我需要针对一个使用 fuseki+mysql 作为三重存储的旧数据库解决方案来测试一个特定的数据库解决方案。基本上,我需要做的就是使用 SPARQL 对我之前创建的数据库进行一些查询。问题是我似乎无法配置 fuseki 给我这个数据库的端点。我已经使用普通的标准 java 编码(不使用 Jena SDB 组件的 JDBC)创建了数据库。我使用的mysql版本是:
mysql Ver 14.14 Distrib 5.5.37, for debian-linux-gnu (x86_64) using readline 6.3
基本上我有一个我无法解决的 ClassNotFoundException。这里是异常的详细信息:
com.hp.hpl.jena.shared.JenaException: java.lang.ClassNotFoundException: net.rootdev.fusekisdbconnect.SDBConnect
at com.hp.hpl.jena.assembler.AssemblerHelp.loadClassNamedBy(AssemblerHelp.java:145)
at com.hp.hpl.jena.assembler.AssemblerHelp.loadArbitraryClass(AssemblerHelp.java:129)
at com.hp.hpl.jena.assembler.AssemblerHelp.loadArbitraryClasses(AssemblerHelp.java:93)
at com.hp.hpl.jena.assembler.assemblers.AssemblerGroup$ExpandingAssemblerGroup.loadClasses(AssemblerGroup.java:86)
at com.hp.hpl.jena.assembler.assemblers.AssemblerGroup$ExpandingAssemblerGroup.open(AssemblerGroup.java:79)
at com.hp.hpl.jena.assembler.assemblers.AssemblerBase.open(AssemblerBase.java:52)
at com.hp.hpl.jena.assembler.assemblers.AssemblerBase.open(AssemblerBase.java:48)
at org.apache.jena.fuseki.server.FusekiConfig.processService(FusekiConfig.java:241)
at org.apache.jena.fuseki.server.FusekiConfig.configure(FusekiConfig.java:149)
at org.apache.jena.fuseki.FusekiCmd.exec(FusekiCmd.java:364)
at arq.cmdline.CmdMain.mainMethod(CmdMain.java:97)
at arq.cmdline.CmdMain.mainRun(CmdMain.java:59)
at arq.cmdline.CmdMain.mainRun(CmdMain.java:46)
at org.apache.jena.fuseki.FusekiCmd.main(FusekiCmd.java:101)
Caused by: java.lang.ClassNotFoundException: net.rootdev.fusekisdbconnect.SDBConnect
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:190)
at com.hp.hpl.jena.assembler.AssemblerHelp.loadClassNamedBy(AssemblerHelp.java:144)
... 13 more
fuseki 的调用将所需的库添加到类路径中(我将它们存储在 fuseki 主目录内的 lib 目录中):
java -cp lib/arq-2.8.8.jar:lib/arq-2.8.9-SNAPSHOT.jar:lib/jena-iri-0.9.0-incubating.jar:lib/mysql-connector-java-5.1.19.jar:lib/ReconnectingSDB-0.1-SNAPSHOT.jar:lib/sdb-1.3.4.jar -jar fuseki-server.jar --config=fuseki-mysql.ttl
我的配置文件:
# Licensed under the terms of http://www.apache.org/licenses/LICENSE-2.0
@prefix : <#> .
@prefix fuseki: <http://jena.apache.org/fuseki#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix tdb: <http://jena.hpl.hp.com/2008/tdb#> .
@prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> .
@prefix jumble: <http://rootdev.net/vocab/jumble#> .
@prefix sdb: <http://jena.hpl.hp.com/2007/sdb#> .
[] rdf:type fuseki:Server ;
# Timeout - server-wide default: milliseconds.
# Format 1: "1000" -- 1 second timeout
# Format 2: "10000,60000" -- 10s timeout to first result, then 60s timeout to for rest of query.
# See java doc for ARQ.queryTimeout
ja:context [ ja:cxtName "arq:queryTimeout" ; ja:cxtValue "10000,60000" ] ;
fuseki:services (
<#service_MySQL_read_only>
) .
# SDB
[] ja:loadClass "net.rootdev.fusekisdbconnect.SDBConnect" .
jumble:SDBConnect rdfs:subClassOf ja:RDFDataset .
<#service_MySQL_read_only> rdf:type fuseki:Service ;
rdfs:label "UF MySQL Service (R)" ;
fuseki:name "MySQL" ;
fuseki:serviceQuery "query" ;
fuseki:serviceQuery "sparql" ;
fuseki:serviceUpdate "update" ;
fuseki:serviceUpload "upload" ;
fuseki:serviceReadWriteGraphStore "data" ;
# A separate read-only graph store endpoint:
fuseki:serviceReadGraphStore "get" ;
fuseki:dataset <#ufmysql_dataset_read> ;
#fuseki:dataset <#MySQLStore> ;
.
<#ufmysql_dataset_read> rdf:type sdb:DatasetStore ;
sdb:store <#MySQLStore>
.
<#MySQLStore> rdf:type jumble:SDBConnect;
rdfs:label "UF MySQL SDB Store";
sdb:layout "layout2";
sdb:connection
[ rdf:type sdb:SDBConnection;
sdb:sdbHost "localhost";
sdb:sdbType "MySQL";
sdb:sdbName "EA_db_test";
sdb:sdbUser "*****";
sdb:sdbPassword "*****";
sdb:driver "com.mysql.jdbc.Driver";
]
.
如果我代替 ja:loadClass "net.rootdev.fusekisdbconnect.SDBConnect" (我认为有点旧) ja:loadClass "com.hp.hpl.jena.sdb.SDB" 我得到同样的例外但有 SDB 类
com.hp.hpl.jena.shared.JenaException: java.lang.ClassNotFoundException: com.hp.hpl.jena.sdb.SDB
我在 fuseki 的 lib 文件夹中的 jar 列表是:
2247124 mag 12 2012 arq-2.8.8.jar
2259436 mag 12 2012 arq-2.8.9-SNAPSHOT.jar
154157 mag 12 2012 jena-iri-0.9.0-incubating.jar
801912 mag 12 2012 mysql-connector-java-5.1.19.jar
6657 mag 12 2012 ReconnectingSDB-0.1-SNAPSHOT.jar
529092 mag 12 2012 sdb-1.3.4.jar
我的 FUSEKI 版本:
Jena: VERSION: 2.7.1-incubating-SNAPSHOT
Jena: BUILD_DATE: 20120426-0201
ARQ: VERSION: 2.9.1-incubating-SNAPSHOT
ARQ: BUILD_DATE: 20120430-1956
TDB: VERSION: 0.9.1-incubating-SNAPSHOT
TDB: BUILD_DATE: 20120430-2052
Fuseki: VERSION: 0.2.2-incubating-SNAPSHOT
Fuseki: BUILD_DATE: 20120501-1232
我应该使用任何特定的 jar 版本组合吗?关于我可以在哪里找到缺少的 jar 的任何指针(如果缺少某些东西或者我需要不同的版本)。还是我只是对配置文件有误,我应该使用不同的东西?
谢谢帮助