and the display / playback capability of the client can be transferred from the server to the client and used by the client. It is possible to prevent the waste of the storage medium of the client due to the transfer of the unreadable file and the meaningless increase of the network traffic.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an information communication system to which a file reading method according to an embodiment of the present invention is applied and a functional configuration of a program used in the system. This information communication system is, for example, a client / server system that provides various document files (Hypertext in HTML format, still images, moving images, audio, etc.) from a server to a client using a network environment such as the Internet. Document providing device 1 that operates as a WWW server that provides files
10 and a document request device 120 that operates as a WWW client that requests a document file.

In the document providing apparatus 110, the document providing program 150 operates. This document providing program 150
Serves as a WWW server program, and as shown in the figure, the request receiving unit 151 and the request processing unit 15
Consists of two. The request receiving unit 151 is a program that receives a document file transfer request or the like according to a file transfer protocol such as HTTP from the document display program 130 operating in the document providing apparatus 120. Request processing unit 152
Is a program that performs specific processing in response to a request received by the request receiving unit. For example, when the request receiving unit 151 receives the above-mentioned document file transfer request 140, the corresponding document file 111 is searched from the storage medium 156, and when the corresponding document is found, the document file transfer 141
I do.

In the document request device 120, the document display program 130 operates. This document display program 130
Operates as a WWW client program (WWW browser), and as shown in FIG.
1, a document requesting unit 132, a document receiving unit 133, a document storage unit 134, a document display unit 135, a request receiving unit 136, a connection releasing unit 137, and a plural document transfer requesting unit 138.

The connection unit 131 is a program for connecting to the document providing apparatus 110 using a protocol such as TCP / IP. The document request unit 132 is a program that issues the above-mentioned document file transfer request to the document providing apparatus 110 using a file transfer protocol such as HTTP. The document receiving unit 133 is a program that receives a document file provided from the document providing apparatus 110.

The document storage unit 134 is a program for caching (temporarily storing) the document file received from the document providing apparatus 110 in the local file cache area 121a of the storage medium 121. The document file cached in the local file cache area 121a is automatically assigned a name unlike a normal file which is explicitly designated and saved by the user, and is saved regardless of the user's instruction. It The storage position of the document file cached in the local file cache area 121a and its file name are independently managed by the document display program 130.

This local file cache area 12
The reference numeral 1a is used to reduce network congestion, and the local file cache area 121
When a display request for the document file stored in a is issued by the user or the like, basically, the document providing apparatus 110 is not accessed, and the corresponding document file is read from the local file cache area 121a. Issued and displayed on the screen. Further, the document requesting device 120 notifies the document providing device 110 of the creation date and time of the cached document file, inquires whether the document file is the latest file, and when the content of the corresponding document file is updated. Document providing device 1
An operation mode in which the updated document file is transferred from 10 to the document requesting device 120 can also be adopted.

The document display unit 135 is a program for displaying the requested document file on the screen. Request acceptance unit 136
Is a program which receives a document file transfer request or a document file display request from a user or a program. The connection release unit 137 is a program that releases the connection to the network.

The plural document transfer requesting unit 138 is the request receiving unit 1.
36 is a program for instructing the document request unit 132 to issue a plurality of file transfer requests for one transfer request received. As a result, a plurality of document files including the requested document file and the related document files can be transferred from the document providing apparatus 110 to the document requesting apparatus 120 at once by a single file transfer request operation by the user or the like. it can. In this case, only the document file designated by the file transfer request operation by the user is displayed on the screen, and other related document files are saved in the local file cache area 121a together with the document file designated by the file transfer request operation. .

Acquisition of related file information necessary for issuing a file request such as the location of the related file and its file name can be performed by using one of the following two methods.

(Method 1) From the HTML format document file transferred from the document providing apparatus 110 to the document requesting apparatus 110, link information to a related file embedded therein is extracted to create a document list. To do. And
The document file requests for the related files are sequentially issued while taking out the document files one by one from the document list.

(Method 2) A document list is prepared in advance on the document providing device 110 side for each document file, and the document list corresponding to the document file designated by the document file transfer request from the document requesting device 120 is provided. Transfer from the device 110 to the document requesting device 120. Then, while taking out the document files one by one from the document list, the document file requests for the related files are sequentially issued.

In this way, the plural document transfer request unit 1 which performs the procedure of sequentially transmitting the plural document file transfer requests
38 is not necessarily prepared on the document requesting device 120 side, and a program corresponding thereto may be transferred from the document providing device 110 to the document requesting device 120 together with a document list of related files.

