Type Exception Report
Message Unexpected error making the query: org.apache.http.conn.HttpHostConnectException: Connection to http://shetland.informatik.uni-freiburg.de:8890 refused
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
HttpException: org.apache.http.conn.HttpHostConnectException: Connection to http://shetland.informatik.uni-freiburg.de:8890 refused: Unexpected error making the query: org.apache.http.conn.HttpHostConnectException: Connection to http://shetland.informatik.uni-freiburg.de:8890 refused com.hp.hpl.jena.sparql.engine.http.HttpQuery.rewrap(HttpQuery.java:417) com.hp.hpl.jena.sparql.engine.http.HttpQuery.execGet(HttpQuery.java:358) com.hp.hpl.jena.sparql.engine.http.HttpQuery.exec(HttpQuery.java:295) com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execModel(QueryEngineHTTP.java:414) com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execConstruct(QueryEngineHTTP.java:387) com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execConstruct(QueryEngineHTTP.java:382) servlets.MAGWrapper.queryAndAnswerForSubject(MAGWrapper.java:144) servlets.MAGWrapper.doPost(MAGWrapper.java:95) servlets.MAGWrapper.doGet(MAGWrapper.java:52) javax.servlet.http.HttpServlet.service(HttpServlet.java:635) javax.servlet.http.HttpServlet.service(HttpServlet.java:742) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause
org.apache.http.conn.HttpHostConnectException: Connection to http://shetland.informatik.uni-freiburg.de:8890 refused org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:190) org.apache.http.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:294) org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:643) org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:479) org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906) org.apache.http.impl.client.DecompressingHttpClient.execute(DecompressingHttpClient.java:137) org.apache.http.impl.client.DecompressingHttpClient.execute(DecompressingHttpClient.java:118) org.apache.jena.riot.web.HttpOp.exec(HttpOp.java:1108) org.apache.jena.riot.web.HttpOp.execHttpGet(HttpOp.java:385) org.apache.jena.riot.web.HttpOp.execHttpGet(HttpOp.java:447) com.hp.hpl.jena.sparql.engine.http.HttpQuery.execGet(HttpQuery.java:346) com.hp.hpl.jena.sparql.engine.http.HttpQuery.exec(HttpQuery.java:295) com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execModel(QueryEngineHTTP.java:414) com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execConstruct(QueryEngineHTTP.java:387) com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execConstruct(QueryEngineHTTP.java:382) servlets.MAGWrapper.queryAndAnswerForSubject(MAGWrapper.java:144) servlets.MAGWrapper.doPost(MAGWrapper.java:95) servlets.MAGWrapper.doGet(MAGWrapper.java:52) javax.servlet.http.HttpServlet.service(HttpServlet.java:635) javax.servlet.http.HttpServlet.service(HttpServlet.java:742) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause
java.net.ConnectException: Connection refused (Connection refused) java.base/java.net.PlainSocketImpl.socketConnect(Native Method) java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399) java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242) java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224) java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:403) java.base/java.net.Socket.connect(Socket.java:591) org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:127) org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:180) org.apache.http.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:294) org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:643) org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:479) org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906) org.apache.http.impl.client.DecompressingHttpClient.execute(DecompressingHttpClient.java:137) org.apache.http.impl.client.DecompressingHttpClient.execute(DecompressingHttpClient.java:118) org.apache.jena.riot.web.HttpOp.exec(HttpOp.java:1108) org.apache.jena.riot.web.HttpOp.execHttpGet(HttpOp.java:385) org.apache.jena.riot.web.HttpOp.execHttpGet(HttpOp.java:447) com.hp.hpl.jena.sparql.engine.http.HttpQuery.execGet(HttpQuery.java:346) com.hp.hpl.jena.sparql.engine.http.HttpQuery.exec(HttpQuery.java:295) com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execModel(QueryEngineHTTP.java:414) com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execConstruct(QueryEngineHTTP.java:387) com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execConstruct(QueryEngineHTTP.java:382) servlets.MAGWrapper.queryAndAnswerForSubject(MAGWrapper.java:144) servlets.MAGWrapper.doPost(MAGWrapper.java:95) servlets.MAGWrapper.doGet(MAGWrapper.java:52) javax.servlet.http.HttpServlet.service(HttpServlet.java:635) javax.servlet.http.HttpServlet.service(HttpServlet.java:742) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Note The full stack trace of the root cause is available in the server logs.