JP2008146178A - Structured document processing device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the reliability of error processing even with a compact apparatus by verifying the adequacy of a structured document with a saved memory without maintaining all information on a schema. <P>SOLUTION: This structured document processing device performs verification by reading the structured document as a verification object by one node and by reading only the required amount of a schema for verifying the node (S207). After completing the verification of one node, it is determined whether or not the maintained schema information may be required in future and if it is not required, it is abandoned (S208, S210). After that, these steps are repeated until reading through the entire structured document. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structured document verification technique.

  In recent years, XML (Extensible Markup Language) has become widespread as a document and application setting file to be handled on a computer and as a format for data communication. XML is a standard for giving meaning to text by a start tag ('<' tag name '>') and an end tag ('</' tag name '>'). In XML, the name of a tag is arbitrary, and the specific meaning of a tag with a certain name depends on the respective formats created based on XML.

  For example, XHTML is a standard for displaying a document including a link to another document on a screen. In this standard, the tag b means that the character is bold. In other words, if there is a description “This is very <b> important </ b>”, “this is very important”, and the “important” part is displayed in bold.

  Since anyone can freely create a language based on XML, there are a number of formats based on XML, such as those defined by standardization organizations and those defined by individuals.

  When an XML document is processed, an analyzer dedicated to XML (XML parser) is usually used. The XML parser reads an XML document, analyzes it, divides it into units (nodes) constituting XML such as elements and character data, and passes them to the application.

  Here, there are two types of errors when processing XML. That is, a grammatical violation as XML (a well-formed error) and a grammar error (validity error) of each format using XML.

  For example, a document “<A> Hello </ B>” has different names for the start tag and the end tag. This is a document that violates the XML grammar. On the other hand, the document “<XYZ> Hello </ XYZ>” satisfies the XML grammar. However, since there is no <XYZ> tag in XHTML, an error occurs. Such an error for each format-specific grammar is called a validity error, and verification of whether there is a validity error is called validation.

  In order to perform validity verification, a document (schema) that defines the grammar of each format is required. There has been a verifier that reads a schema and an XML document and verifies whether the XML document is valid. For example, an XML parser attached to JAVA (registered trademark) is an example. In addition, a method has been proposed in which a table for specifying a proxy necessary for verifying each node of the XML document is prepared, and the proxy specified by the table performs verification. Yes.

JP 2005-63416 A

  However, the JAVA (registered trademark) verifier once reads all the schemas and stores them in the memory, and verifies the XML document using the stored schema information. Similarly, in the method of Patent Document 1, it is necessary to read all schemas in advance in order to create a table for specifying a proxy. For this reason, when the data size of the schema is large, a large amount of memory is required, and there is a problem that verification cannot be performed especially on a device with a small amount of memory.

  An object of the present invention is to provide a structured document processing apparatus capable of verifying the validity of a structured document without consuming a large amount of memory.

  A structured document processing apparatus according to an aspect of the present invention includes a structured document sequential analysis unit that sequentially analyzes a structured document and a schema described in the structured document for each node, and the structured document sequential analysis unit. Schema information analysis means for obtaining schema information which is schema constraint information from schema node information obtained by analyzing the schema, and holding means for holding the schema information obtained by the schema information analysis means A schema information amount judging means for judging whether the schema information necessary for verifying the current node of the structured document is obtained from the structure constraint information of the schema information, and the structured document sequential analyzing means, Validity verification means for verifying validity using the schema information for the node obtained by analyzing the structured document; From the structure constraint information of the schema information, the schema information necessity judgment means for judging whether the schema information held by the holding means is necessary for subsequent verification, and the schema necessity judgment means judge that the schema information is unnecessary. And discarding means for discarding the schema information.

  According to the present invention, when the validity of a structured document is verified using a schema, verification can be performed without retaining all information of the schema, so that it can be realized with a small amount of memory. Processing reliability can be improved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, It shows only the specific example advantageous for implementation of this invention. In addition, not all combinations of features described in the following embodiments are essential as the problem solving means of the present invention.

<Embodiment 1>
The structure of the structured document processing apparatus in the first embodiment of the present invention is shown in FIG.

  In the figure, a CPU 101 is a system control unit and controls the entire apparatus. The ROM 102 stores CPU control programs and various fixed data. The RAM 103 is composed of SRAM, DRAM, and the like, and stores program control variables and the like. Various setting parameters, various work buffers, and the like are also stored in the RAM 103. The storage unit 104 is a hard disk or the like, and stores file data.