In the transfer of a plurality of document files, a plurality of document transfer requests are not issued, but a plurality of related document files are linked in advance in the document providing apparatus 110, and the linked files are sent to the document requesting apparatus. It can also be realized by a method of transferring to the document providing apparatus 110 in response to a file transfer request from 120 (method 3). In this method 3, the plural document transfer request unit 138 is not particularly necessary.

Next, referring to the flow chart of FIG.
A specific operation procedure of the document display program 130 will be described. First, a user or a program issues a file transfer request to transfer and display a document (step S11). This is U, which is an identifier that uniquely specifies a document
RL (Uniform Resource Locat)
or) should be used. For example, http: // isl. r
dc. toshiba. co. jp / index. ht
If you specify like ml, the transfer protocol is HTTP,
The server, that is, the connection destination document providing device name is isl. rd
c. toshiba. co. jp, file name is ind
ex. It is uniquely specified that the document is specified by html. Hereinafter, the identifier will be described as A.

Next, the request receiving unit 136 receives the display request (step S12), and the document requesting unit 132 sends the document A.
The file transfer request is transmitted to the document providing program 150 in the HTTP format (step S13). The document providing program 150 transfers the document A designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. In this case, if the document providing apparatus 110 holds the document list corresponding to the document A specified by the file transfer request, the document list is transferred to the document requesting apparatus 110 alone or together with the document A. Here, it is assumed that the document list is transferred alone.

Therefore, there are two types of files received by the document receiving section 133. A document list and a general document that is not (document A here). An example of the document list is shown in FIG.

In FIG. 3, <LIST> is a keyword indicating that this file is a document list. The following string indicates the identifier of document A requested by the user. The second and subsequent lines are the identifiers of the respective document files related to this document A. here,. The document file whose name ends with HTML is an HTML document ,. The document file whose name ends with "gif" is a still image document ,. It indicates that the document file whose name ends with au is a voice document.

The document receiving unit 133 uses the keyword of the received file to determine whether the file is a document list (step S14). If it is not a document list, it is a normal document A, so this is displayed and stored in the local file cache area 121a (step S15). Then, the identifier of the related document is extracted from the document A, and the document list is created (step S16). After this, steps S17 to S21
In step S3, a multiple document request transmission process for sequentially issuing document file requests for related files while taking out the document file identifiers one by one from the created document list is started. Even when the file received by the document receiving unit 133 is the document list, the multiple document request transmission process of steps S17 to S21 is similarly performed using the received document list.

In the multiple document request transmission process, first, the multiple document request section 138 determines whether or not the transfer abort condition is satisfied (step S17). The transfer termination condition is for limiting the amount of use of the storage medium 121 of the document requesting device 120 and the communication time through the network, and the total data size of the files transferred from the document providing device 110 is a predetermined value. When the file transfer time exceeds a preset value, or when an explicit transfer stop request (interrupt) is received from the user or program, it is determined that the transfer abort condition has been met. It is preferable.

Specifically, when it is desired to receive only the data having a size equal to or less than a certain amount, the amount of data received by the document receiving unit 133 may be measured, and when the certain value is reached, the process may be terminated. Alternatively, when it is desired to keep the size of the free space of the storage medium 121 at a constant value, for example, the upper limit of the receivable data size is determined from the current free space, and the document receiving unit 133 is determined.
When the amount of data received at reaches the upper limit value, it may be terminated. Alternatively, if it is determined that the transfer abort condition is satisfied after a certain time has elapsed after the file transfer was requested, a timer is set so that an interrupt is generated after a certain time has elapsed after the transfer request was sent, and the interrupt is set. You can abort the transfer at the time of receiving. The received data amount may be detected using the data size information added to the document file transferred from the document providing apparatus 110.

When the transfer termination condition is not satisfied, the plural document transfer requesting unit 138 selects one untransferred document from the documents listed in the document list and assigns the identifier to the document requesting unit 132. It is passed to instruct the issuance of the document file transfer request (step S18). When the requested document file is selected in this way, the document request unit 132
Sends a file transfer request for the instructed document in the HTTP format to the document providing program 150 (step S
19, S20). The document providing program 150 transfers the document file designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. This document file is received by the document receiving unit 133 and stored in the local file cache area 121a (step S2).
1). If the file received in step S13 is the document list, the document first received in step S21 is document A, and in that case, the document A screen is also displayed.

