请问下面几句是什么意思

Question

     response.setHeader("Pragma","No-cache");
        response.setHeader("Cache-Control","no-cache");
        response.setDateHeader("Expires", 0);
        String copyright = DBstep.iDBManager2000.getCopyRight();//读取许可号
        ServletOutputStream OutBinarry=response.getOutputStream();
        OutBinarry.write(copyright.getBytes());
        OutBinarry.flush();
OutBinarry.close();

Answer 1

 OutBinarry.write(copyright.getBytes());
        OutBinarry.flush();
        OutBinarry.close();

Answer 2

Java code
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);

Answer 3

防止JSP或者Servlet中的输出被浏览器保存在缓冲区中response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
整个代码的意思是输出“许可号”。