  The structured document sequential analysis unit 105 analyzes the structured document and the schema described in the structured document, and stores the node information in the RAM 103. The schema information analysis unit 106 analyzes the node information obtained by analyzing the schema by the structured document sequential analysis unit 105 as schema constraint information, and stores it in the RAM 103 as schema information that can be used by the structured document verification unit 108. To do.

  The structured document sequential analysis unit 105 can perform sequential processing. Sequential processing means that it is possible to read and use a part of the document from the beginning of the document one by one, and discard information that is no longer needed as appropriate, rather than reading all of the target document at once. To do.

  The schema information amount determination unit 107 determines whether the node read by the structured document sequential analysis unit 105 can be verified with the currently held schema information. The structured document verification unit 108 verifies whether or not the node stored in the RAM 103 is valid using the schema information stored in the RAM 103. The schema information necessity determination unit 109 determines whether or not the schema information held in the RAM 103 will be used thereafter.

  This structured document processing apparatus verifies the structured document stored in the storage unit 104 using the schema stored in the storage unit 104. In this embodiment, the structured document is written in a format based on XML, and the schema is described in RELAX NG (http://www.relaxng.org/). However, the description in the present embodiment excludes parts that are out of the essence of the present invention for simplification of explanation.

  An example schema is shown in FIG. In the RELAX NG schema, an element element represents an element that should exist in the XML document, and a name attribute describes the name of the element. Further, when there is an element element as the content of the element element, it indicates that the element inside the element must exist as the content of the element outside the element element. When the content of the element element is a text element, it means that the element has an arbitrary character string. The interleave element means that the elements described therein must exist, but the order does not matter. The zeroOrMore element means that the element described in the element can exist repeatedly, and there may not be one. In addition, there is a choice element indicating that any one of a plurality of elements is present.

  That is, the schema of FIG. 3 has an element called person, and the contents must first have a familyName and a givenName element in no particular order. After that, it means that the certification element is repeated zero or more times. The contents of the familyName, givenName, and certification elements can be arbitrary character strings.

  Examples of documents valid for this schema are shown in FIGS. Each has a person element in which familyName and givenName are present, and then a certification element is repeatedly present.

  In contrast, FIG. 6 is an example of a document that is not valid for the schema. This document contains an element called age (604), but this element is not valid because it does not exist in the schema.

  FIG. 2 shows a processing flow of the structured document processing apparatus according to the first embodiment. Here, FIG. 3 is used as an example schema and FIG. 5 is used as a document to be analyzed. First, it is confirmed whether all documents to be verified have been read (step S202). If not all have been read yet, one node of the document to be verified is read (step S203). A node is a unit constituting a structured document, such as an XML start tag, end tag, and character data. In this example, a <person> tag (501) is read.

  Next, it is confirmed whether or not it has schema information necessary for verifying the read node (step S204). At the first stage, no schema is read and necessary schema information is not held, so one node is read (step S205), analyzed as schema information, and stored in the RAM 103 (step S206). Since the first node (301) of the schema is an element tag and there is person in the name attribute, it can be seen that the first element must be person.

  Next, it is determined again whether the schema information necessary for verifying the read node is present (step S204). This determination can be made from the structure constraint information of the schema information. The schema structure by RELAXNG mainly consists of four types of structures: sequential, selection, random order, and repetition. The sequential structure represents that specified elements must exist in that order, such as when element elements are continuous. The selection structure indicates that one of a plurality of candidates only needs to exist. An unordered structure is one in which a plurality of designated elements must exist, but the order is not important. The repetitive structure represents that a given element can exist repeatedly. Selection, random order, and repetition are represented by choice, interleave, zeroOrMore, etc. in RELAXNG, respectively.

  In the case of the selected structure and the unordered structure among these four configurations, verification cannot be performed unless all the contents are held. This is because there are a plurality of constraint candidates for the node and it is necessary to deal with all of them. On the other hand, in the case of a sequential structure or a repetitive structure, since there is only one candidate node that can exist, verification can be performed by reading only one constraint. Further, when verification is in progress in an unordered structure, it is determined that it is not necessary to read because verification is possible with the schema information held. That is, in the case of RELAX NG, if the read schema is an element or a text element, it can be determined that verification can be performed at that stage. On the other hand, in the case of a choice or interleave element, it is determined that it is necessary to read the end of the element. Further, during the verification of the element in the interleave element, when the interleave element is read to the end when it is first read, it can be determined that it is not necessary to read the schema any more.

  As a result of such determination, since it is the element element (301) when it is first read, it is determined that verification is possible at this stage, and verification is performed (step S207). Since the element specified in the schema matches the held node, it is determined to be valid. If it is any other node, it is regarded as invalid and an error occurs (steps S208 and S209).

