Java中的SPARQL查询REGEX边界返回空 [英] SPARQL query REGEX boundary in java returns empty

问题描述

我是SPARQL和Jena的新手.在这里，我使用的是Jena 2.13版.我想从Java Web应用程序使用REGEX边界(\b)执行SPARQL查询.我正在使用REGEX边界来匹配并找到确切的单词.

i'm new in SPARQL and Jena. Here i'm using Jena version 2.13. I would like to perform a SPARQL query from java web application with REGEX boundary (\b). I'm using REGEX boundary to match and find exact word.

我也在protege上运行相同的SPARQL查询.

I'm running the same SPARQL query on protege too.

这是我在Java中的SPARQL查询:

Here my SPARQL query in java :

                "PREFIX foaf: <http://xmlns.com/foaf/0.1/> "
                + "PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> "
                + "PREFIX owl: <http://www.w3.org/2002/07/owl#> "
                + "PREFIX xsd: <http://www.w3.org/2001/XMLSchema#> "
                + "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> "
                + "PREFIX : <" + CROSS_NS + "> "
                + "SELECT ((?FoodAndBeveragesRecipes) AS ?Resep)((?FoodAndBeverages) AS ?a) "
                + "WHERE{ ?FoodAndBeveragesRecipes :IngR ?_IngR."
                + " ?_IngR :HasIngredients ?FoodAndBeverages;"
                + ":UnitValue ?Value;"
                + " :MeasurementUnit ?Measurements;"
                + " :Ing_Type ?IngType." 
                + "FILTER regex(str(?FoodAndBeverages), \"\\b" + recipe + "\\b\")}"
                + " ORDER BY ?FoodAndBeveragesRecipes";

recipe是用于存储用户输入的String variabel，它作为参数接收.

recipe is String variabel to store user input, it's received as a parameter.

当我执行查询时，Jena返回一个空集(甚至没有null指针异常)，而Protégé返回/查找正确的结果. 我不知道问题出在REGEX代码还是什么.

When i perform the query, Jena returns an empty set (not even null pointer exception) while Protégé return/find the correct results. I don't know if the problem is with the REGEX code or what.

我想知道为什么我的REGEX无法正常工作?有人可以帮我吗?

I was wondering why my REGEX is not working correctly ? could anyone help me?

谢谢.

推荐答案

您需要\\\\W-是，4. Java进入一个级别将\\W放入SPARQL，下一级别是将SPARQL字符串精确保留为\W.

You need \\\\W - yes, 4 . One level goes for Java to get \\W into SPARQL, the next level is the SPARQL string to leave exactly \W.

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