处理java.lang.VerifyError

Question

I have written a Java Program using Lucene in Eclipse Juno. Whenever I try to run it, it is giving the following errors:

Exception in thread "main" java.lang.VerifyError: Cannot inherit from final class

at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
at parser.BuildMainIndex.setUp(BuildMainIndex.java:339)
at parser.luceneDemo.main(luceneDemo.java:10)

and source of the error ie the line in BuildManinIndex.java is:

        doc.add(new IntField("startTime1",startTime1,Field.Store.YES));

Here startTime1 is a field in document to be indexed. I was earlier using Lucene 3.6.0 and now I am using Lucene 4.3.0. I have not imported any thing from java.net.URL. I have no clue of the possible cause of this error. Please help.

This following short program I have written.

writer=new IndexWriter(directory,new StandardAnalyzer(Version.LUCENE_CURRENT),IndexWriter.MaxFieldLength.UNLIMITED);

Document doc=new Document();
doc.add(new Field("title","XYZ",Field.Store.YES,Field.Index.ANALYZED));
doc.add(new Field("address","ABC Road",Field.Store.YES,Field.Index.ANALYZED));
doc.add(new Field("city","Mumbai",Field.Store.YES,Field.Index.ANALYZED));
doc.add(new IntField("startTime1",900,Field.Store.YES));
doc.add(new IntField("finishTime1",1000,Field.Store.YES));
doc.add(new IntField("startTime2",9999,Field.Store.YES));
doc.add(new IntField("finishTime2",9999,Field.Store.YES));

writer.addDocument(doc);
writer.close();

Answer 1

The error message is a bit confusing because you are not inheriting the IntField class, you are creating an instance of it, right?

doc.add(new IntField("startTime1", startTime1, Field.Store.YES));

The problem is in the first part of that statement doc.add(..) . There was a change to the Document class between Lucene versions 3.6.0 and 4.x - add(..) in 3.6 is accepting Fieldable ( class API ), and in 4.1.0 is accepting IndexableField ( class API ).

Useful article on the VerifyError . Or this StackOverflow answer .

Also, there is no IntField in Lucene 3.6.0, ie the class is from Apache Solr ( class API ) but there is one in Lucene 4.1.0. You are probably using the 3.6 version of IntField which is not the same as Lucene's - please check your import statements and your classpath.

UPDATE

Joy, the easiest solution for you is to remove the old Lucene JAR files from /home/abhishek/mtp/stage-2/software/apache-tomcat-7.0.37/lib and put the new ones, and Refresh the project in Eclipse.

My advice for you is to switch to Apache Maven for dependency management (there is a Maven plug-in for Eclipse). In Eclipse you create a "New Maven Project" and add the dependencies to pom.xml file - an example for Lucene . This way you don't have to copy any JAR files into your project or Tomcat.

Good luck.