  Next, it is determined whether the currently held schema information is necessary in the future (step S210). This determination can also be made from the structure constraint information of the schema information. Of the four types of structures described above, it can be determined that it is necessary to retain schema information because the same structure may continue in the repetitive structure. A repetitive structure can be determined to be unnecessary only when the next element of the repetitive structure appears and it can be determined that the repetitive structure has ended. Conversely, in the case of the other three structures, it can be determined that they will not be used again. If it is determined that this is unnecessary, the schema information stored in the RAM 103 is discarded (step S211).

  Since the schema element 301 in FIG. 3 is not a repetitive structure, it is determined to be unnecessary, and this information is discarded.

  At this stage, since all the verification target documents have not been read yet, the next node is read (steps S202 and 203). The node of the verification handling document to be read next is a familyName element (502). The schema to be read is an interleave element (302). Since the internal elements of the interleave element are out of order, it is determined that the interleave element is necessary up to the end of the interleave (305) to perform verification, and all of the elements are read. As a result, it can be determined that the result 502 is appropriate. The next giveName element (503) can be verified in the same manner except that it is not necessary to read the schema because it is in the interleave element.

  Similarly, when the certification element (504) is read, the zeroOrMore element (306) is read. Since this is an iterative structure, it is determined that verification is possible by reading up to the element element (307) which is the first constraint. And verify. After the verification, it is determined whether the stored schema information is necessary. However, in the case of a repetitive structure such as a zeroOrMore element, the certification element 505 can be verified using the schema information stored.

  The above processing is repeated, the verification target document is read to the end, and if no validity error occurs, it can be determined that the document is valid for the schema.

<Embodiment 2>
FIG. 7 shows the configuration of the structured document processing apparatus according to the second embodiment of the present invention. In this method, when a schema that cannot be sequentially processed is received from an external device on the network or the like, the schema is converted and stored to perform sequential processing.

  In FIG. 7, reference numerals 701 to 709 are the same as 101 to 109 in FIG. In FIG. 7, a schema conversion unit 710 and a network interface 711 are further added. The schema conversion unit 710 converts the schema information read by the schema sequential analysis unit 706 so as to enable sequential processing and outputs the converted information. The network interface 711 is a network interface such as a LAN board or a modem, and enables communication with other devices on the network.

  This structured document processing apparatus is connected to the network shown in FIG. In FIG. 8, reference numeral 801 denotes a provider, which provides some service to other devices on the network. Reference numeral 802 denotes a requester that requests a service from a provider. These devices are connected via a network 803 and can communicate with each other. The structured document processing apparatus according to this embodiment corresponds to a requester among them.

  In order for this structured document processing apparatus (requester) to newly use a provider's service, it is necessary to first know the format of the message to be transmitted or received to the provider, that is, the schema. The schema is added manually or by obtaining it from a provider.

  In general, schemas are often modularized for human viewing, maintenance, and extensibility, and sequential processing is often impossible as they are.

  An example of a schema that cannot be sequentially processed is shown in FIG. This example also describes RELAX NG in a simplified format. Here, the element “start” indicates a place to be the starting point of the entire schema. That is, the first element element (903) in the start element represents the restriction of the head element of the XML document according to this schema. In this example, it is addressBook. Furthermore, it can be seen from the element element (904) that an element named "name" is required next. The element ref in 905 indicates that the one defined elsewhere is used. The definition is described by an element “define”, and the reference destination is specified by the name attribute of the ref element. In other words, the ref element (905) means that a portion from 910 to 913 at the back of the document is referred to.

  Thus, by placing a specific part in another place and referring to it, there is an advantage that it is easy to grasp the entire schema configuration and it can be reused in another schema. However, in the case of a schema that references the back of the document, verification cannot be performed unless the reference destination is read, and sequential processing cannot be performed. Therefore, it is necessary to convert the schema according to the flow of FIG.

  First, the file is stored in the storage device 704 as a plurality of files divided into a part that can be a reference destination and other parts in the schema (step S1402). Next, a new sequential processing schema is generated by combining the reference destination with the saved file while reading the file other than the reference destination again (step S1403). Thereafter, XML is received by the network interface (step S1404), and analysis and verification are performed (step S1405).

  Details of the file saving process in step S1402 are shown in FIG.

  First, one node of the schema is read (step S1502). It is confirmed whether or not the node is a define element (step S1503), and nodes other than the define element are output as they are (steps S1504 and 1510). If it is a define element, it is stored in another file (step S1505). At this time, the file name may be arbitrary as long as there is no other same one, and the saved file name and the reference name (value of the name attribute of the define element) are added to the table for saving (step S1506). Here, nameData. Suppose that it was saved with the name rng. Then, all the nodes up to the end of the define element are output to the newly created file (steps S1507, 1508, 1509). In this way, all nodes in the schema are output to a separate file.

