last modify尝试

web层的尝试：

javascirpt代码，通过ajax添加请求头,可以达到返回304 not modify,但是需要js自行把数据缓存,否则返回后没有数据展示。

 

//			var date = date_ddmmmyy(new Date(Date.parse(document.lastModified)));
//			var time = document.lastModified.substring(document.lastModified.indexOf(" "));
//			heads ={'Last-Modified':date+time};

 

		//set the last-modify-head
		if(heads){
			if(heads['Last-Modified'])
				this._request.setRequestHeader("If-Modified-Since",heads['Last-Modified']);
		}
		//set the last-modify-hea

 

 

 

//
// format date as dd-mmm-yy
// example: 12-Jan-99
//
function date_ddmmmyy(date)
{
  var d = date.getDate();
  var m = date.getMonth() + 1;
  var y = date.getYear();

  // handle different year values 
  // returned by IE and NS in 
  // the year 2000.
  if(y >= 2000)
  {
    y -= 2000;
  }
  if(y >= 100)
  {
    y -= 100;
  }

  // could use splitString() here 
  // but the following method is 
  // more compatible
  var mmm = 
    ( 1==m)?'Jan':( 2==m)?'Feb':(3==m)?'Mar':
    ( 4==m)?'Apr':( 5==m)?'May':(6==m)?'Jun':
    ( 7==m)?'Jul':( 8==m)?'Aug':(9==m)?'Sep':
    (10==m)?'Oct':(11==m)?'Nov':'Dec';

  return "" +
    (d<10?"0"+d:d) + "-" +
    mmm + "-" +
    (y<10?"0"+y:y);
}

 

后台java处理

org.springframework.web.context.request.WebRequest		

//check is modify
		if(webRequest.checkNotModified(lastModifyTime)){
			return null;
		}