如何使用java從.class檔案中提取內容?

在Java程式設計中，如何使用java從.class文件中提取內容？

專案的目錄結構如下 -

Tika的工具包可從以下網址下載：http://tika.apache.org/download.html ，只下載：tika-app-1.16.jar 和 tika-server-1.16.jar 。

以下是使用java從.class文件中提取內容的程式 -

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

      //detecting the file type
      BodyContentHandler handler = new BodyContentHandler();

      Metadata metadata = new Metadata();
      FileInputStream inputstream = new FileInputStream(new File(
         "bin/ExtractContentFromJavaClass.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));   
      }
   }
}

執行上面範例程式碼，得到以下結果 -

Contents of the document:public synchronized class ExtractContentFromJavaClass {
    public void ExtractContentFromJavaClass();
    public static void main(String[]) throws java.io.IOException, org.xml.sax.SAXException, org.apache.tika.exception.TikaException;
}

Metadata of the document:
dc:title :  ExtractContentFromJavaClass
resourceName :  ExtractContentFromJavaClass.class
title :  ExtractContentFromJavaClass