  For the schema of FIG. 9, as a result, a file having information other than the reference destination (FIG. 10), a file having information referred to by the reference name “nameData” (FIG. 11), and a table of reference names and file names ( FIG. 12) is generated.

  Next, FIG. 16 shows details of the processing for creating the sequential processing schema in step S1403.

  First, a schema having information other than the reference destination is read node by node (step S1602), and contents other than the contents of the ref element are output as they are (step S1604). In the case of the ref element, the file name for the reference name is checked from the table (step S1605), and all parts other than the define tag of the file are output as they are (step S1606). The above processing is performed for all nodes (step S1607). As a result, the schema of FIG. 13 is output. In this schema, the description of the reference is solved, and sequential processing is performed in which processing is performed in order from the top of the schema. The processing flow when actually verifying the XML document is the same as in the first embodiment.

  In this embodiment, XML is used as the format of the structured document, and RELAX NG is used as the schema language. However, other structured document formats and schema languages can be used. For example, in the case of W3C XML Schema, the same processing can be performed by sequentially applying selection, random order, and repeating structure to the sequence, choice, all, maxOccures elements, and the like, and regarding the ref element as a reference structure.

  In the embodiment, the verification is performed at the time of the XML analysis. However, the XML can be generated after the verification, and can be used for the verification at the time of generating the XML.

  In this embodiment, when the schema information amount is determined, the verification is performed after reading all the elements in the choice element. However, the verification can be performed by sequentially reading the elements in the choice. For example, when there are three element elements in the choice element, it is read and verified one by one, and when it is valid, the node is determined to be valid, and when all three are not valid, the validity violation By determining that, memory saving can be further realized.

(Other embodiments)
Although the embodiments of the present invention have been described in detail above, the present invention may be applied to a system constituted by a plurality of devices or may be applied to an apparatus constituted by one device.

  In the present invention, a program for realizing each function of the above-described embodiments is supplied directly or remotely to a system or apparatus, and a computer included in the system or apparatus reads and executes the supplied program code. Can also be achieved.

  Accordingly, since the functions and processes of the present invention are implemented by a computer, the program code itself installed in the computer also implements the present invention. That is, the computer program itself for realizing the functions and processes is also one aspect of the present invention.

  In this case, the program may be in any form as long as it has a program function, such as an object code, a program executed by an interpreter, or script data supplied to the OS.

  Examples of the recording medium for supplying the program include a flexible disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, and CD-RW. Examples of the recording medium include a magnetic tape, a non-volatile memory card, a ROM, a DVD (DVD-ROM, DVD-R), and the like.

  The program may be downloaded from a homepage on the Internet using a browser on a client computer. That is, the computer program itself of the present invention or a compressed file including an automatic installation function may be downloaded from a home page to a recording medium such as a hard disk. Further, it is also possible to divide the program code constituting the program of the present invention into a plurality of files and download each file from a different home page. That is, a WWW server that allows a plurality of users to download a program file for realizing the functions and processing of the present invention on a computer may be a constituent requirement of the present invention.

  Further, the program of the present invention may be encrypted and stored in a storage medium such as a CD-ROM and distributed to users. In this case, only the user who cleared the predetermined condition is allowed to download the key information to be decrypted from the homepage via the Internet, decrypt the program encrypted with the key information, execute it, and install the program on the computer May be.

  Further, the functions of the above-described embodiments may be realized by the computer executing the read program. Note that an OS or the like running on the computer may perform part or all of the actual processing based on the instructions of the program. Of course, also in this case, the functions of the above-described embodiments can be realized.

  Furthermore, the program read from the recording medium may be written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Based on the instructions of the program, a CPU or the like provided in the function expansion board or function expansion unit may perform part or all of the actual processing. In this way, the functions of the above-described embodiments may be realized.

It is a block diagram which shows the structure of the structured document processing apparatus in 1st embodiment of this invention. It is a flowchart which shows the verification process of the structured document processing apparatus in 1st embodiment of this invention. It is a figure which shows the example of a schema. , FIG. 4 is a diagram illustrating an example of a document valid for the schema of FIG. 3. FIG. 4 is a diagram illustrating an example of a document that is not valid for the schema of FIG. 3. It is a block diagram which shows the structure of the structured document processing apparatus in 2nd embodiment of this invention. It is a figure which shows the relationship between the structured document processing apparatus and other apparatus in 2nd embodiment of this invention. It is a figure which shows the example of the schema containing the description of the reference in a schema. It is a figure which shows the example of the schema which excluded the description of the reference. It is a figure which shows the example of the result of outputting only the location referred. It is a figure which shows the example of the table which shows the relationship between a reference name and a file name. It is a figure which shows the example of the schema of the result converted so that sequential processing is possible. It is a flowchart which shows the outline | summary of a process of the structured document processing apparatus in 2nd embodiment of this invention. It is a flowchart which shows the detail of the primary process of schema conversion. It is a flowchart which shows the detail of the secondary process of schema conversion.

