在SPARQL查询中的查询字符串外部使用声明的变量-使用JSP和Java Servlet

时间:2018-07-04 03:43:07

标签: java nlp sparql rdf jena

我有2个jsp页面。在索引页面中,我选择一个下拉值,并将所选值作为url参数传递给SearchResults页面。

http://localhost:8080/SearchResults.jsp?jobCat=InformationTechnology

我正在捕获使用以下代码传递的参数InformationTechnology。查询应在表格中显示所选值的结果。 (我正在选择职位类别,结果应显示所选职位类别下的候选人)

String jobCategory = request.getParameter("jobCat");

下面是我的查询

String queryString =
"Select ?a ?b"+
" Where { ...."+
" Filter (?a = "+ jobCategory  +")"+// jobCategory is the String variable 
" }";

但是我收到ParseException错误。

com.hp.hpl.jena.query.QueryParseException: Encountered " "in" "In "" at line 
1, column 559.
Was expecting one of:
<IRIref> ...
<PNAME_NS> ...
<PNAME_LN> ...
<VAR1> ...
<VAR2> ...
"exists" ...
"not" ...
"count" ...
"min" ...
"max" ...
"sum" ...
"avg" ...
"sample" ...
"group_concat" ...
"bound" ...
"coalesce" ...
"if" ...
"bnode" ...
"iri" ...
"uri" ...
"str" ...
"strlang" ...
"strdt" ...
"datatype" ...
"lang" ...
"langmatches" ...
"isURI" ...
"isIRI" ...
"isBlank" ...
"isLiteral" ...
"isNumeric" ...
"regex" ...
"sameTerm" ...
"RAND" ...
"ABS" ...
"CEIL" ...
"FLOOR" ...
"ROUND" ...
"CONCAT" ...
"SUBSTR" ...
"STRLEN" ...
"UCASE" ...
"LCASE" ...
"ENCODE_FOR_URI" ...
"CONTAINS" ...
"strSTARTS" ...
"strENDS" ...
"YEAR" ...
"MONTH" ...
"DAY" ...
"HOURS" ...
"MINUTES" ...
"SECONDS" ...
"TIMEZONE" ...
"TZ" ...
"NOW" ...
"MD5" ...
"SHA1" ...
"SHA224" ...
"SHA256" ...
"SHA384" ...
"SHA512" ...
"true" ...
"false" ...
<INTEGER> ...
<DECIMAL> ...
<DOUBLE> ...
<INTEGER_POSITIVE> ...
<DECIMAL_POSITIVE> ...
<DOUBLE_POSITIVE> ...
<INTEGER_NEGATIVE> ...
<DECIMAL_NEGATIVE> ...
<DOUBLE_NEGATIVE> ...
<STRING_LITERAL1> ...
<STRING_LITERAL2> ...
<STRING_LITERAL_LONG1> ...
<STRING_LITERAL_LONG2> ...
"(" ...
"!" ...
"+" ...
"-" ...

是否有另一种方法可以像类似情况一样在SPARQL查询中使用字符串变量。预先感谢

2 个答案:

答案 0 :(得分:1)

我认为jobCategory是文字/标签?简单直接问标签。

String queryString =
"Select ?a ?b"+
" Where { <uri> <uri>\""  + jobCategory +"\"}";

我假设这是查询的URI。

String queryString =
"Select ?a ?b"+
" Where { <uri> <uri> <" + jobCategory+ ">}";

答案 1 :(得分:1)

我有解决此问题的方法。 我用regex来获得结果

"filter(regex(?a, \"" + jobCategory + "\"))"