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: {%<OD8>p
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CountBean.java 52SaKA[
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/* {\S+#W\
* CountData.java bHPYp5UwN
* *}]Nf
* Created on 2007年1月1日, 下午4:44 K-e9>fmB#
* Qt iDTr
* To change this template, choose Tools | Options and locate the template under 3[\iQ*d }B
* the Source Creation and Management node. Right-click the template and choose :H7D~ n
* Open. You can then make changes to the template in the Source Editor. VCu{&Sh*
*/ TMAJb+@l:
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package com.tot.count; C+?Hm1
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/** {G|,\O1
* 9:fOYT$8
* @author D;oe2E{I
*/ c;%_EN%
public class CountBean { nA?`BOe(
private String countType; Ot:CPm@
int countId; VcAue!MN
/** Creates a new instance of CountData */ I[=j&rK`
public CountBean() {} 8;z6=.4xtg
public void setCountType(String countTypes){ 3 ,>0a
this.countType=countTypes; g3Ec"_>P
} 3b*cU}go
public void setCountId(int countIds){ {n(b{ibl
this.countId=countIds; ~hZ"2$(0
} -#0qV:D
public String getCountType(){ kUq=5Y `D
return countType; *n;!G8\
} cmBB[pk\
public int getCountId(){ `D>S;[~S7
return countId; FjK3
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} F
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} &yGaCq;0
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CountCache.java bnm
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/* {xwm^p(f
* CountCache.java 4S,`bnmB
* cYFiJJLG]
* Created on 2007年1月1日, 下午5:01 _Bj)r}~7#
* e.]K L('
* To change this template, choose Tools | Options and locate the template under >QA uEM
* the Source Creation and Management node. Right-click the template and choose -0?~
* Open. You can then make changes to the template in the Source Editor. JQ}$Aqk
*/ anIAM
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package com.tot.count; cS>e?
import java.util.*; SPN5dE.@
/** T~QWRBO
* %R@X>2l/_
* @author 8'~[pMn`
*/ D-8O+.@
public class CountCache { #6ri-n
public static LinkedList list=new LinkedList(); .}'qUPNR
/** Creates a new instance of CountCache */ D<|qaHB=
public CountCache() {} JXCCTUO
public static void add(CountBean cb){ eK.e|z|
if(cb!=null){ /3;4#:Kkw
list.add(cb); W4[V}s5u
} !v X D
} ZaeqOVp/j
} $"0M U
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CountControl.java k:JrHBKv\
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/* =3q/F7-
* CountThread.java s >e=?W
* 7s"<
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* Created on 2007年1月1日, 下午4:57 ~2<7ZtV=
* w:s]$:MA8
* To change this template, choose Tools | Options and locate the template under uvtF_P/
* the Source Creation and Management node. Right-click the template and choose i-bJS6
* Open. You can then make changes to the template in the Source Editor. /TZOJE(2j
*/ m<{<s T
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package com.tot.count; $Z|ffc1
import tot.db.DBUtils; T?:glp[4I
import java.sql.*; JAAI_gSR3
/** VUVaaOmO
* _{R=B8Zz\
* @author `VKf3&|<A
*/ R<sJ^nx
public class CountControl{ YGv<VOWG2
private static long lastExecuteTime=0;//上次更新时间 W5?yy>S6N
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 vr0WS3
/** Creates a new instance of CountThread */ uwa~-xX6
public CountControl() {} 1U^A56CN
public synchronized void executeUpdate(){ 43={Xy
Connection conn=null; ]Tkc-ez
PreparedStatement ps=null; BhM'@g*
try{ 5m?8yT}
conn = DBUtils.getConnection(); 9so6WIWc
conn.setAutoCommit(false); =
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); [[>wB[w
for(int i=0;i<CountCache.list.size();i++){ ta`N8vnf
CountBean cb=(CountBean)CountCache.list.getFirst(); $ "E).j
CountCache.list.removeFirst(); w;k):;$
ps.setInt(1, cb.getCountId()); %CS@g.H=_
ps.executeUpdate();⑴ A,\6nO67
//ps.addBatch();⑵ Kl2lbe7
} %^I88,$&L
//int [] counts = ps.executeBatch();⑶ OH5>vV'i
conn.commit(); 6&bY} i^K
}catch(Exception e){ #<e\QE'!
e.printStackTrace(); Bn61AFy`
} finally{ pY_s*0_
try{ Kv.>Vf.T}_
if(ps!=null) { z;A>9vQ_J
ps.clearParameters(); 3 n'V\Hvz
ps.close(); ~_Lr=C D;4
ps=null; n) k1
} Gm9hYhC8
}catch(SQLException e){} ,WJH}(h"D
DBUtils.closeConnection(conn); uiJS8(Cb
} ,0E{h}(
} taFn![}/!g
public long getLast(){ iC W*]U
return lastExecuteTime; 4hAl-8~Q6
} %F:)5gT?
public void run(){ /ODXV`3QYI
long now = System.currentTimeMillis(); 2RN)<\ P
if ((now - lastExecuteTime) > executeSep) { hGbj0
//System.out.print("lastExecuteTime:"+lastExecuteTime); :WSDf VX
//System.out.print(" now:"+now+"\n"); hSFn8mpXT
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); c)A{p
lastExecuteTime=now; ^|/](
executeUpdate(); dn}` i
} 0pJ
":Q/2)
else{ 5v?;PX
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 2Fz|fW_
} [8Qro8
} =QK$0r]c'k
} -T&.kYqnb$
//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 srYJp^sC
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类写好了,下面是在JSP中如下调用。 Ea?XT&,
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<% ]~6_ WE8L
CountBean cb=new CountBean(); ] )F7)
cb.setCountId(Integer.parseInt(request.getParameter("cid")));
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CountCache.add(cb); `;l?12|X
out.print(CountCache.list.size()+"<br>"); ^S)cjH`P
CountControl c=new CountControl(); TYlbU<
c.run(); b8%C*r7
out.print(CountCache.list.size()+"<br>"); ?W0)nQU
%>