The processes of steps S17 to S21 are repeatedly executed until there are no untransferred documents among the documents listed in the document list, and it is determined whether or not the transfer abort condition is satisfied each time one document transfer is performed. To be done. When the transfer termination condition is satisfied (YES in step S17),
The multiple document request transmission process is ended, and transmission of all file transfer requests corresponding to the remaining untransferred documents is stopped.

As described above, according to the file transfer method performed according to the procedure of FIG. 2, the transfer processing of a plurality of documents is terminated when the transfer abort condition is satisfied. Therefore,
The transfer of a plurality of document files can be efficiently restricted, and in particular, a portable information terminal or the like which has a small storage medium capacity and is not always used in an environment in which a network can be connected is used as the document requesting device 120. The file transfer suitable for the system can be realized.

Next, referring to the flowchart of FIG.
A second example of a specific operation procedure of the document display program 130 will be described. This processing procedure is based on the multiple document transfer request unit 1
38 is an example in which 38 is not prepared in the document requesting device 120 from the beginning, but the program is transferred from the document providing device 110 to the document requesting device 120.

First, the user or the program issues a file transfer request to request the transfer and display of the document (step S31). For this, the above-mentioned URL which is an identifier for uniquely specifying a document may be used. For example, htt
p: // isl. rdc. toshiba. co. jp /
index. If it is specified as html, the transfer protocol is HTTP, the server, that is, the connection destination document providing apparatus name is isl. rdc. toshiba. co. jp, the file name is index. It is uniquely specified that the document is specified by html. Hereinafter, the identifier will be described as A.

Next, the request receiving unit 136 receives the display request (step S32), and the document requesting unit 132 sends the document A.
The file transfer request is transmitted to the document providing program 150 in the HTTP format (step S33). The document providing program 150 transfers the document A designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. In this case, if the document providing apparatus 110 holds the document list corresponding to the document A specified by the file transfer request, the document list is transferred to the document requesting apparatus 110 alone or together with the document A. In addition, document A
If the document has a multiple document transfer program that realizes a function of transferring a plurality of documents, the document requesting device 11
Transfer to 0.

Therefore, there are three types of files received by the document receiving section 133. A document having a multiple document transfer program that realizes the function of transferring multiple documents;
Document list and general documents. FIG. 5 shows an example of a document file having a multiple document transfer program. In the document file 900, a program name 901 and a document list name 910 are described. The program performs a procedure for reading the document list and sequentially requesting the document providing apparatus 110 to transfer the document, and is included in the document file 900 together with the document A.

The document receiving section 133 determines the type of the received file (steps S34 and S35). If it is a document list, since the document requesting device 120 does not have a multiple document transfer function, an error is displayed and the process ends (step S3
6). Even when the document is a normal document (document A), the multiple document transfer request process is not performed, the received document A is displayed, and the received document A is displayed in the local file cache area 121.
The data is saved in a and the process ends (step S37).

If the document A includes the plural document transfer program, the control is transferred to the plural document transfer program and the following processing is performed. That is, the plural document transfer program first displays the document A and stores it in the local file cache area 121a, and at the same time, uses the document request unit 132 to request a document list designated by the document list name 902. The document providing device 11
0 (step S38). As a result, the file is transferred from the document providing apparatus 110 and is received by the document receiving unit 133. If the file received by the document receiving unit 133 is not a document list, an error occurs (steps S39 and S36). If it is a document list, the multiple document request transmission process of steps S40 to S44 using the received document list is started under the control of the multiple document transfer program.

In the multiple document request transmission process, first, the multiple document request section 138 determines whether or not the transfer abort condition is satisfied (step S40). The transfer termination condition is for limiting the amount of use of the storage medium 121 of the document requesting device 120 and the communication time through the network, and the total data size of the files transferred from the document providing device 110 is a predetermined value. When the file transfer time exceeds a preset value, or when an explicit transfer stop request (interrupt) is received from the user or program, it is determined that the transfer abort condition is satisfied. It

Specifically, when it is desired to receive only the data of a certain size or less, the amount of data received by the document receiving unit 133 may be measured, and when the value reaches a certain value, the process may be terminated. Alternatively, when it is desired to keep the size of the free space of the storage medium 121 at a constant value, for example, the upper limit of the receivable data size is determined from the current free space, and the document receiving unit 133 is determined.
When the amount of data received at reaches the upper limit value, it may be terminated. Alternatively, if it is determined that the transfer abort condition is satisfied after a certain time has elapsed after the file transfer was requested, a timer is set so that an interrupt is generated after a certain time has elapsed after the transfer request was sent, and the interrupt is set. You can abort the transfer at the time of receiving.

