text/html与text/plain有什么区别？

 MIME是服务器通知客户机传送文件是什么类型的主要方法，客户机浏览器也通过MIME告诉服务器它的参数。

     在网上，如果接收到的文件没有MIME头，就默认它为HTML格式。但这样也不好，因为当MIME的包头是text/plain时，浏览器将直接显示而不关心它的什么字体，颜色之类的参数

 

response.setContentType() 的作用是使客户端浏览器，区分不同种类的数据，并根据不同的MIME调用浏览器内不同的程序嵌入模块来处理相应的数据

 

case "doc": ContentType = "application/msword"; bre

case "doc":
                    ContentType = "application/msword";
                    break;
                case "pdf":
                    ContentType = "application/pdf";
                    break;
                case "jpg":
                case "jpeg":
                    ContentType = "image/jpeg";
                    break;
                case "gif":
                    ContentType = "image/gif";
                    break;          
                case "zip":
                    ContentType = "application/zip";
                    break;
                case "txt":
                    ContentType = "text/plain";
                    break;
                case "htm":
                case "html":
                    ContentType = "text/html";
                    break;             
                case "xls":
                    ContentType = "application/vnd.ms-excel";
                    break;
                case "ppt":
                    ContentType = "application/vnd.ms-powerpoint";
                    break;
                default:
                    ContentType = "application/octet-stream";
                    break;

意思是八进制文件更新，是火狐的更新文件.