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我想使用SPARQL查詢鏈接電影數據庫的本地版本。該文件採用N-Triples格式，其大小約爲450mb。我正在使用servlet來實現。現在，當我通過查詢，大約需要超過五分鐘的servlet來處理它，並在年底，我得到以下異常：無法查詢鏈接電影數據庫的本地版本
type Exception report
message
description The server encountered an internal error() that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Servlet execution threw an exception
root cause
java.lang.OutOfMemoryError: Java heap space
java.util.Arrays.copyOfRange(Arrays.java:3209)
java.lang.String.<init>(String.java:215)
java.lang.StringBuilder.toString(StringBuilder.java:430)
org.openjena.riot.tokens.TokenizerText.allBetween(TokenizerText.java:732)
org.openjena.riot.tokens.TokenizerText.parseToken(TokenizerText.java:152)
org.openjena.riot.tokens.TokenizerText.hasNext(TokenizerText.java:69)
org.openjena.atlas.iterator.PeekIterator.fill(PeekIterator.java:37)
org.openjena.atlas.iterator.PeekIterator.next(PeekIterator.java:77)
org.openjena.riot.lang.LangBase.nextToken(LangBase.java:145)
org.openjena.riot.lang.LangNTriples.parseOne(LangNTriples.java:59)
org.openjena.riot.lang.LangNTriples.parseOne(LangNTriples.java:21)
org.openjena.riot.lang.LangNTuple.runParser(LangNTuple.java:58)
org.openjena.riot.lang.LangBase.parse(LangBase.java:75)
org.openjena.riot.system.JenaReaderNTriples2.readWorker(JenaReaderNTriples2.java:28)
org.openjena.riot.system.JenaReaderRIOT.readImpl(JenaReaderRIOT.java:124)
org.openjena.riot.system.JenaReaderRIOT.read(JenaReaderRIOT.java:79)
com.hp.hpl.jena.rdf.model.impl.ModelCom.read(ModelCom.java:226)
com.hp.hpl.jena.util.FileManager.readModelWorker(FileManager.java:395)
com.hp.hpl.jena.util.FileManager.loadModelWorker(FileManager.java:299)
com.hp.hpl.jena.util.FileManager.loadModel(FileManager.java:250)
ServletExample.runQuery(ServletExample.java:92)
ServletExample.doGet(ServletExample.java:62)
javax.servlet.http.HttpServlet.service(HttpServlet.java:627)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.31 logs.
我的代碼是：
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.*;
import com.hp.hpl.jena.query.*;
import com.hp.hpl.jena.rdf.model.*;
import com.hp.hpl.jena.util.FileManager;
public class ServletExample
extends HttpServlet
{
/***********************************/
/* Constants */
/***********************************/
private static final long serialVersionUID = 1L;
public static final String SPARQL_ENDPOINT = "http://data.linkedmdb.org/sparql";
public static final String QUERY ="PREFIX m: <http://data.linkedmdb.org/resource/movie/>"
+"SELECT DISTINCT ?actorName WHERE {"+
"?dir1 m:director_name \"Sofia Coppola\"."+
"?dir2 m:director_name \"Francis Ford Coppola\"."+
"?dir1film m:director ?dir1;"+
"m:actor ?actor."+
"?dir2film m:director ?dir2;"+
"m:actor ?actor."+
"?actor m:actor_name ?actorName."+
"}";
/*"PREFIX m: <http://data.linkedmdb.org/resource/movie/>\n" +
"SELECT DISTINCT ?actorName WHERE {\n" +
" ?dir1 m:director_name %dir_name_1%.\n" +
" ?dir2 m:director_name %dir_name_2%.\n" +
" ?dir1film m:director ?dir1;\n" +
" m:actor ?actor.\n" +
" ?dir2film m:director ?dir2;\n" +
" m:actor ?actor.\n" +
" ?actor m:actor_name ?actorName.\n" +
"}\n" +
"";*/
private static final String HEADER = "<html>\n" +
" <head>\n" +
" <title>results</title>\n" +
" <link href=\"simple.css\" type=\"text/css\" rel=\"stylesheet\" />\n" +
" </head>\n" +
" <body>\n" +
"";
private static final String FOOTER = "</body></html>";
/**
* Respond to HTTP GET request. Will need to be mounted against some URL
* pattern in web.xml
*/
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
String dir1 = req.getParameter("dir1");//"Sofia";
String dir2 = req.getParameter("dir2");//"Francis Ford Coppola";
//String dir1 = "Sofia";
//String dir2 = "Francis Ford Coppola";
if (dir1 == null || dir2 == null || dir1.isEmpty() || dir2.isEmpty()) {
noInput(resp);
}
else {
runQuery(resp, dir1, dir2);
}
}
protected void noInput(HttpServletResponse resp)
throws IOException
{
header(resp);
resp.getWriter().println("<p>Please select director names as query params <code>dir1</code> and <code>dir2</code></p>");
footer(resp);
}
protected void footer(HttpServletResponse resp) throws IOException {
resp.getWriter().println(FOOTER);
}
protected void header(HttpServletResponse resp) throws IOException {
resp.getWriter().println(HEADER);
}
protected void runQuery(HttpServletResponse resp, String dir1, String dir2)
throws IOException
{
PrintWriter out = resp.getWriter();
// Set up the query
// String q = QUERY.replace("%dir_name_1%", "\"" + dir1 + "\"")
// .replace("%dir_name_2%", "\"" + dir2 + "\"");
String q=QUERY;
Query query = QueryFactory.create(q) ;
Model model = FileManager.get().loadModel("e:\\applications\\linkedmdb-18-05-2009-dump\\dump.nt");
// QueryExecution qexec = QueryExecutionFactory.sparqlService(SPARQL_ENDPOINT, query);
//com.hp.hpl.jena.query.Query query = QueryFactory.create(QUERY);
QueryExecution qexec = QueryExecutionFactory.create(query, model);
// perform the query
ResultSet results = qexec.execSelect();
// generate the output
header(resp);
if (!results.hasNext()) {
out.println("<p>No results, sorry.</p>");
}
else {
out.println("<h1>Results</h1>");
while (results.hasNext()) {
QuerySolution qs = results.next();
String actorName = qs.getLiteral("actorName").getLexicalForm();
out.println(String.format("<div>Actor named: %s</div>", actorName));
}
}
footer(resp);
}
}
有有什麼辦法來解決這個異常？
你能準確地知道它在日食helios中的位置嗎？我無法找到它 – ProgramME 2011-04-09 14:02:45
如何啓動應用程序服務器？一個地方可能是運行 - >運行配置 - > VM參數。 – 2011-04-09 14:04:29
的是，我得到相同exception.i加入你右擊input.html說（文件開始用的applcation，然後運行配置和VM arguments.i我張貼的代碼 – ProgramME 2011-04-09 14:19:01