System and method for searching in structured documents

A structured document searching system comprising:

• a plurality of document managing apparatuses that stores a structured document in a distributed manner;
• a searching apparatus that is connected to the document managing apparatuses via a network and that is operable to search in the structured document from the document managing apparatuses;
• and
• a client apparatus that is connected to the document managing apparatuses and the searching apparatus via a network and that is operable to transmit a search request for the structured document to the searching apparatus, wherein
• each of the document managing apparatuses includes:
• a document storing unit that stores a partial-character-string of the structured document corresponding to a predetermined one of structure elements that are used as units of a logical structure of the structured document;
• a request receiving unit that receives an acquisition request for the partial-character-string from other ones of the document managing apparatuses and the searching apparatus;
• a first acquiring unit that acquires the partial-character-string from the document storing unit based on the received acquisition request, and judges whether a portion of the acquired partial-character-string is stored in any one of the other document managing apparatuses, based on information that is contained in the acquired partial-character-string and indicates that a portion of the acquired partial-character-string is stored in one of the other document managing apparatuses;
• a first request transmitting unit that transmits an acquisition request for the portion of the partial-character-string to the one of the other document managing apparatuses that is judged to store the portion of the partial-character-string, when it is judged that the portion of the partial-character-string is stored in the one of the other document managing apparatuses;
• and
• a first result transmitting unit that transmits the acquired partial-character-string to the searching apparatus, and
• the searching apparatus includes:
• a structure information storing unit that stores structure IDs and apparatus IDs being kept in correspondence with each other, each of the structure IDs uniquely identifying one of the structure elements, and each of the apparatus IDs uniquely identifying one of the document managing apparatuses that stores the partial-character-string corresponding to the structure elements;
• a search request receiving unit that receives the search request from the client apparatus;
• a searching unit that acquires from the structure information storing unit one of the structure IDs of one of the structure elements that satisfies the received search request;
• a second acquiring unit that acquires from the structure information storing unit one of the apparatus IDs of one of the document managing apparatuses that is in correspondence with the acquired structure ID;
• a second request transmitting unit that transmits the acquisition request to the one of the document managing apparatuses that is identified with the acquired apparatus ID;
• a partial-character-string receiving unit that receives the partial-character-string from one or more of the document managing apparatuses;
• and
• a second result transmitting unit that connects the received partial-character-strings to one another and transmits a document acquired by connecting the partial-character-strings to the client apparatus, when the partial-character-string is received from each of the document managing apparatuses.