Claims (7)

Structured document sequential analysis means for sequentially analyzing the structured document and the schema described in the structured document for each node;
Schema information analysis means for obtaining schema information which is schema constraint information from the node information of the schema obtained by analyzing the schema by the structured document sequential analysis means;
Holding means for holding the schema information obtained by the schema information analyzing means;
Schema information amount determination means for determining whether or not the schema information necessary for verifying the current node of the structured document is obtained from the structure constraint information of the schema information;
Validity verification means for verifying validity using the schema information for nodes obtained by the structured document sequential analysis means analyzing the structured document;
Schema information necessity judgment means for judging whether or not the schema information held by the holding means is necessary for subsequent verification from the structure constraint information of the schema information;
A discarding unit that discards schema information determined to be unnecessary by the schema necessity determining unit;
A structured document processing apparatus comprising: Structured document sequential generation means for receiving node information of the structured document and sequentially generating the structured document;
Structured document sequential analysis means for sequentially analyzing the schema described in the structured document for each node;
Schema information analysis means for obtaining schema information which is schema constraint information from the node information of the schema obtained by analyzing the schema by the structured document sequential analysis means;
Holding means for holding the schema information obtained by the schema information analyzing means;
Schema information amount judging means for judging whether or not the schema information necessary for verifying the current node is obtained from the structure constraint information of the schema information;
Validity verification means for verifying validity using the schema information for the node information of the structured document;
Schema information necessity judgment means for judging whether or not the schema information held by the holding means is necessary for subsequent verification from the structure constraint information of the schema information;
A discarding unit that discards schema information determined to be unnecessary by the schema necessity determining unit;
A structured document processing apparatus comprising: A reference destination file creation unit that outputs a portion that may be referred to from another location to the schema information obtained by the schema information analysis unit;
When the schema information obtained by the schema information analysis means has a description referring to another location, the contents of the file created by the reference destination file creation means are read and output, and the other location is referred to An output means for outputting the part which is not as it is,
The structured document processing apparatus according to claim 1, further comprising: A structured document sequential analysis step for sequentially analyzing the structured document and the schema described in the structured document for each node;
A schema information analysis step for obtaining schema information which is schema constraint information from the schema node information obtained by the schema analysis in the structured document sequential analysis step;
A storage step of storing the schema information obtained in the schema information analysis step in a memory;
A schema information amount determination step for determining whether the schema information necessary to verify the current node of the structured document is obtained from the structure constraint information of the schema information;
A validity verification step of performing validity verification using the schema information for the node obtained by the analysis of the structured document in the structured document sequential analysis step;
A schema information necessity determination step for determining whether or not the schema information stored in the memory is necessary for subsequent verification from the structure constraint information of the schema information;
A deletion step of deleting schema information determined to be unnecessary in the schema necessity determination step from the memory;
A structured document processing method characterized by comprising: A structured document sequential generation step of receiving node information of the structured document and sequentially generating the structured document;
A structured document sequential analysis step for sequentially analyzing the schema described in the structured document for each node;
A schema information analysis step for obtaining schema information which is schema constraint information from the schema node information obtained by the schema analysis in the structured document sequential analysis step;
A storage step of storing the schema information obtained in the schema information analysis step in a memory;
A schema information amount determining step for determining whether the schema information necessary for verifying the current node is obtained from the structure constraint information of the schema information;
A validity verification step of performing validity verification on the node information of the structured document using the schema information;
A schema information necessity determination step for determining whether or not the schema information stored in the memory is necessary for subsequent verification from the structure constraint information of the schema information;
A deletion step of deleting schema information determined to be unnecessary in the schema necessity determination step from the memory;
A structured document processing method characterized by comprising: A reference file creation step for outputting to a separate file a portion that may be referred to from another location in the schema information obtained in the schema information analysis step;
If the schema information obtained in the schema information analysis step has a description that refers to another location, the content of the file created in the reference destination file creation step is read and output, and the other location is referenced An output step that outputs the part that is not
6. The structured document processing method according to claim 4 or 5, further comprising:   A program for causing a computer to execute the structured document processing method according to any one of claims 4 to 6.

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