有时要为每一篇文章统计其点击次数,如果每一次浏览都要更新一次库的话,那性能在访问量很大的情况下,服务器的压力就会很大了,比较好一点的方法就是先将要更新的数据缓存起来,然后每隔一段时间再利用数据库的批量处理,批量更新库。源码如下: aX`uF<c9
+q'\rpt
CountBean.java ?h6|N%U'
vof8bQ{&
/* 23P&n(.
* CountData.java -=nk,cYn
* u"q56}Q?]
* Created on 2007年1月1日, 下午4:44 vP x/&x
* a M9v
* To change this template, choose Tools | Options and locate the template under u8T@W}FX
* the Source Creation and Management node. Right-click the template and choose uLafO=Q
* Open. You can then make changes to the template in the Source Editor. 1l$2T
y+
=
*/ (IBT|K
QuqznYSY{
package com.tot.count; dpTsTU!\
arDl2T,igF
/** 9Q=VRH:
* @oE
5JM
* @author &nP0T-T5y
*/ gE _+r
public class CountBean { g35!a<JW
private String countType; Vf;&z$D{r
int countId; JD#x+~pb,8
/** Creates a new instance of CountData */ [EDX@Kdq)
public CountBean() {} h <e
public void setCountType(String countTypes){ k?Z:=.YW
this.countType=countTypes; i}VF$XN
} 5X20/+aT
public void setCountId(int countIds){ :ZM9lBY h
this.countId=countIds; O;~e^ <*
} }3^m>i*8
public String getCountType(){
*[{j'7*cc
return countType; lFGuQLuqA{
} &1$d`>fn
public int getCountId(){ r|EN 5
return countId; aOH|[
} ^K;k4oK
} sFc \L9 4
. :Skc
CountCache.java RNi%6A1
\IE![=p\w
/* -NXxxK
* CountCache.java !HvA5'|:}
* $DoR@2~y
* Created on 2007年1月1日, 下午5:01 -N8rs[c
* x="Wqcnj{
* To change this template, choose Tools | Options and locate the template under B+K6(^j,,y
* the Source Creation and Management node. Right-click the template and choose Q,[G?vbj
* Open. You can then make changes to the template in the Source Editor. -B;#pTG
*/ SLKplLO
O;H6`JQ
package com.tot.count; j{%;n40$
import java.util.*; ysz =Xw
/** m+0yf(w
* dymq
Z<
* @author #RBrii-,
*/ v>_@D@pr
public class CountCache { }T@=I&g;
public static LinkedList list=new LinkedList(); &eHRn_st5b
/** Creates a new instance of CountCache */
H)Btm
public CountCache() {} M76p=*
public static void add(CountBean cb){ 5EFt0?G
if(cb!=null){ inWLIXC,
list.add(cb); ,X.[37
} /K#k_k
} I8Aq8XBw
} m\56BP-AM
5dePpF D5
CountControl.java xU.1GI%UPu
fzIs^(:fl
/* }|.<EkA
* CountThread.java |-Uh3WUE6
* YNr"]SA@ ;
* Created on 2007年1月1日, 下午4:57 B&]`OO>O
* $fmTa02q>
* To change this template, choose Tools | Options and locate the template under `,qft[1
* the Source Creation and Management node. Right-click the template and choose (QDKw}O2b
* Open. You can then make changes to the template in the Source Editor. \baY+,Dr+
*/ ZwkUd-=0i
F\ B/q
package com.tot.count; =rA?,74
import tot.db.DBUtils; 4!IuTPmr
import java.sql.*; ./#YUIC
/**
h[W`P%xZ
* :C:6bDQ
* @author !Y ,7%
*/ AS7L
public class CountControl{ cUY-
private static long lastExecuteTime=0;//上次更新时间 iFd
!ED
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 eFG/!b<17
/** Creates a new instance of CountThread */ 3`bQ0-D;
public CountControl() {} fpR|+`k
public synchronized void executeUpdate(){ V|8'3=Z=
Connection conn=null; UxGu1a
PreparedStatement ps=null; <tD,Uu{P
try{ O] @E8<?^
conn = DBUtils.getConnection(); j'D%eQI,V
conn.setAutoCommit(false); ek][^^4o
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); "`>6M&`U
for(int i=0;i<CountCache.list.size();i++){ 0P$1=oK
CountBean cb=(CountBean)CountCache.list.getFirst(); ON,[!pc
CountCache.list.removeFirst(); i#'K7XM2
ps.setInt(1, cb.getCountId()); MgeC-XQM
ps.executeUpdate();⑴ MgXZN{
//ps.addBatch();⑵ o701RG~)
} NiZfaC6V
//int [] counts = ps.executeBatch();⑶ RlOy,/-<
conn.commit(); 2:38CdkYp
}catch(Exception e){ g(@F`W[
e.printStackTrace(); ^Hx}.?1
} finally{ 7hHID>,o9%
try{ 0V:H/qu8>
if(ps!=null) { |'h(S|
ps.clearParameters(); OG5{oH#K
ps.close(); t#^Cem<
ps=null; M& ZKc
} y\T$) XGV
}catch(SQLException e){} {KG}m'lx
DBUtils.closeConnection(conn); +F)EGB%LXs
} uj8saNu
} 287j,'vR
public long getLast(){ QTHY{:Rmu
return lastExecuteTime; t\M6 d6
} 3Bl|~K;-
public void run(){ Z>g72I%X
long now = System.currentTimeMillis(); "V[j&B)P
if ((now - lastExecuteTime) > executeSep) { Ok!P~2J
//System.out.print("lastExecuteTime:"+lastExecuteTime); L]=]/>jQ6
//System.out.print(" now:"+now+"\n"); YK/? mj1x
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ji/`OS-iq
lastExecuteTime=now; }F>RIjj
executeUpdate(); v3DK0 MW
} k=s^-Eiu
else{ ``/L18
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); % !@E)%d0
} Cog }a
} o<nM-"yWb
} {8m&Z36E
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 Ue}1(2.v
1S?~c25=h
类写好了,下面是在JSP中如下调用。 QRju9x
`y>m
>j
<% TAYh#T=S
CountBean cb=new CountBean(); [j6]!p]S$
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); V D#q\
CountCache.add(cb); q /JC\
out.print(CountCache.list.size()+"<br>"); 9C7Npf?~M
CountControl c=new CountControl(); Ae2N"%Ej
c.run(); .q2r!B
out.print(CountCache.list.size()+"<br>"); Bl+\|[yd
%>