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: aIWpgUd`
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CountBean.java *S Z]xrs
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/* R/^;,.
* CountData.java ' 94HVag
* =)]RD%Oq
* Created on 2007年1月1日, 下午4:44 kYd=DY
* ]7h;MR
* To change this template, choose Tools | Options and locate the template under P|aSbsk:I<
* the Source Creation and Management node. Right-click the template and choose H"2,Q
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* Open. You can then make changes to the template in the Source Editor. q93V'[)F
*/ mj y+_
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package com.tot.count; ^$lsmF]^
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/** hrOp9|!m
* wp-3U}P2(
* @author |e3YTLsI
*/ _'s5FlZq
public class CountBean { [@s5v
private String countType; <5sfII
int countId;
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/** Creates a new instance of CountData */ e}L(tXZ
public CountBean() {} P$G|o|h
public void setCountType(String countTypes){ j7HOh|q
this.countType=countTypes; UX'tdB
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} ,k/<Nv;
public void setCountId(int countIds){ @;d7#!:cE
this.countId=countIds; /B
} @(rLn
public String getCountType(){ zU};|Zw
return countType; ;{cl*EN
} jTY{MY Jh
public int getCountId(){ P99s
return countId; 11yS2D
} niM(0p
} 3-2?mV>5
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CountCache.java TC'^O0aZ_
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/* .s@[-!
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* CountCache.java k8"[)lDc.
* %] 7.E
* Created on 2007年1月1日, 下午5:01 eYRm:KC
* V{kgDpB
* To change this template, choose Tools | Options and locate the template under `#N7ym;s@
* the Source Creation and Management node. Right-click the template and choose 7PI|~Ifi
* Open. You can then make changes to the template in the Source Editor. q]t^6m&-
*/ 2c<phmiK
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package com.tot.count; Z7R+'OC
import java.util.*; fBt7#Tc=U
/** MMUw+jM4
* &rxR"^x\
* @author }L*cP;m#
*/ Cqk6I gw
public class CountCache { u@zBE?
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public static LinkedList list=new LinkedList(); L"!BN/i_
/** Creates a new instance of CountCache */ 9Uh nr]J.
public CountCache() {} bDPT1A`F
public static void add(CountBean cb){ S b3@7^
if(cb!=null){ pF"IDC
list.add(cb); wD&b[i
} b%,`;hy{
} T/C1x9=?
} Bhrp"l
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CountControl.java ffYiu4$m
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/* CR$5'#11)
* CountThread.java vd<"
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* Y,@{1X`0@3
* Created on 2007年1月1日, 下午4:57 AHR[i%3W
* P1ab2D
* To change this template, choose Tools | Options and locate the template under 6y9#am?
* the Source Creation and Management node. Right-click the template and choose ;=6~,k)
* Open. You can then make changes to the template in the Source Editor. f/qG:yTV`
*/ s0"1W"7vh
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package com.tot.count; DP9hvu/85
import tot.db.DBUtils; &u_f:Pog
import java.sql.*; f z8eL:i:
/** _`zj^*%
* MLcc
* @author ZWSYh>"
*/ pemb2HQ'4j
public class CountControl{ LdAfY0
private static long lastExecuteTime=0;//上次更新时间 Ro?aDrQ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 a ^b_&}y
/** Creates a new instance of CountThread */ l7P~_X_)"
public CountControl() {} igsJa1F
public synchronized void executeUpdate(){ m>'sM1s
Connection conn=null; iVt6rX
PreparedStatement ps=null; b^\u
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try{ q8.K-"f(Q
conn = DBUtils.getConnection(); ,!3G
conn.setAutoCommit(false); aQaO.K2
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Nd*zSsVlq
for(int i=0;i<CountCache.list.size();i++){ oToUpkAI
CountBean cb=(CountBean)CountCache.list.getFirst(); g#1_`gK
CountCache.list.removeFirst(); Cv|ya$}a
ps.setInt(1, cb.getCountId()); %@5f+5{i!z
ps.executeUpdate();⑴ YzSUJ=0/
//ps.addBatch();⑵ ;K0kQ<y-Y
} nJ4i[j8
//int [] counts = ps.executeBatch();⑶ @U(D&_H,K
conn.commit(); QOkPliX
}catch(Exception e){ n=n!Hn
e.printStackTrace(); :0j9
} finally{ >v`lsCGb
try{ }Z-]m
if(ps!=null) {
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ps.clearParameters(); m6)8L?B
ps.close(); eqQA st#~
ps=null; 70l" [Y
} |Gb"%5YD
}catch(SQLException e){} w9h\J#f
DBUtils.closeConnection(conn); Ex~[Hk4ow
} HKCMKHR
} b}p 0&%I
public long getLast(){ j9sf~}D>
return lastExecuteTime; 7^h?<X\
} o jzO?z
public void run(){ `(?E-~#'
long now = System.currentTimeMillis(); utC]GiR
if ((now - lastExecuteTime) > executeSep) { -#H>kbs
//System.out.print("lastExecuteTime:"+lastExecuteTime); :Q=Jn?Gjb
//System.out.print(" now:"+now+"\n"); s2Ivd*=mT
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); e;R5A6|
lastExecuteTime=now; RZ9vQ\X
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executeUpdate(); Hm4:m$=p4
} ;OQ{
else{ HjV3PFg
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); xjiMM>|n
} nM1U=Du
} R}a,.C
} ~oh=QakW
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 el39HB$
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类写好了,下面是在JSP中如下调用。 {=j!2v#8~
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<% 0n|op:]BHM
CountBean cb=new CountBean(); #Na3eHT
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); $ckX H,l_
CountCache.add(cb); 6+A<_r`#Q
out.print(CountCache.list.size()+"<br>"); 900#K
CountControl c=new CountControl(); &F*s.gL
c.run(); xWD=",0+
out.print(CountCache.list.size()+"<br>"); :f?\ mVS+
%>