[size=3]这是个利用rule进行的查询推理。（前提已经把本体存入到数据库中）
public class tuilichaxun {
public static void searchOnto1(OntModel model){
/*设置规则*/
String rule = "[rule1:(?x http://www.owl-ontologies.com/Expert.owl#research ?y) " +
"(?y http://www.owl-ontologies.com/Expert.owl#associate ?z) " +
"->(?x http://www.owl-ontologies.com/Expert.owl#familiar_with ?z)]";
/*查询语句*/
String queryString = "PREFIX Expert:<http://www.owl-ontologies.com/Expert.owl#> " +
"SELECT ?expert ?subject " +
"WHERE {?expert Expert:familiar_with ?subject} ";
/*创建推理机*/
//使用默认jena推理机
Reasoner reasoner2 = new GenericRuleReasoner(Rule.parseRules(rule));
InfModel inf = ModelFactory.createInfModel(reasoner2, model);
Query query = QueryFactory.create(queryString);
QueryExecution qe = QueryExecutionFactory.create(query, inf);
ResultSet results = qe.execSelect();
/*打印结果*/
ResultSetFormatter.out(System.out, results, query);
qe.close();
}
/**
* @param args
*/
public static void main(String[] args) {
String DB_URL = "jdbc:mysql://localhost/expert1";
String DB_USER = "root";
String DB_PASSWD = "root";
String DB = "MySQL";
String DB_DRIVER = "com.mysql.jdbc.Driver";
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
IDBConnection con = s.connectDB(DB_URL,DB_USER, DB_PASSWD, DB);
System.out.println(con);
OntModel model = s.getModelFromDB(con, "expert");
tuilichaxun.searchOnto1(model);
}
}
运行结果：
-----------------------------------------------------------
| expert | subject |
===================================
| Expert:ChenJianer | Expert:Computer_Software_and_Theory |
-----------------------------------------------------------
在这里我制订了一条rule"[rule1:(?x http://www.owl-ontologies.com/Expert.owl#research ?y) " +
"(?y http://www.owl-ontologies.com/Expert.owl#associate ?z) " +
"->(?x http://www.owl-ontologies.com/Expert.owl#familiar_with ?z)]";
x p1 y ,y p2 z, --->x p3 z设置好这条规则之后，本体中建立了一个实例：
<Expert rdf:ID="ChenJianer">
<country_is>
<Country rdf:ID="America"/>
</country_is>
<graduate_from>
<College rdf:ID="Central_South_University"/>
</graduate_from>
<gender rdf:datatype="http://www.w3.org/2001/XMLSchema#boolean">true</gender>
<people_is>
<People rdf:ID="Chinese"/>
</people_is>
<research>
<Profession rdf:ID="Bioinformatics">
<be_researched rdf:resource="#ChenJianer"/>
<associat>
<Computer_Science_and_Technology rdf:ID="Computer_Software_and_Theory">
<be_associated rdf:resource="#Bioinformatics"/>
<be_associated>
<Profession rdf:ID="Computer_Optimization_Algorithm">
<associat rdf:resource="#Computer_Software_and_Theory"/>
<be_researched rdf:resource="#ChenJianer"/>
</Profession>
</be_associated>
<be_familiar_with rdf:resource="#ChenJianer"/>
</Computer_Science_and_Technology>
</associat>
</Profession>
</research>
<research rdf:resource="#Computer_Optimization_Algorithm"/>
<E_mail xml:lang="en">shalen2008@sina.com</E_mail>
<Technical_level xml:lang="en">1</Technical_level>
<Graduation_time rdf:datatype="http://www.w3.org/2001/XMLSchema#date">2008-03-04</Graduation_time>
<familiar_with rdf:resource="#Computer_Software_and_Theor"/>这里已经有了familar_with了，经过sparql查询之后就输出它的值： Computer_Software_and_Theor
<workplace xml:lang="en">Washington University</workplace>
<mother_language_is rdf:resource="#english"/>
<name xml:lang="en">ChenJianer</name>
<work_tel xml:lang="en">882555121</work_tel>
<home_address xml:lang="en">NewYork001</home_address>
<ID_card xml:lang="en">4216633322656</ID_card>
<is_Academician rdf:datatype="http://www.w3.org/2001/XMLSchema#boolean">true</is_Academician>
<birthday rdf:datatype="http://www.w3.org/2001/XMLSchema#date">2008-03-23</birthday>
</Expert>
在上面标红的位置，如果不使用rule，
用sparql：PREFIX Expert:<http://www.owl-ontologies.com/Expert.owl#> " +
"SELECT ?expert ?subject " +
"WHERE {?expert Expert:familiar_with ?subject} ";
一样可以得到结果
现在很明显：expert:ChenJianer research Bioinformatics,
Bioinformatics associate Computer_Software_and_Theory(注意代码中标红的地方)
那么根据规则："[rule1:(?x http://www.owl-ontologies.com/Expert.owl#research ?y) " +
"(?y http://www.owl-ontologies.com/Expert.owl#associate ?z) " +
"->(?x http://www.owl-ontologies.com/Expert.owl#familiar_with ?z)]";
expert:ChenJianer familiar_with Computer_Software_and_Theory
但是为什么我把这条规则去掉以后，不使用rule，和jena的推理引擎，直接使用sparql查询本体，可以得到一样的结果，我自己认为是
<familiar_with rdf:resource="#Computer_Software_and_Theory"/>（在代码中红的地方）这条代码的问题，请问怎么让这条rule，对输出的结果产生影响啊，就是说使得带有rule，和不带有rule得到的结果不同。请指教
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2009/4/24 20:14:00
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rule试验遇到问题
