Java Program to Extract Content from a Java's .class File

// Java program to extract the
// contents of Java class file
// format

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

// importing Apache Tika libraries
import org.apache.tika.exception.TikaException;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.parser.AutoDetectParser;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.parser.Parser;
import org.apache.tika.sax.BodyContentHandler;

import org.xml.sax.SAXException;

public class ParserExtraction {

    public static void main(final String[] args)
        throws IOException, SAXException, TikaException
    {
        // create a File object
        File f = new File("AddTwoNumbers.java");

        // parse method parameters
        Parser parser = new AutoDetectParser();

        // instantiate BodyContentHandle
        BodyContentHandler handler
            = new BodyContentHandler();

        // Creates the Metadata object
        Metadata metadata = new Metadata();

        FileInputStream inputstream
            = new FileInputStream(f);

        // creates a parse context object
        ParseContext context = new ParseContext();

        // parsing the file
        parser.parse(inputstream, handler, metadata,
                     context);
          
          // display the file content
        System.out.println("File content : "
                           + Handler.toString());
    }
}