java时间函数，以及 sql 时间范围查找 代码

 String keyword = request.getParameter("keyword");
   String timeRange = request.getParameter("timeRange");
   String type = request.getParameter("type");
  
   StringBuffer sql = new StringBuffer();
   sql.append("use webstation_leadall select f.id,f.title,f.publishtime from information f left join infotype t on f.typeid=t.id  where ");
   if( (keyword == null)|| (keyword.equals("")) ){  
   sql.append("title like '%' and ");
  }else {
   sql.append("title like '%"+keyword +"%' and ");
  }
  
  if(timeRange.equals("")||timeRange==null){
   sql.append("");
  }else{
   //Calendar cal = Calendar.getInstance();
   SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd kk:mm:ss");
      //String now = sdf.format(cal.getTime());
   String begintime = "";
   String endtime = "";
   java.util.Date myDate=new java.util.Date();
   long myTime = 0;
   if(timeRange.equals("1")){
    myTime=((myDate.getTime()/1000)-60*60*24)*1000;
    begintime = sdf.format(new   java.util.Date(myTime));
    endtime = sdf.format(myDate);
    //System.out.println("------"+begintime+"+++++"+endtime);
   }else if(timeRange.equals("3")){
    myTime=((myDate.getTime()/1000)-60*60*24*3)*1000;
    begintime = sdf.format(new   java.util.Date(myTime));
    endtime = sdf.format(myDate);
    //System.out.println("------"+begintime+"+++++"+endtime);
   }else if(timeRange.equals("7")){
    myTime=((myDate.getTime()/1000)-60*60*24*7)*1000;
 &n