1. An ontology-integration-position specifying apparatus comprising: a class storage unit that stores class mapping information in which a class included in an integration-source ontology and a class included in an integration-destination ontology are associated with each other, at a time of integrating hierarchical ontologies in which an attribute held by a superclass is inherited by a subclass and an inheritance relation can be specified, the integrating being performed according to the inheritance relation; an attribute memory that stores attribute mapping information in which a superclass of an associated class, which is a class in the integration-source ontology and associated in the class mapping information, an attribute held by the superclass of the associated class, and an integration destination attribute which is an attribute of a class in the integration-destination ontology and corresponding to the associated class are associated with each other; a class specifying unit that specifies an integration target class, which is an object to be associated with a class included in the integration-destination ontology, from classes other than the associated class and included in the integration-source ontology; an attribute-mapping-information acquiring unit that acquires attribute mapping information of an attribute which is held by a superclass of the integration target class and which is associated with the integration destination attribute in the integration-destination ontology, from the stored attribute mapping information; an associated class specifying unit that specifies an associated class having a shortest distance from the integration target class via a common superclass with the integration target class, among the associated classes included in the class mapping information; an integration-destination-associated-class specifying unit that specifies an integration-destination-associated class included in the integration-destination ontology and associated with the associated class specified from the class mapping information; and a position specifying unit that follows the inheritance relation as a route from the integration-destination-associated class specified, and specifies a class in the integration-destination ontology having the integration destination attribute corresponding to the attribute mapping information acquired by the attribute-mapping-information acquiring unit as a position where the class associated with the integration target class is present.
3. The apparatus according to claim 1 , further comprising: a display information generator that generates display information including a hierarchical structure of the integration-source ontology and a hierarchical structure of the integration-destination ontology, wherein the class specifying unit specifies a class input as one selected by a user who refers to the display information generated, as the integration target class.