When the transfer termination condition is not satisfied, the plural document transfer program selects one untransferred document from the documents listed in the document list and passes the identifier to the document request unit 132. It issues an instruction to issue a document file transfer request (step S41). When the request target document file is selected in this way, the document request unit 132
A file transfer request for the instructed document is transmitted to the document providing program 150 in the HTTP format (step S4).
2, S43). The document providing program 150 transfers the document file designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. This document file is received by the document receiving unit 133 and stored in the local file cache area 121a (step S4).
4).

The processing of steps S40 to S44 is repeatedly executed until there are no untransferred documents among the documents listed in the document list, and it is determined whether or not the transfer abort condition is satisfied each time one document transfer is performed. To be done. If the transfer termination condition is satisfied (YES in step S40),
The multiple document request transmission process is ended, and transmission of all file transfer requests corresponding to the remaining untransferred documents is stopped.

As described above, according to the file transfer method performed according to the procedure of FIG. 4, the procedure for transferring the related document of the document A by the plural document transfer program transferred together with the document from the document providing apparatus 110 is performed. It is automatically performed, and the transfer processing of a plurality of documents is stopped when the transfer stop condition is satisfied. Therefore, the document requesting device 120
The transfer of a plurality of documents and the control for limiting the transfer can be efficiently performed without preparing a special function in advance.

Next, referring to the flowchart of FIG.
A third example of a specific operation procedure of the document display program 130 will be described. Here, the document transfer is restricted according to the type of medium of the document file and the display / playback function of the document requesting device 120.

First, the user or program issues a file transfer request to transfer and display a document (step S51). For this, the above-mentioned URL which is an identifier for uniquely specifying a document may be used. For example, htt
p: // isl. rdc. toshiba. co. jp /
index. If it is specified as html, the transfer protocol is HTTP, the server, that is, the connection destination document providing apparatus name is isl. rdc. toshiba. co. jp, the file name is index. It is uniquely specified that the document is specified by html. Hereinafter, the identifier will be described as A.

Next, the request receiving unit 136 receives this display request (step S52), and the document requesting unit 132 sends the document A.
The file transfer request is transmitted to the document providing program 150 in the HTTP format (step S53). The document providing program 150 transfers the document A designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. In this case, if the document providing apparatus 110 holds the document list corresponding to the document A specified by the file transfer request, the document list is transferred to the document requesting apparatus 110 alone or together with the document A. Here, it is assumed that the document list is transferred alone.

Therefore, there are two types of files received by the document receiving section 133. A document list and a general document that is not (document A here). The document list is the same as in FIG.

The document receiving unit 133 uses the keyword of the received file to determine whether the file is a document list (step S54). If it is not a document list, it is a normal document A, so this is displayed and stored in the local file cache area 121a (step S55). Then, the identifier of the related document is extracted from the document A, and the document list is created (step S56). After this, steps S57 to S61
In step S3, a multiple document request transmission process for sequentially issuing document file requests for related files while taking out the document file identifiers one by one from the created document list is started. Even when the file received by the document receiving unit 133 is a document list, the multiple document request transmission process of steps S57 to S61 is similarly performed using the received document list.

In this multiple document request transmission process, first, the multiple document transfer requesting unit 138 selects one untransferred document among the documents listed in the document list as the file transfer request target document (step S57). ). When the document file for which the file transfer request is made is selected (step S
58), the plural document request unit 138 determines whether or not the selected document type matches the transfer condition (step S59). The transfer condition is the document requesting device 120.
In consideration of the display / playback function of the document requesting device 120, the document requesting device 120 prevents unnecessary transfer of a document file of a type that cannot be utilized by the document requesting device 120. Is determined in advance according to the display reproduction capability of

For example, if a display that cannot display a moving image is used, the moving image document does not satisfy the transfer condition. If the document requesting device 120 does not have the function of reproducing voice, the voice document does not satisfy the transfer condition.

If the selected document type does not satisfy the transfer condition, steps S57 to S59 are executed again to determine whether another document is selected and the transfer condition is satisfied.

If the selected document type satisfies the transfer condition, the document requesting section 132 sends a file transfer request for the instructed document in the HTTP format to the document providing program 150 (step S60). The document providing program 150 transfers the document file designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. This document file is received by the document receiving unit 133 and stored in the local file cache area 121a (step S61). If the file received in step S61 is a document list, step S61
The first document received in may be document A,
In that case, the screen display of the document A is also performed.

The processes of steps S57 to S61 are repeatedly executed until there are no unselected documents among the documents listed in the document list, and it is determined whether or not the transfer condition is satisfied each time the document is selected.

