2 Replies Latest reply on Sep 29, 2007 7:09 AM by Henry Story

    Inconsistent stack height 0 != 1

    Henry Story Newbie

      I am getting a weird exception when I add code to the toString method of the following class.
      This is code I am working on https://sommer.dev.java.net project.
      My javassist byte code rewritten classes otherwise work well (though I am only now starting to test them in more serious ways).


      package net.java.dev.sommer.doap.ont;
      
      import java.io.File;
      import java.net.URL;
      import java.util.Collection;
      import net.java.rdf.annotations.rdf;
      import net.java.dev.sommer.doap.CheckoutHandler;
      import static net.java.dev.sommer.doap.ont.DoapProject.doap;
      
      /**
       *
       * @author hjs
       */
      @rdf(doap+"Repository")
      public class Repository {
      
       @rdf(doap+"location") private URL location;
       @rdf(doap+"browse") private Collection<URL> browse;
       @rdf(doap+"anon-root") private String anonRoot;
       @rdf(doap+"name") private String name;
      
       public CheckoutHandler checkout(File destination) {
       throw new UnsupportedOperationException("Not yet implemented");
       }
      
       public String getType() {
       return "unknown";
       }
      
       public URL getLocation() {
       return location;
       }
      
       public Collection<URL> getBrowse() {
       return browse;
       }
      
       public String getAnonRoot() {
       return anonRoot;
       }
      
       @Override
       public String toString() {
       if (name != null) return getType()+" type "+name;
      // if (location != null) return getType()+" type at "+location.getPath();
       return getType()+" type with no name";
       }
      
      
      }


      The stack trace is the following

      java.lang.VerifyError: (class: net/java/dev/sommer/doap/ont/Repository, method: toString signature: ()Ljava/lang/String;) Inconsistent stack height 0 != 1
       at java.lang.Class.getDeclaredConstructors0(Native Method)
       at java.lang.Class.privateGetDeclaredConstructors(Class.java:2328)
       at java.lang.Class.getConstructor0(Class.java:2640)
       at java.lang.Class.getConstructor(Class.java:1629)
       at net.java.rdf.sommer.SesameMapper.map(SesameMapper.java:989)
       at net.java.rdf.sommer.SesameMapper.getCollection(SesameMapper.java:1220)
       at net.java.rdf.sommer.util.RDFCollection.getCurrentCollection(RDFCollection.java:113)
       at net.java.rdf.sommer.util.RDFCollection.isEmpty(RDFCollection.java:121)
       at net.java.dev.sommer.doap.DoapDisplayForm.htmlForProject(DoapDisplayForm.java:222)
       at net.java.dev.sommer.doap.DoapDisplayForm.<init>(DoapDisplayForm.java:48)
       at net.java.dev.sommer.doap.DoapFetcher.useTheDoapFile(DoapFetcher.java:226)
       at net.java.dev.sommer.doap.DoapFetcher.run(DoapFetcher.java:214)
       at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
       at java.awt.EventQueue.dispatchEvent(EventQueue.java:461)
      [catch] at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:269)
       at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
       at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:184)
       at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:176)
       at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
      


      perhaps I can send the byte code too. I am not sure where I should look to resolve the problem. If I remove the
      code from the toString() everything works fine.

      I can dissasemble the byte code with jad, and javap seems to have to trouble with it either.