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;
begintime = sdf.format(new java.util.Date(myTime));
endtime = sdf.format(myDate);
//System.out.println("------"+begintime+"+++++"+endtime);
}else if(timeRange.equals("30")){
myTime=((myDate.getTime()/1000)-60*60*24*30)*1000;
begintime = sdf.format(new java.util.Date(myTime));
endtime = sdf.format(myDate);
//System.out.println("------"+begintime+"+++++"+endtime);
}

sql.append("publishtime between "+"'"+begintime+"'"+" and "+"'"+endtime+"' and " );
}

if((type == null)||(type.equals(""))){
sql.append("t.typename like '%' ");
}else{
sql.append("t.typename like '"+type+"'");
}

sql.append(" order by f.publishtime desc;");

String searchSQL = sql.toString();