code: public void save() throws IOException {
  	if (!file.exists()) file.createFile(true);
  	OutputStream out = IOUtil.toBufferedOutputStream(file.getOutputStream());
  	Iterator it = sections.keySet().iterator();
  	PrintWriter output = new PrintWriter(out);
  	try {
  	    while (it.hasNext()) {
  		String strSection = (String) it.next();
  		output.println("[" + strSection + "]");
  		Map section = getSectionEL(strSection);
  		Iterator iit = section.keySet().iterator();
  		while (iit.hasNext()) {
  		    String key = (String) iit.next();
  		    output.println(key + "=" + section.get(key));
  		}
  	    }
  	}
  	finally {
  	    IOUtil.flushEL(output);
  	    IOUtil.closeEL(output);
  	    IOUtil.flushEL(out);
  	    IOUtil.closeEL(out);
  	}
      }
docs: save back content to ini file
  
  @throws IOException