As described above, according to the file transfer method performed according to the procedure shown in FIG. 6, the document file selected according to the file type such as a still image, a moving image, and a sound and the display / reproduction capability of the document requesting device 120. Only the document requesting device 120 can be transferred from the document providing device 110 to the document requesting device 120, and waste of the storage medium 121 due to transfer of a file that cannot be used by the document requesting device 120, and meaningless increase of network traffic can be prevented. It becomes possible.

Next, referring to the flowchart of FIG.
A fourth example of a specific operation procedure of the document display program 130 will be described. In the previous example, the document requesting device 120 was previously provided with the plural document transfer requesting unit 138 for transferring only the document satisfying the transfer condition. However, this part is not provided here, and the document providing device is not provided. It is transferred from 110.

First, the user or program issues a file transfer request to request the transfer and display of a document (step S71). For this, the above-mentioned URL which is an identifier for uniquely specifying a document may be used. For example, htt
p: // isl. rdc. toshiba. co. jp /
index. If it is specified as html, the transfer protocol is HTTP, the server, that is, the connection destination document providing apparatus name is isl. rdc. toshiba. co. jp, the file name is index. It is uniquely specified that the document is specified by html. Hereinafter, the identifier will be described as A.

Next, the request receiving unit 136 receives the display request (step S72), and the document requesting unit 132 sends the document A.
The file transfer request is transmitted in the HTTP format to the document providing program 150 (step S73). The document providing program 150 transfers the document A designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. In this case, if the document providing apparatus 110 holds the document list corresponding to the document A specified by the file transfer request, the document list is transferred to the document requesting apparatus 110 alone or together with the document A. In addition, document A
If the document has a multiple document transfer program that realizes a function of transferring a plurality of documents, the document requesting device 11
Transfer to 0.

Therefore, there are three types of files received by the document receiving section 133. A document having a multiple document transfer program that realizes the function of transferring multiple documents;
Document list and general documents. The document file having the multiple document transfer program is as described in FIG.

The document receiving section 133 determines the type of the received file (steps S74, S75). If it is a document list, since the document requesting device 120 does not have the multiple document transfer function, an error is displayed and the process ends (step S7).
6). Even when the document is a normal document (document A), the multiple document transfer request process is not performed, the received document A is displayed, and the received document A is displayed in the local file cache area 121.
The data is saved in a and the process ends (step S77).

If the document A includes the plural document transfer program, the control is transferred to the plural document transfer program and the following processing is performed. That is, the plural document transfer program first displays the document A and stores it in the local file cache area 121a, and at the same time, uses the document request unit 132 to request a document list designated by the document list name 902. The document providing device 11
0 (step S78). As a result, the file is transferred from the document providing apparatus 110 and is received by the document receiving unit 133. If the file received by the document receiving unit 133 is not the document list, an error occurs (steps S79 and S76). If it is a document list, the multiple document request transmission process of steps S80 to S84 using the received document list is started under the control of the multiple document transfer program.

In this multiple document request transmission process, first, the multiple document transfer program selects one untransferred document as a file transfer request target document from the documents listed in the document list (step S80). When the document file for which the file transfer request is made is selected (step S8)
1) The multi-document requesting unit 138 determines whether the selected document type matches the transfer condition (step S82). The transfer condition is to prevent unnecessary transfer of a document file of a type that cannot be used by the document requesting device 120 in consideration of the display / reproduction function of the document requesting device 120, and may be a still image, a moving image, a voice, or the like. It is determined in advance according to the type of file and the display / reproduction capability of the document requesting device 120.

If the selected document type does not satisfy the transfer condition, steps S80 to S82 are executed again to judge whether another document is selected and the transfer condition is satisfied.

If the selected document type satisfies the transfer condition, the plural document transfer program uses the document requesting unit 132 to send a file transfer request for the document to the HTT.
It is transmitted to the document providing program 150 in the P format (step S83). The document providing program 150 transfers the document file designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. This document file is received by the document receiving unit 133 and stored in the local file cache area 121a (step S8).
4).

The processing of steps S80 to S84 is repeatedly executed until there are no unselected documents among the documents listed in the document list, and it is determined whether or not the transfer condition is satisfied each time the document is selected.

As described above, also in the file transfer method performed in the procedure of FIG. 7, transfer conditions are determined in advance in accordance with the types of files such as still images, moving images, and audio, and the display / reproduction capability of the document requesting device 120. Only the selected document file can be transferred from the document providing apparatus 110 to the document requesting apparatus 120, and the storage medium 1 by transferring a file that cannot be used by the document requesting apparatus 120
It is possible to prevent waste of 21 and meaningless increase of network traffic.

