HTTP Status 500 - javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.servlet.jsp.JspException: java.lang.RuntimeException: Comparison method violates its general contract! ([1:42])

type Exception report

message javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.servlet.jsp.JspException: java.lang.RuntimeException: Comparison method violates its general contract! ([1:42])

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.servlet.jsp.JspException: java.lang.RuntimeException: Comparison method violates its general contract! ([1:42])
	org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:555)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:461)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:401)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:345)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

root cause

javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.servlet.jsp.JspException: java.lang.RuntimeException: Comparison method violates its general contract! ([1:42])
	org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:906)
	org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:838)
	org.apache.jsp.list_002dforums_jsp._jspService(list_002dforums_jsp.java:261)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:401)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:345)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

root cause

javax.servlet.jsp.JspException: java.lang.RuntimeException: Comparison method violates its general contract! ([1:42])
	org.apache.jsp.tag.web.get.lastForumMessage_tag.doTag(lastForumMessage_tag.java:154)
	org.apache.jsp.list_002dforums_jsp$Helper.invoke0(list_002dforums_jsp.java:749)
	org.apache.jsp.list_002dforums_jsp$Helper.invoke(list_002dforums_jsp.java:912)
	org.apache.jsp.tag.web.base_tag.doTag(base_tag.java:278)
	org.apache.jsp.list_002dforums_jsp._jspService(list_002dforums_jsp.java:248)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:401)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:345)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

root cause

java.lang.RuntimeException: Comparison method violates its general contract! ([1:42])
	java.util.TimSort.mergeLo(TimSort.java:777)
	java.util.TimSort.mergeAt(TimSort.java:514)
	java.util.TimSort.mergeCollapse(TimSort.java:441)
	java.util.TimSort.sort(TimSort.java:245)
	java.util.Arrays.sort(Arrays.java:1512)
	java.util.ArrayList.sort(ArrayList.java:1462)
	java.util.Collections.sort(Collections.java:175)
	org.ontobox.libretto.collection.SimpleCol.sort(SimpleCol.java:314)
	org.ontobox.libretto.collection.OntCC.sort(OntCC.java:73)
	org.ontobox.libretto.Interp.calcPath(Interp.java:2761)
	org.ontobox.libretto.Interp.computePath(Interp.java:113)
	org.ontobox.libretto.Handler.getProgram(Handler.java:570)
	org.ontobox.libretto.Handler.getProgram(Handler.java:425)
	org.ontobox.libretto.Handler.execute(Handler.java:232)
	org.ontobox.libretto.Handler.execute(Handler.java:203)
	org.ontobox.box.query.QContext.execute(QContext.java:205)
	org.ontobox.box.base.BaseBoxWorker.qValues(BaseBoxWorker.java:679)
	org.ontobox.box.base.BaseBoxWorker.qMap(BaseBoxWorker.java:703)
	com.teacode.forum.model.Forum.getLastForumMessage(Forum.java:162)
	org.apache.jsp.tag.web.get.lastForumMessage_tag.doTag(lastForumMessage_tag.java:143)
	org.apache.jsp.list_002dforums_jsp$Helper.invoke0(list_002dforums_jsp.java:749)
	org.apache.jsp.list_002dforums_jsp$Helper.invoke(list_002dforums_jsp.java:912)
	org.apache.jsp.tag.web.base_tag.doTag(base_tag.java:278)
	org.apache.jsp.list_002dforums_jsp._jspService(list_002dforums_jsp.java:248)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:401)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:345)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

note The full stack trace of the root cause is available in the Apache Tomcat/8.0.32 (Ubuntu) logs.


Apache Tomcat/8.0.32 (Ubuntu)