import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import org.apache.tika.exception.TikaException;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.parser.asm.ClassParser;
import org.apache.tika.sax.BodyContentHandler;

import org.xml.sax.SAXException;

public class JavaClassParse {

   public static void main(final String[] args) throws IOException,SAXException, TikaException {

      //detecting the file type
      BodyContentHandler handler = new BodyContentHandler();
      Metadata metadata = new Metadata();
      FileInputStream inputstream = new FileInputStream(new File("Example.class"));
      ParseContext pcontext = new ParseContext();

      //Html parser
      ClassParser  ClassParser = new  ClassParser();
      ClassParser.parse(inputstream, handler, metadata,pcontext);
      System.out.println("Contents of the document:" + handler.toString());
      System.out.println("Metadata of the document:");
      String[] metadataNames = metadata.names();
      
      for(String name : metadataNames) {                
         System.out.println(name + " :  " + metadata.get(name));  
      }
   }
}

javac JavaClassParse.java
java JavaClassParse 

Contents of the document:

package tutorialspoint.tika.examples;
public synchronized class Example {
   public void Example();
   public static void main(String[]);
}

Metadata of the document:

title: Example
resourceName: Example.class
dc:title: Example