FIG. 8 shows a second configuration example of a program used in a client / server system to which the file transfer method of the present invention is applied. The program configuration here is such that a plurality of related document files are linked in advance in the document providing apparatus 110 rather than issuing a plurality of document transfer requests in sequence, and the linked file is a file from the document requesting apparatus 120. This corresponds to an example of transferring to the document providing apparatus 110 in response to a transfer request.

In the system of FIG. 8, the document providing apparatus 110 operates the document providing program 150. The document providing program 150 includes a request acceptance unit 151 and a request processing unit 152. The request acceptance unit 151 is a program that accepts a request from the document display program 130 operating in the document providing device. The request processing unit 152 is a program that performs specific processing in response to the request received by the request receiving unit. For example, when the request receiving unit receives the document file transfer request 140, the corresponding document 111 or the linked document 112 is searched from the storage medium 156, and when the corresponding document is found, the document file transmission 141 is performed.

In the document requesting device 120, the document display program 130 operates. The document display program 130 is provided with a linked document expansion unit 139 instead of the plural document transfer request unit 138 of FIG. The concatenated document expanding unit 138 is a program for expanding the concatenated document received from the document receiving unit 133 into each document.

Next, referring to the flowchart of FIG.
Document display program 130 executed by the system of FIG.
A specific operation procedure of will be described. First, the user or the program issues a file transfer request to request the transfer and display of the document (step S91). For this, the above-mentioned URL which is an identifier for uniquely specifying a document may be used. For example, http: // isl. rdc. tosh
iba. co. jp / index. If it is specified as html, the transfer protocol is HTTP, the server, that is, the connection destination document providing apparatus name is isl. rdc. toshib
a. co. jp, the file name is index. It is uniquely specified that the document is specified by html. Less than,
The identifier will be described as A.

Next, the request receiving unit 136 receives this display request (step S92), and the document requesting unit 132 sends the document A.
The file transfer request is transmitted to the document providing program 150 in the HTTP format (step S93). The document providing program 150 transfers the document A designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. In this case, if the document providing apparatus 110 holds the linked document corresponding to the document A designated by the file transfer request, the linked document is transferred to the document requesting apparatus 110.

Therefore, there are two types of files received by the document receiving section 133. It is a concatenated document created by concatenating a plurality of documents and a general document. The consolidated document is
It is configured by connecting a plurality of compressed document files compressed in document file units, and an example thereof is shown in FIG.

In FIG. 10, <CONCATENAT
E> is a header indicating that the file is a concatenated file. Next, the document A specified by the document file request is combined with the compressed document for each file starting from the document A. Each document is arranged in the order of an identifier that uniquely identifies the document, a size after compression, and a compressed document.

The document receiving unit 133 determines whether or not the received file is a concatenated document file (step S94). If it is a normal document A, the document A is displayed and stored in the local file cache area 121a, and the process is terminated (step S95). If it is a linked document, the receiving process of the linked document is continuously performed (step S96).

From the document providing device 110 to the document requesting device 12
While the linked document is being transferred to 0, the document display program 130 checks whether or not the transfer abort condition is satisfied (step S97). The transfer termination condition is for limiting the amount of use of the storage medium 121 of the document requesting device 120 and the communication time through the network, and the total data size of the files transferred from the document providing device 110 is a predetermined value. When the file transfer time exceeds a preset value, or when an explicit transfer stop request (interrupt) is received from the user or program, it is determined that the transfer abort condition has been met. It is preferable.

Specifically, when it is desired to receive only the data having a size equal to or less than a certain amount, the amount of data received by the document receiving unit 133 may be measured, and when the amount reaches a certain value, the process may be terminated. Alternatively, when it is desired to keep the size of the free space of the storage medium 121 at a constant value, for example, the upper limit of the receivable data size is determined from the current free space, and the document receiving unit 133 is determined.
When the amount of data received at reaches the upper limit value, it may be terminated. Alternatively, if it is determined that the transfer abort condition is satisfied after a certain time has elapsed after the file transfer was requested, a timer is set so that an interrupt is generated after a certain time has elapsed after the transfer request was sent, and the interrupt is set. You can abort the transfer at the time of receiving. The received data amount may be detected using the data size information of each compressed file included in the concatenated file.

