code: public static void write(String text, String contentType) {
  		setContentType(contentType);
  		Writer writer = null;
  		try {
  			writer = getWriter();
  			writer.write(text);
  			writer.flush();
  		} catch (IOException e) {
  			throw new RenderException("Error when output to client!", e);
  		} finally {
  			IoUtil.close(writer);
  		}
  	}
docs: 返回数据给客户端
  
  @param text 返回的内容
  @param contentType 返回的类型