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: #g*U\y
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CountBean.java Gf(hN|X.
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/* O|=5+X
* CountData.java x1</%y5ev
* 56t9h/y
* Created on 2007年1月1日, 下午4:44 6z=h0,Y}
* QE*O~Yj
* To change this template, choose Tools | Options and locate the template under A}pmr
* the Source Creation and Management node. Right-click the template and choose zgRZgVj
* Open. You can then make changes to the template in the Source Editor. =B<>H$
*/ r:lv[/D
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package com.tot.count; ~=91Kxf
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/** EjW3_ %
* ~sT/t1Rp
* @author &NZl_7PL
*/ =(:{>tO_"
public class CountBean { (? j $n?p
private String countType; 8}z]B^?Fy
int countId; gcDo o2RE
/** Creates a new instance of CountData */ ms2y[b
public CountBean() {} =&G<^7
public void setCountType(String countTypes){ |b"
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this.countType=countTypes; ]=\vl>W
} ? 3
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public void setCountId(int countIds){ BH6)`0&2*N
this.countId=countIds; qniP`P4E
} IZ+kw.6e
public String getCountType(){ V}gP'f07zy
return countType; CZ*#FY
} Agt6G\n
public int getCountId(){ &J(+XJM%
return countId; 6 /_] |4t
} IX@g].)C
} 81Ixs
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CountCache.java jej|B#?`
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/* @a-u_|3q
* CountCache.java 8w1TX [b
* pa4,W!t
* Created on 2007年1月1日, 下午5:01 [P~6O>a5p
* qYo"-D*
* To change this template, choose Tools | Options and locate the template under mG4$
* the Source Creation and Management node. Right-click the template and choose -(*<2Hy4
* Open. You can then make changes to the template in the Source Editor. eS)2#=
*/ uG<VQ2LM
W *?mc2;/
package com.tot.count; CR8a)X4j#
import java.util.*; Z3jh-{ 0
/** }*eiG
* vxuxfi8x
* @author !Rp
*/ 4#hDt^N~
public class CountCache { _
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public static LinkedList list=new LinkedList(); \i1>/`F
/** Creates a new instance of CountCache */ lS1-e0,h1
public CountCache() {} R-odc,P=
public static void add(CountBean cb){ L(Ww6oj
if(cb!=null){ O`Ht|@[6
list.add(cb); CUJP"u>8M
} eyq\a'tyB
} YbCqZqk
} >!u@>
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CountControl.java F>N3GPRl
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/* x1H?e8
* CountThread.java MtE18m"z
* 9gjI;*(z1
* Created on 2007年1月1日, 下午4:57 _<Hx1l~
* R}~p1=D
* To change this template, choose Tools | Options and locate the template under WH:[Y7D
* the Source Creation and Management node. Right-click the template and choose fpMnA
* Open. You can then make changes to the template in the Source Editor. &qR1fbw"
*/ ]LGp3)T-
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package com.tot.count; Q
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import tot.db.DBUtils; BPf;!.
import java.sql.*; n0nf;E
/** e| AA7
* g~q+a-
* @author ~vf&JH'!
*/ z9> yg_Q
public class CountControl{ *Nfn6lVB
private static long lastExecuteTime=0;//上次更新时间 \Xy]z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 CR*9-Y93
/** Creates a new instance of CountThread */ Cjvgf.>$
public CountControl() {} $lJu2omi1
public synchronized void executeUpdate(){ agQ5%t#
Connection conn=null; 1-z*'Ghys
PreparedStatement ps=null; 9a.r(W[9
try{ NpmPm1Ix .
conn = DBUtils.getConnection(); Znl&.,c)
conn.setAutoCommit(false); X`,4pSQ;
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 1\v$8pP+
for(int i=0;i<CountCache.list.size();i++){ Y>OL2g
CountBean cb=(CountBean)CountCache.list.getFirst(); 6yIl)5/=
CountCache.list.removeFirst(); WW.\5kBl8
ps.setInt(1, cb.getCountId()); $`nKq4Y
ps.executeUpdate();⑴ T9
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//ps.addBatch();⑵ i?7%z`
} {HgW9N(
//int [] counts = ps.executeBatch();⑶ ,!`94{Ggv
conn.commit(); ]U :1NC"
}catch(Exception e){ p(2j7W-/
e.printStackTrace(); ,H{
/@|RW
} finally{ K?l1Gj
try{ Effp^7 3
if(ps!=null) { F~Kd5-I@
ps.clearParameters(); mtfyhFk
ps.close(); to0tH^pD
ps=null; ]mU,y$IQ
} jgiP2k[Xom
}catch(SQLException e){} v\9:G
DBUtils.closeConnection(conn); m wuFXu/
} )9,*s!)9
} 2>{_O?UN
public long getLast(){ >$.u|a
return lastExecuteTime;
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} wf7<#jIq
public void run(){ `[+9n2j
long now = System.currentTimeMillis(); 9"yBO`
if ((now - lastExecuteTime) > executeSep) { =k4yWC5-
//System.out.print("lastExecuteTime:"+lastExecuteTime); /Vpd*obMB
//System.out.print(" now:"+now+"\n"); cz_4cMgxu
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); lYd#pNN
lastExecuteTime=now; kndP?#>
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executeUpdate(); nG#lrYZw
} T[$Sbz`
else{ `1%SXP1
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); v}6YbY Tq
} #Id.MLHxA_
} 1SBc:!2
} qa ![oMKc
//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 )k&pp^q\
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类写好了,下面是在JSP中如下调用。 `92 D]^g
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<% c%.f|/.k
CountBean cb=new CountBean(); -_jV.`t
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); inBd.%Yr
CountCache.add(cb); H*QN/{|RU
out.print(CountCache.list.size()+"<br>"); ~qNpPIrGr
CountControl c=new CountControl(); (l22p
c.run(); YQR*?/?a
out.print(CountCache.list.size()+"<br>"); A!v-[AI[
%>