When the transfer abort condition is satisfied, the receiving process is aborted at that time, and the portion of the concatenated document that has been successfully transferred is decompressed for each document to be restored into an individual document and stored in the local file cache area 121a. (Step S98). Further, when the transfer termination condition is not satisfied during the transfer of the linked document and the transfer completion of all the linked documents is detected (step S96b), all the documents forming the linked document are restored to the individual documents. Then, it is stored in the local file cache area 121a (step S99).

According to the file transfer method of FIG. 9, for example, http: // is in the linked document of FIG.
l. rdc. toshiba. co. jp / newsp
aper / image / image. If the transfer is aborted during the transfer of the gif, the previous http: // i
sl. rdc. toshiba. co. jp / news
paper / article2. It is possible to restore and use up to html.

Next, referring to the flowchart of FIG. 11, the document display program 1 executed by the system of FIG.
A second example of the specific operation procedure of 30 will be described.
This processing procedure is an example in which the linked document expansion unit 139 is not prepared in the document requesting device 120 from the beginning, but the program is transferred from the document providing device 110 to the document requesting device 120.

First, the user or program issues a file transfer request to request document transfer and display (step S101). For this, the above-mentioned URL which is an identifier for uniquely specifying a document may be used. For example, htt
p: // isl. rdc. toshiba. co. jp /
index. If it is specified as html, the transfer protocol is HTTP, the server, that is, the connection destination document providing apparatus name is isl. rdc. toshiba. co. jp, the file name is index. It is uniquely specified that the document is specified by html. Hereinafter, the identifier will be described as A.

Next, the request receiving unit 136 receives this display request (step S102), and the document requesting unit 132 sends a file transfer request for the document A to the document providing program 150 in HTTP format (step S103). The document providing program 150 transfers the document A designated by the file transfer request from the document requesting unit 132 to the document requesting device 120. In this case, if there is a linked document corresponding to the document A specified by the file transfer request and it contains a linked document expanding program, the linked document containing the linked document expanding program is transferred to the document requesting device 110. It

Therefore, there are two types of files received by the document receiving section 133. A consolidated document including a consolidated document expansion program and a general document. The linked document is shown in Figure 1.
As described in 0, it is configured by concatenating a plurality of compressed document files compressed in document file units, and the concatenated document is concatenated in the same format as that shown in FIG. 5 (a document list is not included). Includes a document extraction program.

The document receiving unit 133 determines whether or not the received file is a linked document including the linked document expansion program (step S104). If it is a normal document A, the document A is displayed and stored in the local file cache area 121a, and the process is terminated (step S).
105). If it is a linked document including the linked document expanding program, the receiving process of the linked document is continuously performed (step S106).

From the document providing device 110 to the document requesting device 12
While the linked document is being transferred to 0, the document display program 130 checks whether or not the transfer abort condition is satisfied (step S107). The transfer termination condition is for limiting the amount of use of the storage medium 121 of the document requesting device 120 and the communication time through the network.
When the total data size of the files transferred from the document providing apparatus 110 exceeds a preset value, when the file transfer time exceeds a preset value, or an explicit transfer stop request from the user or program. When the (interrupt) is received, it is determined that the transfer abort condition is satisfied.

When the transfer abort condition is satisfied, the receiving process is aborted at that point, and the portion of the concatenated document that has been successfully transferred is decompressed for each document by the concatenated document decompression program and restored to an individual document. The data is stored in the area 121a (step S108). Further, when the transfer termination condition is not satisfied during the transfer of the linked document and the completion of the transfer of all the linked documents is detected (step S106b), all the documents forming the linked document are individually processed by the linked document expansion program. Is restored to the document and stored in the local file cache area 121a (step S109).

In the system of FIG. 8, an example of transferring a concatenated document obtained by compressing each document has been described, but a file transmitted from the document requesting device 120 without such compression. The document providing apparatus 11 sets the concatenated document concatenated so that the document specified by the transfer request is at the head.
It may be transferred from 0 to the document requesting device 120.

In this case, since the document A requested by the user is first transferred to the document requesting device 120, even if the transfer abort condition is satisfied and the transfer of the concatenated document is aborted midway, at least the user is at that point. The transfer of the requested document A has a high probability of being completed and can be utilized.

[0093]

As described above, according to the present invention, in the system in which the document file is transferred from the server to the client and displayed, the transfer of the document is not fast or the free space of the storage medium owned by the client is small. In this case, the transfer can be aborted in the middle, and when transferring multiple documents or concatenating multiple documents and transferring as one document, the document that has been transferred at the time of abortion can be used by the client. Becomes It is also possible to transfer only usable documents according to the document display / playback capability of the client.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a client / server system to which a file transfer method according to an embodiment of the present invention is applied.

