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: <xz-7EqbwX
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CountBean.java ~&|i'f[
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/* E&v-(0
* CountData.java 82l";;n4p
* gvt4'kp
* Created on 2007年1月1日, 下午4:44 0kEq|k9
* skArocs
* To change this template, choose Tools | Options and locate the template under RtEkd_2
* the Source Creation and Management node. Right-click the template and choose l'R`XGT
* Open. You can then make changes to the template in the Source Editor. IMEoov-x
*/ +T;qvx6
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package com.tot.count; lK@r?w|<M
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/** : P2;9+v
* ~qxc!k!w4
* @author 2M`Ni&v
*/ ^ZBkt7
public class CountBean { m>:ig\
private String countType; nJw1Sl5
int countId; j
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/** Creates a new instance of CountData */ ^jC0S[csw2
public CountBean() {} ovVU%2o1b
public void setCountType(String countTypes){ }RK9Onh3G
this.countType=countTypes; RH'R6
} >r Glj
public void setCountId(int countIds){ SjU6+|l
this.countId=countIds; m8`A~
} 1 crjRbi
public String getCountType(){ F.hC%Ncu
return countType; OQyOv%g5C
} % QkvBg*
public int getCountId(){ 1yf&ck1R
return countId; 1Pc'wfj
} 7%WI
} O;tn5
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CountCache.java ]t<%>Z$
/ nRaxzf'
/* 3EdPKM j&
* CountCache.java :eO0{JN4T
* nQC[[G*x
* Created on 2007年1月1日, 下午5:01 o!d0
* rkp0ej2-
* To change this template, choose Tools | Options and locate the template under Su^Z{ Ud`
* the Source Creation and Management node. Right-click the template and choose 3e:y?hpeL
* Open. You can then make changes to the template in the Source Editor. -z94>}Z=
*/ B5S1F4
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package com.tot.count; 'ZZ/:MvQa
import java.util.*; {^iV<>J
/** ]5CFL$_Q{
* dY^~^<{Lj
* @author MDt4KD+bZ
*/ .d,Zx
public class CountCache { >n62csO
public static LinkedList list=new LinkedList(); p`0Tpgi
/** Creates a new instance of CountCache */ B7C6Mau
public CountCache() {} co|0s+%PBq
public static void add(CountBean cb){ }qg&2M%\
if(cb!=null){ \zU R9h
list.add(cb); ,.B8hr@H6-
} cQ%HwYn
} v4G kf
} uR[i9%=8L(
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CountControl.java #B[>\D"*
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/* rCYn YA
* CountThread.java hR2.w/2j
* K(Nk|gQ
* Created on 2007年1月1日, 下午4:57 &/"
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* Ar_/9@n
* To change this template, choose Tools | Options and locate the template under 5irOK9hK
* the Source Creation and Management node. Right-click the template and choose ah.Kb(d:
* Open. You can then make changes to the template in the Source Editor. WJWrLu92\U
*/ NgQl;$
w6tY6bf}
package com.tot.count; SQ[}]Tm;n
import tot.db.DBUtils; }#1{GhsS
import java.sql.*; Q*5d~Yr ]R
/** |k0VJi
* V^D#i(5
* @author Gy5W;,$q
*/ qn .
public class CountControl{ uB?YJf .T@
private static long lastExecuteTime=0;//上次更新时间 TnrMR1Zx
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 JP]K\nQx'
/** Creates a new instance of CountThread */ H+Wd#7l,
public CountControl() {} .0
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public synchronized void executeUpdate(){ \v<}{\.|$
Connection conn=null; R:E:Y|&#
PreparedStatement ps=null; L xO'$oKZV
try{ 0J"3RTt
conn = DBUtils.getConnection(); &W%TY:Da|
conn.setAutoCommit(false); _nt%&f
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); !E8JpE|z#
for(int i=0;i<CountCache.list.size();i++){ ,$Mw/fA
CountBean cb=(CountBean)CountCache.list.getFirst(); :d;5Q\C`
CountCache.list.removeFirst(); 2t'&7>Ys{
ps.setInt(1, cb.getCountId()); :>;#/<3{
ps.executeUpdate();⑴
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//ps.addBatch();⑵ S;C3R5*:
} gVc[`(@h
//int [] counts = ps.executeBatch();⑶ 0qv)'[O
conn.commit(); oT'XcMn
}catch(Exception e){ Jq->DzSmj/
e.printStackTrace(); w K+2;*bI
} finally{ =W6P>r_
try{ :zCm$@
if(ps!=null) { fHiCuF
ps.clearParameters(); mTt 9 o9E
ps.close(); T
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ps=null; E_z@\z MB
} Zo`^pQS
}catch(SQLException e){} )xeVoAg
DBUtils.closeConnection(conn); 7hc(]8eP
} t%%I.zIV7
} `u-}E9{
public long getLast(){ n\ZFPXP
return lastExecuteTime; 5"sF#Y&
} ifkA3]
public void run(){ 0-FbV,:;
long now = System.currentTimeMillis(); _i&\G}mrC
if ((now - lastExecuteTime) > executeSep) { mnePm{
//System.out.print("lastExecuteTime:"+lastExecuteTime); $T6<9cB@
//System.out.print(" now:"+now+"\n"); >&TktQO_T
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); T'X Rl@
lastExecuteTime=now; OCd[P1Y]
executeUpdate(); Sa Nx;xgi
} $]vR ,E
else{ {>:2Ff]O:
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); cIX59y#7
} :p{iBDA
} f,$CiZ"
} `4o;Lz~
//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 &45.*l|mo
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类写好了,下面是在JSP中如下调用。 o8" [6Ys
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<% O;XF'r_
CountBean cb=new CountBean(); Og["X0j
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); uGv+c.~[j
CountCache.add(cb); 1+^c3Dd`
out.print(CountCache.list.size()+"<br>"); %l,Xt"nS#
CountControl c=new CountControl(); !#r]f9QP
c.run(); 6l=n&YO
out.print(CountCache.list.size()+"<br>"); {Hb _o)S
%>