FIG. 2 is a flowchart showing a first example of a multiple file transfer processing procedure of a WWW client program used in the system of FIG.

FIG. 3 is a diagram showing an example of a document list referenced by a WWW client program used in the system of FIG.

4 is a flowchart showing a second example of a multiple file transfer processing procedure of the WWW client program used in the system of FIG.

5 is a diagram showing an example of a document file including a plurality of document transfer programs transferred from a WWW server to a WWW client in the system of FIG.

6 is a flowchart showing a third example of a multiple file transfer processing procedure of the WWW client program used in the system of FIG.

7 is a flowchart showing a fourth example of a multiple file transfer processing procedure of the WWW client program used in the system of FIG.

FIG. 8 is a block diagram showing another configuration of the client / server system to which the file transfer method according to the embodiment of the present invention is applied.

9 is a flowchart showing a first example of a linked document transfer processing procedure of a WWW client program used in the system of FIG.

FIG. 10 is a diagram showing an example of a linked document transferred by the system of FIG.

11 is a flowchart showing a second example of a linked document transfer processing procedure of the WWW client program used in the system of FIG.

[Explanation of symbols]

110 ... Document providing device, 120 ... Document requesting device, 121
... storage medium 121a ... local file cache area 130 ... document display program 131 ... connection unit, 1
32 ... Document requesting unit, 133 ... Document receiving unit, 134 ... Document storing unit, 135 ... Document displaying unit, 136 ... Request receiving unit, 1
37 ... Connection release unit, 138 ... Plural document transfer request unit, 13
9 ... Linked document expansion unit, 150 ... Document providing program, 1
51 ... Request accepting unit, 152 ... Request processing unit, 156 ... Storage medium.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Shimokawa 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Incorporated Toshiba Research and Development Center

Claims (9)

[Claims] 1. A file transfer method used in a client / server system including a server that provides a service for providing a file and a client that requests a file transfer from the server, wherein a single file issued from the client A plurality of file transfer requests for the one file request so that a plurality of files including a file specified in the file request and files related to the request are transferred from the server to the client Are sequentially transmitted to the server, and when it is determined that a transfer termination condition specified in advance is satisfied, transmission of all remaining file transfer requests to be transmitted thereafter is stopped. File transfer method. 2. The file transfer method according to claim 1, wherein when the total data size transferred from the server to the client exceeds a specified value, it is determined that the transfer abort condition is satisfied. 3. The file transfer method according to claim 1, wherein when the file transfer time from the server to the client exceeds a specified value, it is determined that the transfer abort condition is satisfied. 4. The file transfer method according to claim 1, wherein when the user of the client issues an interrupt instruction, it is determined that the transfer abort condition is satisfied. 5. A file transfer method used in a client / server system including a server that provides a service for providing a file and a client that requests a file transfer from the server, wherein a single file issued from the client In response to the request, a concatenated file formed by concatenating a plurality of compressed files in units of files is transferred from the server to the client, and when it is determined that a prespecified transfer abort condition is satisfied, the server performs the A file transfer method characterized in that transfer of the concatenated file to the client is terminated, and each compressed file transferred to the client before the transfer is terminated can be restored in file units. 6. A file transfer method used in a client / server system including a server that provides a service for providing a file and a client that requests a file transfer from the server, wherein a single file issued from the client In response to the request, a concatenated file in which a plurality of files are concatenated so that the file specified by the file request is at the top is transferred from the server to the client, and a prespecified transfer abort condition is satisfied. When the determination is made, the transfer of the concatenated file from the server to the client is terminated, and the file transfer method. 7. The file transfer according to claim 5, wherein when the total data size transferred from the server to the client exceeds a specified value, it is determined that the transfer abort condition is satisfied. Method. 8. The file according to claim 5, wherein when the transfer time of the concatenated file from the server to the client exceeds a specified value, it is determined that the transfer abort condition is satisfied. Transfer method. 9. A file transfer method used in a client / server system including a server that provides a service for providing files and a client that requests file transfer from the server, wherein a single file request from the client is made. Among a plurality of files including a designated file and files related to the designated file, a transfer condition determined in advance according to a file type such as a still image, a moving image, a sound and the display / playback capability of the client is satisfied. A file is selected, a file transfer request that specifies it for each selected file is sent to the server, and only files that match the transfer condition among the plurality of files are sent from the server to the client. A file transfer method characterized in that